User login
Advances in Cutaneous Molecular Medicine Supplement Clinical Expertise
To sustain the role of expert in cutaneous medicine, dermatologists and dermatopathologists must embrace the molecular advances in medicine, according to Dr. Pedram Gerami.
"For the vast majority of dermatologists and dermatopathologists trained in traditional clinical medicine, the sheer volume of newly identified gene mutations, chromosomal aberrations, and related molecular tests, even within a focused area of specialization, is truly overwhelming. As in many aspects of life, such rapid and transformative changes may be met with welcome or resistance," wrote Dr. Gerami, who was a guest editor of the December issue of Seminars in Cutaneous Medicine and Surgery, which focused on molecular medicine.
Rather than giving in to the common fear that new technological advancements may replace years of clinical training, it is important to recognize that these advances are meant to supplement – not replace – the clinical expertise of dermatologists and dermatopathologists (Sem. Cut. Med. Surg. 2012;31:203).
"The greatest threat to our practice is not the technologic advancement but rather loss of certain aspects of our practice to other specialties [that] better embrace the molecular revolution," he said, adding that active leadership with respect to integrating molecular medicine into the specialty will have a protective effect.
The first step is gaining a deeper understanding of these rapidly emerging advances. Among them are:
Diagnosis of Cutaneous Soft-Tissue Tumors
The identification of genetic abnormalities that characterize soft-tissue tumors has led to the development of diagnostic molecular testing, according to Dr. Alison L. Cheah and Dr. Steven D. Billings, both of the department of anatomic pathology at the Cleveland Clinic.
"Specific genetic signatures characterize a growing number of soft-tissue tumors that affect the skin. Molecular testing on FFPE [formalin-fixed paraffin-embedded tissue] complements histology and immunohistochemistry in the diagnosis of these tumors, especially in challenging cases with atypical morphology, nonspecific immunophenotype, and/or limited sampling," they wrote.
Molecular diagnostics also has implications for more accurate classification and prognostication of poorly understood entities (Sem. Cut. Med. Surg. 2012;31:221-33). "The identification of these disease-defining genetic signatures is the basis for the development of targeted therapies," they wrote.
Take dermatofibrosarcoma protuberans (DFSP), for example. "In practice, molecular testing in DFSP has utility both as a diagnostic aid in challenging cases and to guide therapy," they explained.
While most cases are easily diagnosed based on histopathologic features, significant diagnostic challenges can arise in certain cases, such as in CD34-negative tumors that are superficially sampled, or in tumors with varying histology or an unusual presentation.
For guiding treatment, molecular testing can be helpful for confirmation of COL1A1-PDGF-beta, which is vital if treatment with imatinib mesylate is being considered, because tumors lacking the fusion gene do not respond to this drug, they noted. Imatinib mesylate recently received Food and Drug Administration approval for the treatment of unresectable metastatic or recurrent DFSP.
Real-time polymerase chain reaction (RT-PCR) is the most studied test for detecting COL1A1-PDGF-beta and has a reported sensitivity between 74% and 96%. Though not as well studied, fluorescence in situ hybridization (FISH) assays also show promise.
"FISH assays using both PDGF-beta break-apart and COL1A1-PDGF-beta dual-color dual-fusion probe techniques have also been used," they wrote, noting that some reports show a greater sensitivity of FISH than RT-PCR for DFSP.
Molecular assays can also be helpful in confirming the diagnosis of angiomatoid fibrous histiocytoma (AFH).
In a study of 17 cases, FISH assays with dual-color break-apart probes had a sensitivity of 76% for identifying EWSR1 and FUS gene rearrangements, regardless of the translocation partner, they noted. FISH results should be interpreted with caution, though, because a negative result does not rule out the diagnosis of AFH, as rearrangements that are not detectable with the particular FISH probes used, or translocations with different chromosomes altogether, could explain a negative FISH result.
"Of note, EWSR1 rearrangements occur in several other soft tissue sarcomas, including Ewing sarcoma family of tumors, desmoplastic small round-cell tumors, clear cell sarcoma, extraskeletal myxoid chondrosarcoma, and a subset of myoepithelial tumors," they noted, adding that correlation with the histologic and immunohistochemical findings remains paramount.
RT-PCR is also a sensitive and specific assay for AFH, but its practical utility is limited by the multiple primers to account for the various fusion transcripts described in AFH.
Another area in which molecular testing plays an important role – albeit complementary– is in the diagnosis of low-grade fibromyxoid sarcoma (LGFMS), they reported. On the basis of RT-PCR results, for example, a significant number of cases previously diagnosed as LGMFS had to be reclassified.
RT-PCR assays performed on FFPE tissues had a sensitivity of 81%-88%, and FISH testing for FUS gene rearrangement is less sensitive at about 70%, but is nonetheless a good alternative to PCR, particularly in paraffin blocks with poor quality RNA.
These are just a few of the areas discussed by Dr. Cheah and Dr. Billings, with respect to molecular testing for cutaneous soft tissue tumors. Others addressed in their article were clear-cell sarcoma (melanoma of the soft parts), postradiation angiosarcoma, epithelioid hemangioendothelioma, and Ewing sarcoma family of tumors.
Knowledge and identification of the recurrent molecular aberrations in these cutaneous mesenchymal tumors allow for more accurate diagnosis and advancement of understanding about their underlying biology.
BRAF V600E Mutation Detection
The identification of BRAF mutations in the mitogen-activated protein kinase pathway revolutionized the treatment of advanced-stage melanoma, bringing selective small-molecule RAF inhibitors, such as vemurafenib, to the clinical trial stage. In the phase III BRIM-3 trial, vemurafenib was associated with a higher response rate and a significant improvement in survival, compared with dacarbazine.
"The knowledge that melanomas harbor recurring hot spot mutations in the BRAF gene has rapidly brought molecular testing to the clinical stage," wrote Dr. Jonathan L. Curry of the department of pathology at the University of Texas MD Anderson Cancer Center, Houston, and his colleagues.
The cobas 4800 BRAF V600 Mutation Test from Roche, for example, was approved by the FDA as an in vitro diagnostic device to detect mutant BRAF V600E in DNA extracted from a FFPE patient’s sample of melanoma (Sem. Cut. Med. Surg. 2012;31:268-74). The presence of the mutation aids in selecting patients for treatment with vemurafenib.
The authors noted that a number of molecular platforms for BRAF testing have been developed and continue to evolve, offering a more thorough and complex analysis of the genetic components of melanoma.
"The next generation sequencing or massively parallel sequencing will allow sequencing of the entire exon or whole genome. Multiple sequencing molecular platforms are available to examine for BRAF mutations in cutaneous melanoma, and the best technological approach continues to be developed," they wrote.
Among those they described are:
• Sanger Sequencing. Sanger chain–termination sequencing of amplified DNA by PCR was the method used to sequence the human genome, and the Sanger method of sequencing led to the detection of BRAF mutations in cutaneous melanoma. Sensitivity is high (fewer than 5% of tumor cells are necessary in a given specimen), but use in the clinical setting is limited to BRAF testing. Although it remains the gold standard for gene sequencing, the Sanger method has technical and practical limitations. For example, it takes 18-19 hours to perform the test, other tests are more sensitive, and it cannot detect changes in the chromosomal copy number and the translocations.
• Pyrosequencing. Also known as sequencing by synthesis, pyrosequencing is among the platforms more sensitive than Sanger sequencing. The detection ratio of mutant BRAF V600E to wild type is 1:5 for Sanger sequencing, and 1:50 for pyrosequencing. Its clinical application is to detect the presence or absence of known mutations within a specific segment of DNA of a single nucleotide polymorphism.
"Because mutations in melanoma appear to cluster in the BRAF, NRAS, and KIT genes, this molecular platform has been readily incorporated into the mutational analysis of melanoma," the authors explained, noting that pyrosequencing is a rapid and sensitive test for detection of more common BRAF V600E mutations, as well as other variants. It is limited to the length of the DNA template sequenced, and is prone to errors reading through homopolymer sequences.
• Allele-Specific Real-Time PCR. This molecular platform, also known as the amplification-refractory mutation system, enriches known mutations in clinical samples to increase sensitivity of detection, and is particularly useful in FFPE biopsies with low tumor content. It is highly sensitive and is confined to known BRAF mutations that occur in melanomas, but demonstrates greater sensitivity in detecting BRAF V600E mutations in FFPE clinical samples.
• Mass Spectrometry–Based Sequencing (Sequenom). Sequenom uses mass spectrometry to determine the sequence of the FFPE tissue samples of melanoma. The platform allows for simultaneous amplification of multiple genetic hot spots, allowing for analysis of several known mutations in a single clinical sample. In the authors’ experience, it has slightly higher sensitivity than pyrosequencing.
• High Resolution Melting (HRM). Also a highly sensitive method for screening for mutations in clinical samples, high-resolution melting relies on PCR amplification of the DNA template and analysis of the temperature gradient in which the double strands of the PCR products are melted. The strands melt at different temperatures, depending on the sequence of the constituent bases, allowing for detection of the mutant allele in the FFPE tissue sample. An important limitation of this approach is that specific nucleotide alteration is not reported, thus tissues samples that are positive for mutations will require additional sequencing by another method to determine the specific nucleotide alteration.
• The 454 Pyrosequencing (Roche). This powerful platform, one of several next generation sequencing technologies that allows ultra deep sequencing of entire exons, was used to resolve mutation discrepancies between the cobas 4800 BRAF V600 test and the Sanger sequencing method during the vemurafenib trials, the authors noted. It has a mean error rate of only 1.07%, with more than half of the errors at sites of homopolymers, has the lengths of individual reads of DNA sequences of more than 500 base pairs, and can be performed in less than a day.
• Cobas 4800 BRAF V600 Mutation Test. The cobas 4800 BRAF V600 Mutation Test is based on the principles of allele-specific real time PCR, and targets a predefined 116-base pair sequence of the BRAF gene on exon 15. The device, which is intended to identify those with BRAF V600E who might benefit from therapy with vemurafenib, has a sensitivity for detecting BRAF V600E on FFPE samples of melanoma of more than 99%, and a specificity of 88%. The sensitivity appears comparable with the other platforms, including Sequenom and HRM.
Although the platform is not designed to screen for nonrecurrent genetic mutations in melanoma, BRAF V600E appears to account for the highest percentage of mutations in cutaneous melanomas, the authors said.
Cutaneous Lymphoma Analysis
In cutaneous lymphomas, molecular analysis serves to confirm the diagnosis in cases in which the clinical and/or pathologic presentations do not provide a diagnosis and to further characterize the nature of the lymphoma, according to Dr. Janyana M.D. Deonizio and Dr. Joan Guitart.
While the gold standard for diagnosis is a solid clinicopathologic correlation, molecular analysis provides for a more concrete diagnosis that helps both the patient in facing the diagnosis, and the clinician in proceeding with the most appropriate treatment plan (Sem. Cut. Med. Surg. 2012;31:234-40).
Specifically, through immunophenotyping and clonality analysis, molecular analysis helps discern whether the lymphoma is primarily cutaneous or systemic with secondary skin involvement, and it subclassifies the tumor.
Methods for establishing T-cell clonality include Southern blot analysis (SBA) and PCR for detection of specific T-cell receptor gene arrangements (TCR-GR). SBA used to be the gold standard, but has been gradually replaced by PCR techniques which are less laborious and lengthy. PCR sensitivity for T-cell clonality detection ranges from 70% to 90%.
"Ideally, TCR clonality should be checked at the time of diagnosis in skin and blood. ... The detection of a dominant clone is important not only to confirm diagnosis but also for some prognostic guidance," they wrote, explaining that T-cell cloning is particularly helpful when early-stage mycosis fungoides is being considered in the differential diagnosis.
It does have limitations, however. False-positive monoclonal or oligoclonal bands may be identified in inflammatory dermatoses when T-cell infiltrates are sparse, resulting in "pseudomonoclonality," which is infrequently associated with a malignant T-cell process, they noted.
"Repeating the analysis using the same DNA template or fresh DNA extraction may solve the problem because in reactive conditions, the predominant PCR products typically vary in repeated PCR analyses of the same sample. In contrast, in neoplastic T-cell proliferations, dominant TCR clones are reproducible and should be routinely verified to confirm monoclonality," they noted.
Some studies suggest a correlation between TCR clonality by PCR and response to treatment; the absence of a detectable clone in cutaneous T-cell lymphoma (CTCL) has been associated with a higher rate of complete remission – although not necessarily with improved survival.
Immunophenotypic and immunogenotypic assays have been used to monitor the response of CTCL to therapy, define remission, and detect early relapse, thereby improving assessment of disease activity.
Flow cytometry analysis, for example, is "an efficient and sensitive method to detect and enumerate abnormal cells in the peripheral blood or any other cell suspension," they wrote. It can also be performed on leukocyte suspension from skin biopsies, and it provides prognostic information.
"Lower counts of circulating CD8+ lymphocytes and higher white cell counts in CTCL patients are associated with a less favorable prognosis," the authors noted.
FISH is used to detect major chromosomal gains or losses and specific translocations using a target-specific probe. Although FISH is not routinely used in the diagnosis of cutaneous lymphomas, it does appear to have potential future applications in various areas, according to recent publications.
Finally, genomic analysis by microarray-based comparative genomic hybridization is allowing quantification and appositional defining of chromosomal imbalances. While still confined to the research arena, this technology is providing some insight into the molecular pathogenesis of CTCL, the reported.
The advances in molecular diagnostics that are outlined in this series of articles are not limited to skin cancers and tumors. Additional articles, for example, addressed the role of genetic and molecular analysis in alopecia and in genodermatoses. Together they underscore the need for, and substantiate the ability of the specialty to take on leadership roles in molecular medicine, noted Dr. Gerami, of the department of dermatology at Northwestern University in Chicago.
"I am hopeful that they can assist other practicing dermatologists and dermatopathologists acquire a better foundation in molecular medicine, allowing them to sustain their primary roles in cutaneous medicine," Dr. Gerami concluded.
The authors reported having no conflicts of interest.
To sustain the role of expert in cutaneous medicine, dermatologists and dermatopathologists must embrace the molecular advances in medicine, according to Dr. Pedram Gerami.
"For the vast majority of dermatologists and dermatopathologists trained in traditional clinical medicine, the sheer volume of newly identified gene mutations, chromosomal aberrations, and related molecular tests, even within a focused area of specialization, is truly overwhelming. As in many aspects of life, such rapid and transformative changes may be met with welcome or resistance," wrote Dr. Gerami, who was a guest editor of the December issue of Seminars in Cutaneous Medicine and Surgery, which focused on molecular medicine.
Rather than giving in to the common fear that new technological advancements may replace years of clinical training, it is important to recognize that these advances are meant to supplement – not replace – the clinical expertise of dermatologists and dermatopathologists (Sem. Cut. Med. Surg. 2012;31:203).
"The greatest threat to our practice is not the technologic advancement but rather loss of certain aspects of our practice to other specialties [that] better embrace the molecular revolution," he said, adding that active leadership with respect to integrating molecular medicine into the specialty will have a protective effect.
The first step is gaining a deeper understanding of these rapidly emerging advances. Among them are:
Diagnosis of Cutaneous Soft-Tissue Tumors
The identification of genetic abnormalities that characterize soft-tissue tumors has led to the development of diagnostic molecular testing, according to Dr. Alison L. Cheah and Dr. Steven D. Billings, both of the department of anatomic pathology at the Cleveland Clinic.
"Specific genetic signatures characterize a growing number of soft-tissue tumors that affect the skin. Molecular testing on FFPE [formalin-fixed paraffin-embedded tissue] complements histology and immunohistochemistry in the diagnosis of these tumors, especially in challenging cases with atypical morphology, nonspecific immunophenotype, and/or limited sampling," they wrote.
Molecular diagnostics also has implications for more accurate classification and prognostication of poorly understood entities (Sem. Cut. Med. Surg. 2012;31:221-33). "The identification of these disease-defining genetic signatures is the basis for the development of targeted therapies," they wrote.
Take dermatofibrosarcoma protuberans (DFSP), for example. "In practice, molecular testing in DFSP has utility both as a diagnostic aid in challenging cases and to guide therapy," they explained.
While most cases are easily diagnosed based on histopathologic features, significant diagnostic challenges can arise in certain cases, such as in CD34-negative tumors that are superficially sampled, or in tumors with varying histology or an unusual presentation.
For guiding treatment, molecular testing can be helpful for confirmation of COL1A1-PDGF-beta, which is vital if treatment with imatinib mesylate is being considered, because tumors lacking the fusion gene do not respond to this drug, they noted. Imatinib mesylate recently received Food and Drug Administration approval for the treatment of unresectable metastatic or recurrent DFSP.
Real-time polymerase chain reaction (RT-PCR) is the most studied test for detecting COL1A1-PDGF-beta and has a reported sensitivity between 74% and 96%. Though not as well studied, fluorescence in situ hybridization (FISH) assays also show promise.
"FISH assays using both PDGF-beta break-apart and COL1A1-PDGF-beta dual-color dual-fusion probe techniques have also been used," they wrote, noting that some reports show a greater sensitivity of FISH than RT-PCR for DFSP.
Molecular assays can also be helpful in confirming the diagnosis of angiomatoid fibrous histiocytoma (AFH).
In a study of 17 cases, FISH assays with dual-color break-apart probes had a sensitivity of 76% for identifying EWSR1 and FUS gene rearrangements, regardless of the translocation partner, they noted. FISH results should be interpreted with caution, though, because a negative result does not rule out the diagnosis of AFH, as rearrangements that are not detectable with the particular FISH probes used, or translocations with different chromosomes altogether, could explain a negative FISH result.
"Of note, EWSR1 rearrangements occur in several other soft tissue sarcomas, including Ewing sarcoma family of tumors, desmoplastic small round-cell tumors, clear cell sarcoma, extraskeletal myxoid chondrosarcoma, and a subset of myoepithelial tumors," they noted, adding that correlation with the histologic and immunohistochemical findings remains paramount.
RT-PCR is also a sensitive and specific assay for AFH, but its practical utility is limited by the multiple primers to account for the various fusion transcripts described in AFH.
Another area in which molecular testing plays an important role – albeit complementary– is in the diagnosis of low-grade fibromyxoid sarcoma (LGFMS), they reported. On the basis of RT-PCR results, for example, a significant number of cases previously diagnosed as LGMFS had to be reclassified.
RT-PCR assays performed on FFPE tissues had a sensitivity of 81%-88%, and FISH testing for FUS gene rearrangement is less sensitive at about 70%, but is nonetheless a good alternative to PCR, particularly in paraffin blocks with poor quality RNA.
These are just a few of the areas discussed by Dr. Cheah and Dr. Billings, with respect to molecular testing for cutaneous soft tissue tumors. Others addressed in their article were clear-cell sarcoma (melanoma of the soft parts), postradiation angiosarcoma, epithelioid hemangioendothelioma, and Ewing sarcoma family of tumors.
Knowledge and identification of the recurrent molecular aberrations in these cutaneous mesenchymal tumors allow for more accurate diagnosis and advancement of understanding about their underlying biology.
BRAF V600E Mutation Detection
The identification of BRAF mutations in the mitogen-activated protein kinase pathway revolutionized the treatment of advanced-stage melanoma, bringing selective small-molecule RAF inhibitors, such as vemurafenib, to the clinical trial stage. In the phase III BRIM-3 trial, vemurafenib was associated with a higher response rate and a significant improvement in survival, compared with dacarbazine.
"The knowledge that melanomas harbor recurring hot spot mutations in the BRAF gene has rapidly brought molecular testing to the clinical stage," wrote Dr. Jonathan L. Curry of the department of pathology at the University of Texas MD Anderson Cancer Center, Houston, and his colleagues.
The cobas 4800 BRAF V600 Mutation Test from Roche, for example, was approved by the FDA as an in vitro diagnostic device to detect mutant BRAF V600E in DNA extracted from a FFPE patient’s sample of melanoma (Sem. Cut. Med. Surg. 2012;31:268-74). The presence of the mutation aids in selecting patients for treatment with vemurafenib.
The authors noted that a number of molecular platforms for BRAF testing have been developed and continue to evolve, offering a more thorough and complex analysis of the genetic components of melanoma.
"The next generation sequencing or massively parallel sequencing will allow sequencing of the entire exon or whole genome. Multiple sequencing molecular platforms are available to examine for BRAF mutations in cutaneous melanoma, and the best technological approach continues to be developed," they wrote.
Among those they described are:
• Sanger Sequencing. Sanger chain–termination sequencing of amplified DNA by PCR was the method used to sequence the human genome, and the Sanger method of sequencing led to the detection of BRAF mutations in cutaneous melanoma. Sensitivity is high (fewer than 5% of tumor cells are necessary in a given specimen), but use in the clinical setting is limited to BRAF testing. Although it remains the gold standard for gene sequencing, the Sanger method has technical and practical limitations. For example, it takes 18-19 hours to perform the test, other tests are more sensitive, and it cannot detect changes in the chromosomal copy number and the translocations.
• Pyrosequencing. Also known as sequencing by synthesis, pyrosequencing is among the platforms more sensitive than Sanger sequencing. The detection ratio of mutant BRAF V600E to wild type is 1:5 for Sanger sequencing, and 1:50 for pyrosequencing. Its clinical application is to detect the presence or absence of known mutations within a specific segment of DNA of a single nucleotide polymorphism.
"Because mutations in melanoma appear to cluster in the BRAF, NRAS, and KIT genes, this molecular platform has been readily incorporated into the mutational analysis of melanoma," the authors explained, noting that pyrosequencing is a rapid and sensitive test for detection of more common BRAF V600E mutations, as well as other variants. It is limited to the length of the DNA template sequenced, and is prone to errors reading through homopolymer sequences.
• Allele-Specific Real-Time PCR. This molecular platform, also known as the amplification-refractory mutation system, enriches known mutations in clinical samples to increase sensitivity of detection, and is particularly useful in FFPE biopsies with low tumor content. It is highly sensitive and is confined to known BRAF mutations that occur in melanomas, but demonstrates greater sensitivity in detecting BRAF V600E mutations in FFPE clinical samples.
• Mass Spectrometry–Based Sequencing (Sequenom). Sequenom uses mass spectrometry to determine the sequence of the FFPE tissue samples of melanoma. The platform allows for simultaneous amplification of multiple genetic hot spots, allowing for analysis of several known mutations in a single clinical sample. In the authors’ experience, it has slightly higher sensitivity than pyrosequencing.
• High Resolution Melting (HRM). Also a highly sensitive method for screening for mutations in clinical samples, high-resolution melting relies on PCR amplification of the DNA template and analysis of the temperature gradient in which the double strands of the PCR products are melted. The strands melt at different temperatures, depending on the sequence of the constituent bases, allowing for detection of the mutant allele in the FFPE tissue sample. An important limitation of this approach is that specific nucleotide alteration is not reported, thus tissues samples that are positive for mutations will require additional sequencing by another method to determine the specific nucleotide alteration.
• The 454 Pyrosequencing (Roche). This powerful platform, one of several next generation sequencing technologies that allows ultra deep sequencing of entire exons, was used to resolve mutation discrepancies between the cobas 4800 BRAF V600 test and the Sanger sequencing method during the vemurafenib trials, the authors noted. It has a mean error rate of only 1.07%, with more than half of the errors at sites of homopolymers, has the lengths of individual reads of DNA sequences of more than 500 base pairs, and can be performed in less than a day.
• Cobas 4800 BRAF V600 Mutation Test. The cobas 4800 BRAF V600 Mutation Test is based on the principles of allele-specific real time PCR, and targets a predefined 116-base pair sequence of the BRAF gene on exon 15. The device, which is intended to identify those with BRAF V600E who might benefit from therapy with vemurafenib, has a sensitivity for detecting BRAF V600E on FFPE samples of melanoma of more than 99%, and a specificity of 88%. The sensitivity appears comparable with the other platforms, including Sequenom and HRM.
Although the platform is not designed to screen for nonrecurrent genetic mutations in melanoma, BRAF V600E appears to account for the highest percentage of mutations in cutaneous melanomas, the authors said.
Cutaneous Lymphoma Analysis
In cutaneous lymphomas, molecular analysis serves to confirm the diagnosis in cases in which the clinical and/or pathologic presentations do not provide a diagnosis and to further characterize the nature of the lymphoma, according to Dr. Janyana M.D. Deonizio and Dr. Joan Guitart.
While the gold standard for diagnosis is a solid clinicopathologic correlation, molecular analysis provides for a more concrete diagnosis that helps both the patient in facing the diagnosis, and the clinician in proceeding with the most appropriate treatment plan (Sem. Cut. Med. Surg. 2012;31:234-40).
Specifically, through immunophenotyping and clonality analysis, molecular analysis helps discern whether the lymphoma is primarily cutaneous or systemic with secondary skin involvement, and it subclassifies the tumor.
Methods for establishing T-cell clonality include Southern blot analysis (SBA) and PCR for detection of specific T-cell receptor gene arrangements (TCR-GR). SBA used to be the gold standard, but has been gradually replaced by PCR techniques which are less laborious and lengthy. PCR sensitivity for T-cell clonality detection ranges from 70% to 90%.
"Ideally, TCR clonality should be checked at the time of diagnosis in skin and blood. ... The detection of a dominant clone is important not only to confirm diagnosis but also for some prognostic guidance," they wrote, explaining that T-cell cloning is particularly helpful when early-stage mycosis fungoides is being considered in the differential diagnosis.
It does have limitations, however. False-positive monoclonal or oligoclonal bands may be identified in inflammatory dermatoses when T-cell infiltrates are sparse, resulting in "pseudomonoclonality," which is infrequently associated with a malignant T-cell process, they noted.
"Repeating the analysis using the same DNA template or fresh DNA extraction may solve the problem because in reactive conditions, the predominant PCR products typically vary in repeated PCR analyses of the same sample. In contrast, in neoplastic T-cell proliferations, dominant TCR clones are reproducible and should be routinely verified to confirm monoclonality," they noted.
Some studies suggest a correlation between TCR clonality by PCR and response to treatment; the absence of a detectable clone in cutaneous T-cell lymphoma (CTCL) has been associated with a higher rate of complete remission – although not necessarily with improved survival.
Immunophenotypic and immunogenotypic assays have been used to monitor the response of CTCL to therapy, define remission, and detect early relapse, thereby improving assessment of disease activity.
Flow cytometry analysis, for example, is "an efficient and sensitive method to detect and enumerate abnormal cells in the peripheral blood or any other cell suspension," they wrote. It can also be performed on leukocyte suspension from skin biopsies, and it provides prognostic information.
"Lower counts of circulating CD8+ lymphocytes and higher white cell counts in CTCL patients are associated with a less favorable prognosis," the authors noted.
FISH is used to detect major chromosomal gains or losses and specific translocations using a target-specific probe. Although FISH is not routinely used in the diagnosis of cutaneous lymphomas, it does appear to have potential future applications in various areas, according to recent publications.
Finally, genomic analysis by microarray-based comparative genomic hybridization is allowing quantification and appositional defining of chromosomal imbalances. While still confined to the research arena, this technology is providing some insight into the molecular pathogenesis of CTCL, the reported.
The advances in molecular diagnostics that are outlined in this series of articles are not limited to skin cancers and tumors. Additional articles, for example, addressed the role of genetic and molecular analysis in alopecia and in genodermatoses. Together they underscore the need for, and substantiate the ability of the specialty to take on leadership roles in molecular medicine, noted Dr. Gerami, of the department of dermatology at Northwestern University in Chicago.
"I am hopeful that they can assist other practicing dermatologists and dermatopathologists acquire a better foundation in molecular medicine, allowing them to sustain their primary roles in cutaneous medicine," Dr. Gerami concluded.
The authors reported having no conflicts of interest.
To sustain the role of expert in cutaneous medicine, dermatologists and dermatopathologists must embrace the molecular advances in medicine, according to Dr. Pedram Gerami.
"For the vast majority of dermatologists and dermatopathologists trained in traditional clinical medicine, the sheer volume of newly identified gene mutations, chromosomal aberrations, and related molecular tests, even within a focused area of specialization, is truly overwhelming. As in many aspects of life, such rapid and transformative changes may be met with welcome or resistance," wrote Dr. Gerami, who was a guest editor of the December issue of Seminars in Cutaneous Medicine and Surgery, which focused on molecular medicine.
Rather than giving in to the common fear that new technological advancements may replace years of clinical training, it is important to recognize that these advances are meant to supplement – not replace – the clinical expertise of dermatologists and dermatopathologists (Sem. Cut. Med. Surg. 2012;31:203).
"The greatest threat to our practice is not the technologic advancement but rather loss of certain aspects of our practice to other specialties [that] better embrace the molecular revolution," he said, adding that active leadership with respect to integrating molecular medicine into the specialty will have a protective effect.
The first step is gaining a deeper understanding of these rapidly emerging advances. Among them are:
Diagnosis of Cutaneous Soft-Tissue Tumors
The identification of genetic abnormalities that characterize soft-tissue tumors has led to the development of diagnostic molecular testing, according to Dr. Alison L. Cheah and Dr. Steven D. Billings, both of the department of anatomic pathology at the Cleveland Clinic.
"Specific genetic signatures characterize a growing number of soft-tissue tumors that affect the skin. Molecular testing on FFPE [formalin-fixed paraffin-embedded tissue] complements histology and immunohistochemistry in the diagnosis of these tumors, especially in challenging cases with atypical morphology, nonspecific immunophenotype, and/or limited sampling," they wrote.
Molecular diagnostics also has implications for more accurate classification and prognostication of poorly understood entities (Sem. Cut. Med. Surg. 2012;31:221-33). "The identification of these disease-defining genetic signatures is the basis for the development of targeted therapies," they wrote.
Take dermatofibrosarcoma protuberans (DFSP), for example. "In practice, molecular testing in DFSP has utility both as a diagnostic aid in challenging cases and to guide therapy," they explained.
While most cases are easily diagnosed based on histopathologic features, significant diagnostic challenges can arise in certain cases, such as in CD34-negative tumors that are superficially sampled, or in tumors with varying histology or an unusual presentation.
For guiding treatment, molecular testing can be helpful for confirmation of COL1A1-PDGF-beta, which is vital if treatment with imatinib mesylate is being considered, because tumors lacking the fusion gene do not respond to this drug, they noted. Imatinib mesylate recently received Food and Drug Administration approval for the treatment of unresectable metastatic or recurrent DFSP.
Real-time polymerase chain reaction (RT-PCR) is the most studied test for detecting COL1A1-PDGF-beta and has a reported sensitivity between 74% and 96%. Though not as well studied, fluorescence in situ hybridization (FISH) assays also show promise.
"FISH assays using both PDGF-beta break-apart and COL1A1-PDGF-beta dual-color dual-fusion probe techniques have also been used," they wrote, noting that some reports show a greater sensitivity of FISH than RT-PCR for DFSP.
Molecular assays can also be helpful in confirming the diagnosis of angiomatoid fibrous histiocytoma (AFH).
In a study of 17 cases, FISH assays with dual-color break-apart probes had a sensitivity of 76% for identifying EWSR1 and FUS gene rearrangements, regardless of the translocation partner, they noted. FISH results should be interpreted with caution, though, because a negative result does not rule out the diagnosis of AFH, as rearrangements that are not detectable with the particular FISH probes used, or translocations with different chromosomes altogether, could explain a negative FISH result.
"Of note, EWSR1 rearrangements occur in several other soft tissue sarcomas, including Ewing sarcoma family of tumors, desmoplastic small round-cell tumors, clear cell sarcoma, extraskeletal myxoid chondrosarcoma, and a subset of myoepithelial tumors," they noted, adding that correlation with the histologic and immunohistochemical findings remains paramount.
RT-PCR is also a sensitive and specific assay for AFH, but its practical utility is limited by the multiple primers to account for the various fusion transcripts described in AFH.
Another area in which molecular testing plays an important role – albeit complementary– is in the diagnosis of low-grade fibromyxoid sarcoma (LGFMS), they reported. On the basis of RT-PCR results, for example, a significant number of cases previously diagnosed as LGMFS had to be reclassified.
RT-PCR assays performed on FFPE tissues had a sensitivity of 81%-88%, and FISH testing for FUS gene rearrangement is less sensitive at about 70%, but is nonetheless a good alternative to PCR, particularly in paraffin blocks with poor quality RNA.
These are just a few of the areas discussed by Dr. Cheah and Dr. Billings, with respect to molecular testing for cutaneous soft tissue tumors. Others addressed in their article were clear-cell sarcoma (melanoma of the soft parts), postradiation angiosarcoma, epithelioid hemangioendothelioma, and Ewing sarcoma family of tumors.
Knowledge and identification of the recurrent molecular aberrations in these cutaneous mesenchymal tumors allow for more accurate diagnosis and advancement of understanding about their underlying biology.
BRAF V600E Mutation Detection
The identification of BRAF mutations in the mitogen-activated protein kinase pathway revolutionized the treatment of advanced-stage melanoma, bringing selective small-molecule RAF inhibitors, such as vemurafenib, to the clinical trial stage. In the phase III BRIM-3 trial, vemurafenib was associated with a higher response rate and a significant improvement in survival, compared with dacarbazine.
"The knowledge that melanomas harbor recurring hot spot mutations in the BRAF gene has rapidly brought molecular testing to the clinical stage," wrote Dr. Jonathan L. Curry of the department of pathology at the University of Texas MD Anderson Cancer Center, Houston, and his colleagues.
The cobas 4800 BRAF V600 Mutation Test from Roche, for example, was approved by the FDA as an in vitro diagnostic device to detect mutant BRAF V600E in DNA extracted from a FFPE patient’s sample of melanoma (Sem. Cut. Med. Surg. 2012;31:268-74). The presence of the mutation aids in selecting patients for treatment with vemurafenib.
The authors noted that a number of molecular platforms for BRAF testing have been developed and continue to evolve, offering a more thorough and complex analysis of the genetic components of melanoma.
"The next generation sequencing or massively parallel sequencing will allow sequencing of the entire exon or whole genome. Multiple sequencing molecular platforms are available to examine for BRAF mutations in cutaneous melanoma, and the best technological approach continues to be developed," they wrote.
Among those they described are:
• Sanger Sequencing. Sanger chain–termination sequencing of amplified DNA by PCR was the method used to sequence the human genome, and the Sanger method of sequencing led to the detection of BRAF mutations in cutaneous melanoma. Sensitivity is high (fewer than 5% of tumor cells are necessary in a given specimen), but use in the clinical setting is limited to BRAF testing. Although it remains the gold standard for gene sequencing, the Sanger method has technical and practical limitations. For example, it takes 18-19 hours to perform the test, other tests are more sensitive, and it cannot detect changes in the chromosomal copy number and the translocations.
• Pyrosequencing. Also known as sequencing by synthesis, pyrosequencing is among the platforms more sensitive than Sanger sequencing. The detection ratio of mutant BRAF V600E to wild type is 1:5 for Sanger sequencing, and 1:50 for pyrosequencing. Its clinical application is to detect the presence or absence of known mutations within a specific segment of DNA of a single nucleotide polymorphism.
"Because mutations in melanoma appear to cluster in the BRAF, NRAS, and KIT genes, this molecular platform has been readily incorporated into the mutational analysis of melanoma," the authors explained, noting that pyrosequencing is a rapid and sensitive test for detection of more common BRAF V600E mutations, as well as other variants. It is limited to the length of the DNA template sequenced, and is prone to errors reading through homopolymer sequences.
• Allele-Specific Real-Time PCR. This molecular platform, also known as the amplification-refractory mutation system, enriches known mutations in clinical samples to increase sensitivity of detection, and is particularly useful in FFPE biopsies with low tumor content. It is highly sensitive and is confined to known BRAF mutations that occur in melanomas, but demonstrates greater sensitivity in detecting BRAF V600E mutations in FFPE clinical samples.
• Mass Spectrometry–Based Sequencing (Sequenom). Sequenom uses mass spectrometry to determine the sequence of the FFPE tissue samples of melanoma. The platform allows for simultaneous amplification of multiple genetic hot spots, allowing for analysis of several known mutations in a single clinical sample. In the authors’ experience, it has slightly higher sensitivity than pyrosequencing.
• High Resolution Melting (HRM). Also a highly sensitive method for screening for mutations in clinical samples, high-resolution melting relies on PCR amplification of the DNA template and analysis of the temperature gradient in which the double strands of the PCR products are melted. The strands melt at different temperatures, depending on the sequence of the constituent bases, allowing for detection of the mutant allele in the FFPE tissue sample. An important limitation of this approach is that specific nucleotide alteration is not reported, thus tissues samples that are positive for mutations will require additional sequencing by another method to determine the specific nucleotide alteration.
• The 454 Pyrosequencing (Roche). This powerful platform, one of several next generation sequencing technologies that allows ultra deep sequencing of entire exons, was used to resolve mutation discrepancies between the cobas 4800 BRAF V600 test and the Sanger sequencing method during the vemurafenib trials, the authors noted. It has a mean error rate of only 1.07%, with more than half of the errors at sites of homopolymers, has the lengths of individual reads of DNA sequences of more than 500 base pairs, and can be performed in less than a day.
• Cobas 4800 BRAF V600 Mutation Test. The cobas 4800 BRAF V600 Mutation Test is based on the principles of allele-specific real time PCR, and targets a predefined 116-base pair sequence of the BRAF gene on exon 15. The device, which is intended to identify those with BRAF V600E who might benefit from therapy with vemurafenib, has a sensitivity for detecting BRAF V600E on FFPE samples of melanoma of more than 99%, and a specificity of 88%. The sensitivity appears comparable with the other platforms, including Sequenom and HRM.
Although the platform is not designed to screen for nonrecurrent genetic mutations in melanoma, BRAF V600E appears to account for the highest percentage of mutations in cutaneous melanomas, the authors said.
Cutaneous Lymphoma Analysis
In cutaneous lymphomas, molecular analysis serves to confirm the diagnosis in cases in which the clinical and/or pathologic presentations do not provide a diagnosis and to further characterize the nature of the lymphoma, according to Dr. Janyana M.D. Deonizio and Dr. Joan Guitart.
While the gold standard for diagnosis is a solid clinicopathologic correlation, molecular analysis provides for a more concrete diagnosis that helps both the patient in facing the diagnosis, and the clinician in proceeding with the most appropriate treatment plan (Sem. Cut. Med. Surg. 2012;31:234-40).
Specifically, through immunophenotyping and clonality analysis, molecular analysis helps discern whether the lymphoma is primarily cutaneous or systemic with secondary skin involvement, and it subclassifies the tumor.
Methods for establishing T-cell clonality include Southern blot analysis (SBA) and PCR for detection of specific T-cell receptor gene arrangements (TCR-GR). SBA used to be the gold standard, but has been gradually replaced by PCR techniques which are less laborious and lengthy. PCR sensitivity for T-cell clonality detection ranges from 70% to 90%.
"Ideally, TCR clonality should be checked at the time of diagnosis in skin and blood. ... The detection of a dominant clone is important not only to confirm diagnosis but also for some prognostic guidance," they wrote, explaining that T-cell cloning is particularly helpful when early-stage mycosis fungoides is being considered in the differential diagnosis.
It does have limitations, however. False-positive monoclonal or oligoclonal bands may be identified in inflammatory dermatoses when T-cell infiltrates are sparse, resulting in "pseudomonoclonality," which is infrequently associated with a malignant T-cell process, they noted.
"Repeating the analysis using the same DNA template or fresh DNA extraction may solve the problem because in reactive conditions, the predominant PCR products typically vary in repeated PCR analyses of the same sample. In contrast, in neoplastic T-cell proliferations, dominant TCR clones are reproducible and should be routinely verified to confirm monoclonality," they noted.
Some studies suggest a correlation between TCR clonality by PCR and response to treatment; the absence of a detectable clone in cutaneous T-cell lymphoma (CTCL) has been associated with a higher rate of complete remission – although not necessarily with improved survival.
Immunophenotypic and immunogenotypic assays have been used to monitor the response of CTCL to therapy, define remission, and detect early relapse, thereby improving assessment of disease activity.
Flow cytometry analysis, for example, is "an efficient and sensitive method to detect and enumerate abnormal cells in the peripheral blood or any other cell suspension," they wrote. It can also be performed on leukocyte suspension from skin biopsies, and it provides prognostic information.
"Lower counts of circulating CD8+ lymphocytes and higher white cell counts in CTCL patients are associated with a less favorable prognosis," the authors noted.
FISH is used to detect major chromosomal gains or losses and specific translocations using a target-specific probe. Although FISH is not routinely used in the diagnosis of cutaneous lymphomas, it does appear to have potential future applications in various areas, according to recent publications.
Finally, genomic analysis by microarray-based comparative genomic hybridization is allowing quantification and appositional defining of chromosomal imbalances. While still confined to the research arena, this technology is providing some insight into the molecular pathogenesis of CTCL, the reported.
The advances in molecular diagnostics that are outlined in this series of articles are not limited to skin cancers and tumors. Additional articles, for example, addressed the role of genetic and molecular analysis in alopecia and in genodermatoses. Together they underscore the need for, and substantiate the ability of the specialty to take on leadership roles in molecular medicine, noted Dr. Gerami, of the department of dermatology at Northwestern University in Chicago.
"I am hopeful that they can assist other practicing dermatologists and dermatopathologists acquire a better foundation in molecular medicine, allowing them to sustain their primary roles in cutaneous medicine," Dr. Gerami concluded.
The authors reported having no conflicts of interest.
Hereditary Nonmelanoma Skin Cancer
Vasiliki Nikolaou, MD, Alexander J. Stratigos, MD, and Hensin Tsao, MD, PhD
Cutaneous basal and squamous cell carcinomas are among the most frequent malignancies in the white population, with the annual incidence estimates ranging from 1 million to 3.5 million cases in the United States. These tumors can occur either sporadically or in the context of hereditary genodermatoses with cancer predisposition, such as basal cell nevus syndrome, xeroderma pigmentosum, epidermolysis bullosa, or oculocutaneous albinism. Different genes and signaling pathways have been shown to play a central role in the development and growth of these tumors. This article overviews the clinical features, diagnostic criteria, and the most recent data on genetic routes of the major hereditary syndromes predisposed to the development of nonmelanoma skin cancer.
*For a PDF of the full article, click on the link to the left of this introduction.
Vasiliki Nikolaou, MD, Alexander J. Stratigos, MD, and Hensin Tsao, MD, PhD
Cutaneous basal and squamous cell carcinomas are among the most frequent malignancies in the white population, with the annual incidence estimates ranging from 1 million to 3.5 million cases in the United States. These tumors can occur either sporadically or in the context of hereditary genodermatoses with cancer predisposition, such as basal cell nevus syndrome, xeroderma pigmentosum, epidermolysis bullosa, or oculocutaneous albinism. Different genes and signaling pathways have been shown to play a central role in the development and growth of these tumors. This article overviews the clinical features, diagnostic criteria, and the most recent data on genetic routes of the major hereditary syndromes predisposed to the development of nonmelanoma skin cancer.
*For a PDF of the full article, click on the link to the left of this introduction.
Vasiliki Nikolaou, MD, Alexander J. Stratigos, MD, and Hensin Tsao, MD, PhD
Cutaneous basal and squamous cell carcinomas are among the most frequent malignancies in the white population, with the annual incidence estimates ranging from 1 million to 3.5 million cases in the United States. These tumors can occur either sporadically or in the context of hereditary genodermatoses with cancer predisposition, such as basal cell nevus syndrome, xeroderma pigmentosum, epidermolysis bullosa, or oculocutaneous albinism. Different genes and signaling pathways have been shown to play a central role in the development and growth of these tumors. This article overviews the clinical features, diagnostic criteria, and the most recent data on genetic routes of the major hereditary syndromes predisposed to the development of nonmelanoma skin cancer.
*For a PDF of the full article, click on the link to the left of this introduction.
The Role of Molecular Testing in the Diagnosis of Cutaneous Soft Tissue Tumors
Alison L. Cheah, MBBS, and Steven D. Billings, MD
A number of soft tissue tumors are characterized by recurring genetic abnormalities. The identification of these abnormalities has advanced our understanding of the biology of these tumors and has led to the development of molecular tests that are helpful diagnostically. This review will focus on the application of molecular diagnostic testing in select mesenchymal tumors of the dermis and subcutis.
*For a PDF of the full article, click on the link to the left of this introduction.
Alison L. Cheah, MBBS, and Steven D. Billings, MD
A number of soft tissue tumors are characterized by recurring genetic abnormalities. The identification of these abnormalities has advanced our understanding of the biology of these tumors and has led to the development of molecular tests that are helpful diagnostically. This review will focus on the application of molecular diagnostic testing in select mesenchymal tumors of the dermis and subcutis.
*For a PDF of the full article, click on the link to the left of this introduction.
Alison L. Cheah, MBBS, and Steven D. Billings, MD
A number of soft tissue tumors are characterized by recurring genetic abnormalities. The identification of these abnormalities has advanced our understanding of the biology of these tumors and has led to the development of molecular tests that are helpful diagnostically. This review will focus on the application of molecular diagnostic testing in select mesenchymal tumors of the dermis and subcutis.
*For a PDF of the full article, click on the link to the left of this introduction.
The Role of Molecular Analysis in Cutaneous Lymphomas
Janyana M.D. Deonizio, MD, and Joan Guitart, MD
The purpose of this review is to summarize the most important molecular techniques for the diagnosis of cutaneous lymphomas. When making a diagnosis, we are looking for the solid clinicopathological correlation. Molecular analysis includes immunophenotyping and clonality analysis, and is important for 2 principal reasons: (1) to confirm the diagnosis in cases where the clinical and/or pathological presentations are nondiagnostic, and (2) to further characterize the nature of the lymphoma. More specifically, we are trying to discern whether the lymphoma is primarily cutaneous or systemic with secondary skin involvement, and we are also attempting to subclassify the tumor. Recently, many techniques have provided a more accurate diagnosis of cutaneous lymphomas and some prognostic implications, including polymerase chain reaction, fluorescence in situ hybridization, and flow cytometry. Fluorescence in situ hybridization is not routinely used in the diagnosis of cutaneous lymphoma, but many studies have shown potential future applications in various areas. Other techniques, such as comparative genomic hybridization, are still confined to the research arena, but have added some insight into the molecular pathogenesis of cutaneous T-cell lymphoma.
*For a PDF of the full article, click on the link to the left of this introduction.
Janyana M.D. Deonizio, MD, and Joan Guitart, MD
The purpose of this review is to summarize the most important molecular techniques for the diagnosis of cutaneous lymphomas. When making a diagnosis, we are looking for the solid clinicopathological correlation. Molecular analysis includes immunophenotyping and clonality analysis, and is important for 2 principal reasons: (1) to confirm the diagnosis in cases where the clinical and/or pathological presentations are nondiagnostic, and (2) to further characterize the nature of the lymphoma. More specifically, we are trying to discern whether the lymphoma is primarily cutaneous or systemic with secondary skin involvement, and we are also attempting to subclassify the tumor. Recently, many techniques have provided a more accurate diagnosis of cutaneous lymphomas and some prognostic implications, including polymerase chain reaction, fluorescence in situ hybridization, and flow cytometry. Fluorescence in situ hybridization is not routinely used in the diagnosis of cutaneous lymphoma, but many studies have shown potential future applications in various areas. Other techniques, such as comparative genomic hybridization, are still confined to the research arena, but have added some insight into the molecular pathogenesis of cutaneous T-cell lymphoma.
*For a PDF of the full article, click on the link to the left of this introduction.
Janyana M.D. Deonizio, MD, and Joan Guitart, MD
The purpose of this review is to summarize the most important molecular techniques for the diagnosis of cutaneous lymphomas. When making a diagnosis, we are looking for the solid clinicopathological correlation. Molecular analysis includes immunophenotyping and clonality analysis, and is important for 2 principal reasons: (1) to confirm the diagnosis in cases where the clinical and/or pathological presentations are nondiagnostic, and (2) to further characterize the nature of the lymphoma. More specifically, we are trying to discern whether the lymphoma is primarily cutaneous or systemic with secondary skin involvement, and we are also attempting to subclassify the tumor. Recently, many techniques have provided a more accurate diagnosis of cutaneous lymphomas and some prognostic implications, including polymerase chain reaction, fluorescence in situ hybridization, and flow cytometry. Fluorescence in situ hybridization is not routinely used in the diagnosis of cutaneous lymphoma, but many studies have shown potential future applications in various areas. Other techniques, such as comparative genomic hybridization, are still confined to the research arena, but have added some insight into the molecular pathogenesis of cutaneous T-cell lymphoma.
*For a PDF of the full article, click on the link to the left of this introduction.
Molecular Diagnosis of Infection-Related Cancers in Dermatopathology
Melissa Pulitzer, MD
The association between viruses and skin cancer is increasingly recognized in a number of neoplasms, that is, cutaneous squamous cell carcinoma, Kaposi sarcoma, nasopharyngeal carcinoma, and Merkel cell carcinoma, as well as hematolymphoid malignancies such as adult T-cell leukemia/lymphoma and NK/T-cell lymphoma (nasal type) and post-transplant lymphoproliferative disorders. Molecular assays are increasingly used to diagnose and manage these diseases. In this review, molecular features of tumor viruses and related host responses are explored. The tests used to identify such features are summarized. Evaluation of the utility of these assays for diagnosis and/or management of specific tumor types is presented.
*For a PDF of the full article, click on the link to the left of this introduction.
Melissa Pulitzer, MD
The association between viruses and skin cancer is increasingly recognized in a number of neoplasms, that is, cutaneous squamous cell carcinoma, Kaposi sarcoma, nasopharyngeal carcinoma, and Merkel cell carcinoma, as well as hematolymphoid malignancies such as adult T-cell leukemia/lymphoma and NK/T-cell lymphoma (nasal type) and post-transplant lymphoproliferative disorders. Molecular assays are increasingly used to diagnose and manage these diseases. In this review, molecular features of tumor viruses and related host responses are explored. The tests used to identify such features are summarized. Evaluation of the utility of these assays for diagnosis and/or management of specific tumor types is presented.
*For a PDF of the full article, click on the link to the left of this introduction.
Melissa Pulitzer, MD
The association between viruses and skin cancer is increasingly recognized in a number of neoplasms, that is, cutaneous squamous cell carcinoma, Kaposi sarcoma, nasopharyngeal carcinoma, and Merkel cell carcinoma, as well as hematolymphoid malignancies such as adult T-cell leukemia/lymphoma and NK/T-cell lymphoma (nasal type) and post-transplant lymphoproliferative disorders. Molecular assays are increasingly used to diagnose and manage these diseases. In this review, molecular features of tumor viruses and related host responses are explored. The tests used to identify such features are summarized. Evaluation of the utility of these assays for diagnosis and/or management of specific tumor types is presented.
*For a PDF of the full article, click on the link to the left of this introduction.
As human tumor viruses are prevalent, and as virus-driven neoplasms are increasingly identified with advancing technology, it is important to know how to use relevant molecular tests to gain meaningful diagnostic, prognostic, and therapeutic information for individual patients.
Molecular Platforms Utilized to Detect BRAF V600E Mutation in Melanoma
Jonathan L. Curry, MD, Carlos A. Torres-Cabala, MD,Michael T. Tetzlaff, MD, PhD, Christopher Bowman, BS, MT(ASCP)SV, and Victor G. Prieto, MD, PhD
Metastatic melanoma (MM) is a deadly skin disease refractory to standard chemotherapy. Despite numerous clinical and pathological parameters derived to guide patient management, clinical outcomes in melanoma patients remain difficult to predict. There is a critical need to delineate the important biomarkers typical of this disease. These biomarkers will ideally illuminate those key biochemical pathways responsible for the aggressive behavior of melanoma and, in the process, unveil new opportunities for the design of rational therapeutic interventions in high-risk patients. The most common recurring mutation in cutaneous melanoma is the prooncogenic BRAF V600E mutation that drives melanoma cell proliferation. The development of RAF inhibitors targeted against BRAF V600E mutant melanoma cells has revolutionized the treatment of MM. Clinical trials with BRAF inhibitor vemurafenib have shown objective clinical response and improved survival in patients with MM; therefore, knowledge of the molecular signature of melanoma in patients will be important in directing management decisions. Several molecular platforms exist to analyze
the mutation status of melanoma. These include Sanger sequencing, pyrosequencing, allele-specific reverse transcriptase polymerase chain reaction, mass spectrometry base sequencing (Sequenom), high-resolution melting curve analysis, and next-generation sequencing methods using microfluidics technology. The Food and Drug Administration has approved the cobas BRAF V600 Mutation Test developed by Roche to analyze BRAF mutation status in formalin-fixed paraffin-embedded tumor samples. The cobas Mutation Test has been designed specifically to detect BRAF V600E mutations, and the analytic performance of this assay has demonstrated >99% sensitivity in the detection of BRAF V600E mutation when compared with the Sanger sequencing method and confirmed with the next-generation sequencing 454-pyrosequencing technology. The lower limit of detection of the percentage of mutant alleles in a tissue sample for the cobas test is less than 4%-5%. Some cross-reactivity with other variants of mutant BRAF was seen with the cobas V600 platform; however, this clinical test offers highly sensitive reproducible BRAF V600E mutation analysis in formalin-fixed paraffin-embedded tumor samples.
*For a PDF of the full article, click on the link to the left of this introduction.
Jonathan L. Curry, MD, Carlos A. Torres-Cabala, MD,Michael T. Tetzlaff, MD, PhD, Christopher Bowman, BS, MT(ASCP)SV, and Victor G. Prieto, MD, PhD
Metastatic melanoma (MM) is a deadly skin disease refractory to standard chemotherapy. Despite numerous clinical and pathological parameters derived to guide patient management, clinical outcomes in melanoma patients remain difficult to predict. There is a critical need to delineate the important biomarkers typical of this disease. These biomarkers will ideally illuminate those key biochemical pathways responsible for the aggressive behavior of melanoma and, in the process, unveil new opportunities for the design of rational therapeutic interventions in high-risk patients. The most common recurring mutation in cutaneous melanoma is the prooncogenic BRAF V600E mutation that drives melanoma cell proliferation. The development of RAF inhibitors targeted against BRAF V600E mutant melanoma cells has revolutionized the treatment of MM. Clinical trials with BRAF inhibitor vemurafenib have shown objective clinical response and improved survival in patients with MM; therefore, knowledge of the molecular signature of melanoma in patients will be important in directing management decisions. Several molecular platforms exist to analyze
the mutation status of melanoma. These include Sanger sequencing, pyrosequencing, allele-specific reverse transcriptase polymerase chain reaction, mass spectrometry base sequencing (Sequenom), high-resolution melting curve analysis, and next-generation sequencing methods using microfluidics technology. The Food and Drug Administration has approved the cobas BRAF V600 Mutation Test developed by Roche to analyze BRAF mutation status in formalin-fixed paraffin-embedded tumor samples. The cobas Mutation Test has been designed specifically to detect BRAF V600E mutations, and the analytic performance of this assay has demonstrated >99% sensitivity in the detection of BRAF V600E mutation when compared with the Sanger sequencing method and confirmed with the next-generation sequencing 454-pyrosequencing technology. The lower limit of detection of the percentage of mutant alleles in a tissue sample for the cobas test is less than 4%-5%. Some cross-reactivity with other variants of mutant BRAF was seen with the cobas V600 platform; however, this clinical test offers highly sensitive reproducible BRAF V600E mutation analysis in formalin-fixed paraffin-embedded tumor samples.
*For a PDF of the full article, click on the link to the left of this introduction.
Jonathan L. Curry, MD, Carlos A. Torres-Cabala, MD,Michael T. Tetzlaff, MD, PhD, Christopher Bowman, BS, MT(ASCP)SV, and Victor G. Prieto, MD, PhD
Metastatic melanoma (MM) is a deadly skin disease refractory to standard chemotherapy. Despite numerous clinical and pathological parameters derived to guide patient management, clinical outcomes in melanoma patients remain difficult to predict. There is a critical need to delineate the important biomarkers typical of this disease. These biomarkers will ideally illuminate those key biochemical pathways responsible for the aggressive behavior of melanoma and, in the process, unveil new opportunities for the design of rational therapeutic interventions in high-risk patients. The most common recurring mutation in cutaneous melanoma is the prooncogenic BRAF V600E mutation that drives melanoma cell proliferation. The development of RAF inhibitors targeted against BRAF V600E mutant melanoma cells has revolutionized the treatment of MM. Clinical trials with BRAF inhibitor vemurafenib have shown objective clinical response and improved survival in patients with MM; therefore, knowledge of the molecular signature of melanoma in patients will be important in directing management decisions. Several molecular platforms exist to analyze
the mutation status of melanoma. These include Sanger sequencing, pyrosequencing, allele-specific reverse transcriptase polymerase chain reaction, mass spectrometry base sequencing (Sequenom), high-resolution melting curve analysis, and next-generation sequencing methods using microfluidics technology. The Food and Drug Administration has approved the cobas BRAF V600 Mutation Test developed by Roche to analyze BRAF mutation status in formalin-fixed paraffin-embedded tumor samples. The cobas Mutation Test has been designed specifically to detect BRAF V600E mutations, and the analytic performance of this assay has demonstrated >99% sensitivity in the detection of BRAF V600E mutation when compared with the Sanger sequencing method and confirmed with the next-generation sequencing 454-pyrosequencing technology. The lower limit of detection of the percentage of mutant alleles in a tissue sample for the cobas test is less than 4%-5%. Some cross-reactivity with other variants of mutant BRAF was seen with the cobas V600 platform; however, this clinical test offers highly sensitive reproducible BRAF V600E mutation analysis in formalin-fixed paraffin-embedded tumor samples.
*For a PDF of the full article, click on the link to the left of this introduction.
Molecular Diagnostics for Ambiguous Melanocytic Tumors
Hilmy Shahbain, BS, Chelsea Cooper, BA, and Pedram Gerami, MD
Certain subsets of melanocytic neoplasms are difficult to classify because of conflicting histologic features and the existence of a poorly defined intermediate grade of melanocytic tumors. The integration of molecular diagnostic information with a histologic impression may contribute significantly toward improving classification. This review discusses the development of and advances in molecular techniques, including comparative genomic hybridization and fluorescence in situ hybridization (FISH) as diagnostic and prognostic tools for melanocytic neoplasms. Further, we discuss how specific molecular aberrations identified via FISH correlate with certain morphologies in melanocytic neoplasms. We also examine the prognostic value of FISH in intermediate-grade melanocytic tumors, particularly atypical Spitz tumors.
*For a PDF of the full article, click on the link to the left of this introduction.
Hilmy Shahbain, BS, Chelsea Cooper, BA, and Pedram Gerami, MD
Certain subsets of melanocytic neoplasms are difficult to classify because of conflicting histologic features and the existence of a poorly defined intermediate grade of melanocytic tumors. The integration of molecular diagnostic information with a histologic impression may contribute significantly toward improving classification. This review discusses the development of and advances in molecular techniques, including comparative genomic hybridization and fluorescence in situ hybridization (FISH) as diagnostic and prognostic tools for melanocytic neoplasms. Further, we discuss how specific molecular aberrations identified via FISH correlate with certain morphologies in melanocytic neoplasms. We also examine the prognostic value of FISH in intermediate-grade melanocytic tumors, particularly atypical Spitz tumors.
*For a PDF of the full article, click on the link to the left of this introduction.
Hilmy Shahbain, BS, Chelsea Cooper, BA, and Pedram Gerami, MD
Certain subsets of melanocytic neoplasms are difficult to classify because of conflicting histologic features and the existence of a poorly defined intermediate grade of melanocytic tumors. The integration of molecular diagnostic information with a histologic impression may contribute significantly toward improving classification. This review discusses the development of and advances in molecular techniques, including comparative genomic hybridization and fluorescence in situ hybridization (FISH) as diagnostic and prognostic tools for melanocytic neoplasms. Further, we discuss how specific molecular aberrations identified via FISH correlate with certain morphologies in melanocytic neoplasms. We also examine the prognostic value of FISH in intermediate-grade melanocytic tumors, particularly atypical Spitz tumors.
*For a PDF of the full article, click on the link to the left of this introduction.
Broad-Spectrum Moisturizer Effectively Prevents Molecular Reactions to UVA Radiation
There's No Place for 'Dabbling' in Mohs Surgery
SAN DIEGO – If you’re thinking about adding Mohs surgery to your dermatology practice, Dr. Edward Yob recommended that you consider the following question: "Am I willing to commit the time and resources necessary to developing a Mohs practice and do it right?"
Ultimately, your decision "will be based on your experience, how efficient you are, and how interested you are in Mohs surgery," he said at the meeting sponsored by the American Society for Mohs Surgery. "There’s no dabbling in Mohs; you either do it, or you don’t."
He offered the following tips on incorporating Mohs surgery into your existing practice:
• Start small. Allow extra time, be careful in your patient selection, and avoid distractions. "You don’t want to do your first few Mohs cases when you have a very busy general dermatology clinic," advised Dr. Yob, who practices dermatology and Mohs surgery in Tulsa, Okla. "Attention to detail is the key to Mohs surgery."
• Consider the impact on your practice environment. Do you plan to generate Mohs patients from your practice, or will the cases be generated from other referring physicians? What’s your population base, what are the community practice patterns, and what’s the competition like? "Do you have a Mohs surgeon on every other block?" Dr. Yob asked. "And what’s your surgical experience and that of your team? Are you in an area where managed care is going to reimburse you?"
• Be mindful of referral sources. In 1990, when Dr. Yob moved to Oklahoma from Washington, D.C., where he served as an Air Force dermatologist, "there was not a Mohs surgeon on the Eastern side of the state," he recalled. "Primary care physicians are an enormous referral source, especially those who do simple excisions. If they know you’re there to take care of those patients, you’ll build a bond and you’ll have a steady stream of patients to care for."
Dr. Yob emphasized the importance of keeping referring physicians in the loop about the patients they send you. "If another dermatologist sends me a patient and that patient says, ‘While I’m here, do you think you could check out this spot?’ I’ll check with the referring physician first," he explained. "Some of them will say, ‘Take care of whatever the patient needs while they’re there,’ while others will say, ‘Send them back and let me do the biopsy,’ or whatever the case may be. You have to respect that. Ultimately good communication is the key."
Other potential referral sources include colleagues who specialize in the ear, nose, and throat; plastic surgery; general surgery; and ophthalmology. You can also spread the word about your practice by offering to give Mohs-specific lectures to hospital staff or to meetings of church groups or civic groups. In those cases, "emphasize the advantage of Mohs in terms of its high cure rate, the fact that it spares tissue, and the fact that it involves an immediate repair," he said.
• What will your backup support be? If a case becomes troublesome beyond your scope of expertise, can you send the patient to the hospital right away and know that he or she will be taken care of? "What about specialty backup in the form of other Mohs surgeons, or experts in pathology, ENT, plastics, radiation oncology, general surgery, neurosurgery, and urology?" he asked. "You need to be able to take advice from your backups."
• Will you use an in-house tech or a contracted tech? "If you’re only doing Mohs on a limited basis, a contracted tech works pretty well," Dr. Yob said. "How experienced is your tech? How fast are they? Are they eager to learn?"
• Be conservative with patient scheduling. Scheduling patients depends on your volume, how many rooms you have dedicated to Mohs, your surgical experience, and the experience of your team. "If you think one Mohs case will take an hour, schedule the time for 2 hours," Dr. Yob recommended. He takes a complexity-based approach to scheduling in which "1" is a minimally complex case, "2" is a moderately complex case, and "3" is a highly complex case "that is going to take you some time and is going to be tough."
Dr. Yob said that he had no relevant financial conflicts to disclose.
SAN DIEGO – If you’re thinking about adding Mohs surgery to your dermatology practice, Dr. Edward Yob recommended that you consider the following question: "Am I willing to commit the time and resources necessary to developing a Mohs practice and do it right?"
Ultimately, your decision "will be based on your experience, how efficient you are, and how interested you are in Mohs surgery," he said at the meeting sponsored by the American Society for Mohs Surgery. "There’s no dabbling in Mohs; you either do it, or you don’t."
He offered the following tips on incorporating Mohs surgery into your existing practice:
• Start small. Allow extra time, be careful in your patient selection, and avoid distractions. "You don’t want to do your first few Mohs cases when you have a very busy general dermatology clinic," advised Dr. Yob, who practices dermatology and Mohs surgery in Tulsa, Okla. "Attention to detail is the key to Mohs surgery."
• Consider the impact on your practice environment. Do you plan to generate Mohs patients from your practice, or will the cases be generated from other referring physicians? What’s your population base, what are the community practice patterns, and what’s the competition like? "Do you have a Mohs surgeon on every other block?" Dr. Yob asked. "And what’s your surgical experience and that of your team? Are you in an area where managed care is going to reimburse you?"
• Be mindful of referral sources. In 1990, when Dr. Yob moved to Oklahoma from Washington, D.C., where he served as an Air Force dermatologist, "there was not a Mohs surgeon on the Eastern side of the state," he recalled. "Primary care physicians are an enormous referral source, especially those who do simple excisions. If they know you’re there to take care of those patients, you’ll build a bond and you’ll have a steady stream of patients to care for."
Dr. Yob emphasized the importance of keeping referring physicians in the loop about the patients they send you. "If another dermatologist sends me a patient and that patient says, ‘While I’m here, do you think you could check out this spot?’ I’ll check with the referring physician first," he explained. "Some of them will say, ‘Take care of whatever the patient needs while they’re there,’ while others will say, ‘Send them back and let me do the biopsy,’ or whatever the case may be. You have to respect that. Ultimately good communication is the key."
Other potential referral sources include colleagues who specialize in the ear, nose, and throat; plastic surgery; general surgery; and ophthalmology. You can also spread the word about your practice by offering to give Mohs-specific lectures to hospital staff or to meetings of church groups or civic groups. In those cases, "emphasize the advantage of Mohs in terms of its high cure rate, the fact that it spares tissue, and the fact that it involves an immediate repair," he said.
• What will your backup support be? If a case becomes troublesome beyond your scope of expertise, can you send the patient to the hospital right away and know that he or she will be taken care of? "What about specialty backup in the form of other Mohs surgeons, or experts in pathology, ENT, plastics, radiation oncology, general surgery, neurosurgery, and urology?" he asked. "You need to be able to take advice from your backups."
• Will you use an in-house tech or a contracted tech? "If you’re only doing Mohs on a limited basis, a contracted tech works pretty well," Dr. Yob said. "How experienced is your tech? How fast are they? Are they eager to learn?"
• Be conservative with patient scheduling. Scheduling patients depends on your volume, how many rooms you have dedicated to Mohs, your surgical experience, and the experience of your team. "If you think one Mohs case will take an hour, schedule the time for 2 hours," Dr. Yob recommended. He takes a complexity-based approach to scheduling in which "1" is a minimally complex case, "2" is a moderately complex case, and "3" is a highly complex case "that is going to take you some time and is going to be tough."
Dr. Yob said that he had no relevant financial conflicts to disclose.
SAN DIEGO – If you’re thinking about adding Mohs surgery to your dermatology practice, Dr. Edward Yob recommended that you consider the following question: "Am I willing to commit the time and resources necessary to developing a Mohs practice and do it right?"
Ultimately, your decision "will be based on your experience, how efficient you are, and how interested you are in Mohs surgery," he said at the meeting sponsored by the American Society for Mohs Surgery. "There’s no dabbling in Mohs; you either do it, or you don’t."
He offered the following tips on incorporating Mohs surgery into your existing practice:
• Start small. Allow extra time, be careful in your patient selection, and avoid distractions. "You don’t want to do your first few Mohs cases when you have a very busy general dermatology clinic," advised Dr. Yob, who practices dermatology and Mohs surgery in Tulsa, Okla. "Attention to detail is the key to Mohs surgery."
• Consider the impact on your practice environment. Do you plan to generate Mohs patients from your practice, or will the cases be generated from other referring physicians? What’s your population base, what are the community practice patterns, and what’s the competition like? "Do you have a Mohs surgeon on every other block?" Dr. Yob asked. "And what’s your surgical experience and that of your team? Are you in an area where managed care is going to reimburse you?"
• Be mindful of referral sources. In 1990, when Dr. Yob moved to Oklahoma from Washington, D.C., where he served as an Air Force dermatologist, "there was not a Mohs surgeon on the Eastern side of the state," he recalled. "Primary care physicians are an enormous referral source, especially those who do simple excisions. If they know you’re there to take care of those patients, you’ll build a bond and you’ll have a steady stream of patients to care for."
Dr. Yob emphasized the importance of keeping referring physicians in the loop about the patients they send you. "If another dermatologist sends me a patient and that patient says, ‘While I’m here, do you think you could check out this spot?’ I’ll check with the referring physician first," he explained. "Some of them will say, ‘Take care of whatever the patient needs while they’re there,’ while others will say, ‘Send them back and let me do the biopsy,’ or whatever the case may be. You have to respect that. Ultimately good communication is the key."
Other potential referral sources include colleagues who specialize in the ear, nose, and throat; plastic surgery; general surgery; and ophthalmology. You can also spread the word about your practice by offering to give Mohs-specific lectures to hospital staff or to meetings of church groups or civic groups. In those cases, "emphasize the advantage of Mohs in terms of its high cure rate, the fact that it spares tissue, and the fact that it involves an immediate repair," he said.
• What will your backup support be? If a case becomes troublesome beyond your scope of expertise, can you send the patient to the hospital right away and know that he or she will be taken care of? "What about specialty backup in the form of other Mohs surgeons, or experts in pathology, ENT, plastics, radiation oncology, general surgery, neurosurgery, and urology?" he asked. "You need to be able to take advice from your backups."
• Will you use an in-house tech or a contracted tech? "If you’re only doing Mohs on a limited basis, a contracted tech works pretty well," Dr. Yob said. "How experienced is your tech? How fast are they? Are they eager to learn?"
• Be conservative with patient scheduling. Scheduling patients depends on your volume, how many rooms you have dedicated to Mohs, your surgical experience, and the experience of your team. "If you think one Mohs case will take an hour, schedule the time for 2 hours," Dr. Yob recommended. He takes a complexity-based approach to scheduling in which "1" is a minimally complex case, "2" is a moderately complex case, and "3" is a highly complex case "that is going to take you some time and is going to be tough."
Dr. Yob said that he had no relevant financial conflicts to disclose.
EXPERT ANALYSIS FROM A MEETING SPONSORED BY THE AMERICAN SOCIETY FOR MOHS SURGERY
Innovative Methods of UV Protection
One of the main reasons patients with darker skin don't apply sunscreen is because they believe they are at low or no risk for ultraviolet damage, according to the results of a survey that I conducted with Dr. Brooke Jackson and Dr. Chikoti Mibenge.
Our findings were presented in a poster at the American Academy of Dermatology's Summer Academy Meeting in Boston.
The study, conducted by surveying 105 patients in Chicago, revealed that 60% of black patients do not wear sunscreen regularly. Additionally, many darker skinned patients reported not liking the whitish or chalky appearance that sunscreens often leave.
However, sunscreen manufacturers are making more elegant formulations of both chemical and physical blockers that do not leave a whitish hue on darker skin.
Sun protective clothing, hats, parasols or umbrellas, avoiding peak hours of sun intensity, and avoiding tanning are all common methods we recommend to patients to protect themselves. Lesser known methods that we can also recommend to our patients include:
Heliocare
Heliocare tablets contain Polypodium leucotomos extract, a fern native to Central and South America rich in antioxidants which protect against formation of free radicals from UV exposure, particularly UVA. The science is based off of the fact that the fern, which was once aquatic, adapted to life on land and created its own protection from UV rays. The recommended dose is 1 tablet each morning or 2 tablets before intense sun exposure. The effect begins 30 minutes after consumption and is still active 2.5 hours after consumption. Total elimination is estimated to be about 8 hours, but pharmacokinetics for elimination have not been published. Numerous published studies have reported its benefits with regards to UV protection. A head-to-head study of UV protection from heliocare versus other powerful antioxidant supplements would be interesting.
Algae and Coral
At King's College in London, research is being done on the photoprotective effect of coral. In a press release last year, Dr. Paul Long reported that algae living within coral produces a sunscreen-like compound that not only protects the algae and coral from UV damage, but also the fish that feed on the coral. The part the algae play is thought to be part of the shikimate pathway found only in microbes and plants. A sunscreen tablet with this ingredient for human use is in the works.
Strawberries
Strawberries, as well as other darker colored berries, are known to contain polyphenols, which are antioxidants. Researchers in Italy and Spain tested a strawberry extract on cultured human fibroblasts to see if there was a photoprotective effect. They added strawberry extract in different concentrations to all but the control group. They then exposed the samples to a dose of UV light "equivalent to 90 minutes of midday summer sun in the French Riviera," said lead investigator Maurizio Battino. The results demonstrated that strawberry extract, especially at a concentration of 0.5 mg/ml, provided UVA protection. It not only boosted cell survival and viability, but also minimized DNA damage when compared with control cells.
Perhaps there will be topical sunscreens that contain strawberry extract in the future. Other foods high in antioxidants that may have sun protective benefits include:
Colored peppers and yellow squash (high in carotenoids).
Tomatoes and watermelon (high in lycopene).
Dark berries, such as blueberries, acai, blackberries, cranberries (rich in anthocyanin).
Turmeric root (curcumin).
Pomegranate (ellegic acid).
Green and black tea (catechins).
Dark cocoa (flavanols).
Green leafy vegetables, such as spinach and kale (xanthophylls, oxygenated carotenoids).
Fish, such as mackerel, salmon, trout, herring, and sardines (omega 3 fatty acids).
These are not a replacement for the more common methods of sun protection, but they may certainly provide an added benefit.
- Naissan Wesley, M.D.
Do you have questions about treating patients with darker skin? If so, send them to [email protected].
One of the main reasons patients with darker skin don't apply sunscreen is because they believe they are at low or no risk for ultraviolet damage, according to the results of a survey that I conducted with Dr. Brooke Jackson and Dr. Chikoti Mibenge.
Our findings were presented in a poster at the American Academy of Dermatology's Summer Academy Meeting in Boston.
The study, conducted by surveying 105 patients in Chicago, revealed that 60% of black patients do not wear sunscreen regularly. Additionally, many darker skinned patients reported not liking the whitish or chalky appearance that sunscreens often leave.
However, sunscreen manufacturers are making more elegant formulations of both chemical and physical blockers that do not leave a whitish hue on darker skin.
Sun protective clothing, hats, parasols or umbrellas, avoiding peak hours of sun intensity, and avoiding tanning are all common methods we recommend to patients to protect themselves. Lesser known methods that we can also recommend to our patients include:
Heliocare
Heliocare tablets contain Polypodium leucotomos extract, a fern native to Central and South America rich in antioxidants which protect against formation of free radicals from UV exposure, particularly UVA. The science is based off of the fact that the fern, which was once aquatic, adapted to life on land and created its own protection from UV rays. The recommended dose is 1 tablet each morning or 2 tablets before intense sun exposure. The effect begins 30 minutes after consumption and is still active 2.5 hours after consumption. Total elimination is estimated to be about 8 hours, but pharmacokinetics for elimination have not been published. Numerous published studies have reported its benefits with regards to UV protection. A head-to-head study of UV protection from heliocare versus other powerful antioxidant supplements would be interesting.
Algae and Coral
At King's College in London, research is being done on the photoprotective effect of coral. In a press release last year, Dr. Paul Long reported that algae living within coral produces a sunscreen-like compound that not only protects the algae and coral from UV damage, but also the fish that feed on the coral. The part the algae play is thought to be part of the shikimate pathway found only in microbes and plants. A sunscreen tablet with this ingredient for human use is in the works.
Strawberries
Strawberries, as well as other darker colored berries, are known to contain polyphenols, which are antioxidants. Researchers in Italy and Spain tested a strawberry extract on cultured human fibroblasts to see if there was a photoprotective effect. They added strawberry extract in different concentrations to all but the control group. They then exposed the samples to a dose of UV light "equivalent to 90 minutes of midday summer sun in the French Riviera," said lead investigator Maurizio Battino. The results demonstrated that strawberry extract, especially at a concentration of 0.5 mg/ml, provided UVA protection. It not only boosted cell survival and viability, but also minimized DNA damage when compared with control cells.
Perhaps there will be topical sunscreens that contain strawberry extract in the future. Other foods high in antioxidants that may have sun protective benefits include:
Colored peppers and yellow squash (high in carotenoids).
Tomatoes and watermelon (high in lycopene).
Dark berries, such as blueberries, acai, blackberries, cranberries (rich in anthocyanin).
Turmeric root (curcumin).
Pomegranate (ellegic acid).
Green and black tea (catechins).
Dark cocoa (flavanols).
Green leafy vegetables, such as spinach and kale (xanthophylls, oxygenated carotenoids).
Fish, such as mackerel, salmon, trout, herring, and sardines (omega 3 fatty acids).
These are not a replacement for the more common methods of sun protection, but they may certainly provide an added benefit.
- Naissan Wesley, M.D.
Do you have questions about treating patients with darker skin? If so, send them to [email protected].
One of the main reasons patients with darker skin don't apply sunscreen is because they believe they are at low or no risk for ultraviolet damage, according to the results of a survey that I conducted with Dr. Brooke Jackson and Dr. Chikoti Mibenge.
Our findings were presented in a poster at the American Academy of Dermatology's Summer Academy Meeting in Boston.
The study, conducted by surveying 105 patients in Chicago, revealed that 60% of black patients do not wear sunscreen regularly. Additionally, many darker skinned patients reported not liking the whitish or chalky appearance that sunscreens often leave.
However, sunscreen manufacturers are making more elegant formulations of both chemical and physical blockers that do not leave a whitish hue on darker skin.
Sun protective clothing, hats, parasols or umbrellas, avoiding peak hours of sun intensity, and avoiding tanning are all common methods we recommend to patients to protect themselves. Lesser known methods that we can also recommend to our patients include:
Heliocare
Heliocare tablets contain Polypodium leucotomos extract, a fern native to Central and South America rich in antioxidants which protect against formation of free radicals from UV exposure, particularly UVA. The science is based off of the fact that the fern, which was once aquatic, adapted to life on land and created its own protection from UV rays. The recommended dose is 1 tablet each morning or 2 tablets before intense sun exposure. The effect begins 30 minutes after consumption and is still active 2.5 hours after consumption. Total elimination is estimated to be about 8 hours, but pharmacokinetics for elimination have not been published. Numerous published studies have reported its benefits with regards to UV protection. A head-to-head study of UV protection from heliocare versus other powerful antioxidant supplements would be interesting.
Algae and Coral
At King's College in London, research is being done on the photoprotective effect of coral. In a press release last year, Dr. Paul Long reported that algae living within coral produces a sunscreen-like compound that not only protects the algae and coral from UV damage, but also the fish that feed on the coral. The part the algae play is thought to be part of the shikimate pathway found only in microbes and plants. A sunscreen tablet with this ingredient for human use is in the works.
Strawberries
Strawberries, as well as other darker colored berries, are known to contain polyphenols, which are antioxidants. Researchers in Italy and Spain tested a strawberry extract on cultured human fibroblasts to see if there was a photoprotective effect. They added strawberry extract in different concentrations to all but the control group. They then exposed the samples to a dose of UV light "equivalent to 90 minutes of midday summer sun in the French Riviera," said lead investigator Maurizio Battino. The results demonstrated that strawberry extract, especially at a concentration of 0.5 mg/ml, provided UVA protection. It not only boosted cell survival and viability, but also minimized DNA damage when compared with control cells.
Perhaps there will be topical sunscreens that contain strawberry extract in the future. Other foods high in antioxidants that may have sun protective benefits include:
Colored peppers and yellow squash (high in carotenoids).
Tomatoes and watermelon (high in lycopene).
Dark berries, such as blueberries, acai, blackberries, cranberries (rich in anthocyanin).
Turmeric root (curcumin).
Pomegranate (ellegic acid).
Green and black tea (catechins).
Dark cocoa (flavanols).
Green leafy vegetables, such as spinach and kale (xanthophylls, oxygenated carotenoids).
Fish, such as mackerel, salmon, trout, herring, and sardines (omega 3 fatty acids).
These are not a replacement for the more common methods of sun protection, but they may certainly provide an added benefit.
- Naissan Wesley, M.D.
Do you have questions about treating patients with darker skin? If so, send them to [email protected].