Tape Test Helps Distinguish Melanoma From Atypical Nevi

SAN DIEGO — Melanoma proved genetically distinguishable from atypical nevi when cells were collected from the stratum corneum using a custom-designed adhesive tape in a poster presentation at the annual meeting of the American Association for Cancer Research.

Molecular analysis of tape-collected RNA identified an expression pattern of 20 genes that was 100% sensitive, 90.6% specific, and 92.4% accurate in detecting both in situ and invasive melanoma in 66 skin samples, reported Dr. William Wachsman of the oncology/hematology division of the University of California, San Diego.

If confirmed in further studies, the technique could be used to obtain a skin sample “noninvasively and painlessly” and to receive an objective diagnosis based on a validated genetic biomarker. “This technique could become the preferred first line for evaluating pigmented lesions suspicious for melanoma,” Dr. Wachsman said in an interview.

The 20-gene cluster used to develop the Epidermal Genetic Information Retrieval (EGIR) system (DermTech International) was selected from an original array of 350 differentially expressed genes put to the test in a preliminary comparison of 18 lesions that proved to be melanoma and 18 ultimately diagnosed as atypical nevi.

In both the preliminary study and the 66-sample testing set, suspicious pigmented lesions and normal skin regions were tape stripped four times using EGIR-specific adhesive film designed by DermTech scientists. Total RNA was then isolated from the tape strips and amplified using microarray technology.

The resulting pattern analysis could distinguish melanomas from normal skin samples as well as from atypical nevi. Furthermore, at least three distinctive groups of atypical nevi were discernable, suggesting the potential of characterizing low- and high-grade nevi.

The finding could have significant diagnostic implications, reducing the number of unnecessary skin biopsies and taking some of the guesswork out of melanoma identification, said Dr. Harold Rabinovitz, a coauthor on the study and a dermatologist in private practice in Plantation, Fla.

Currently, dermatologists can distinguish melanoma from an atypical nevi with about 60% accuracy. The levels of sensitivity and specificity obtained in the study, 100% and 90.6%, respectively, are “very, very high, and exciting,” Dr. Rabinowitz said in an interview.

“The plan is for the RNA samples obtained via EGIR-based tape stripping to be sent to a CLIA [Clinical Laboratory Improvement Amendments] lab for testing. In 3–5 days, the physician will receive a report back that, based on genetic profiling, shows the probability of the lesion in question being a melanoma,” he said.

The company plans to develop a point-of-care application of the technology, so that results would be available while the patient waits in the physician's office.

Dr. Wachsman is an uncompensated adviser to DermTech. Dr. Rabinovitz disclosed that he is a consultant, independent contractor, and advisory board member for DermTech. He also serves as a consultant, medical coordinator, and/or clinical investigator for other technologies aimed at melanoma diagnosis. The first author on the study was Dr. Sherman Chang, director of molecular biology for DermTech in San Diego.

SAN DIEGO — Melanoma proved genetically distinguishable from atypical nevi when cells were collected from the stratum corneum using a custom-designed adhesive tape in a poster presentation at the annual meeting of the American Association for Cancer Research.

Molecular analysis of tape-collected RNA identified an expression pattern of 20 genes that was 100% sensitive, 90.6% specific, and 92.4% accurate in detecting both in situ and invasive melanoma in 66 skin samples, reported Dr. William Wachsman of the oncology/hematology division of the University of California, San Diego.

If confirmed in further studies, the technique could be used to obtain a skin sample “noninvasively and painlessly” and to receive an objective diagnosis based on a validated genetic biomarker. “This technique could become the preferred first line for evaluating pigmented lesions suspicious for melanoma,” Dr. Wachsman said in an interview.

The 20-gene cluster used to develop the Epidermal Genetic Information Retrieval (EGIR) system (DermTech International) was selected from an original array of 350 differentially expressed genes put to the test in a preliminary comparison of 18 lesions that proved to be melanoma and 18 ultimately diagnosed as atypical nevi.

In both the preliminary study and the 66-sample testing set, suspicious pigmented lesions and normal skin regions were tape stripped four times using EGIR-specific adhesive film designed by DermTech scientists. Total RNA was then isolated from the tape strips and amplified using microarray technology.

The resulting pattern analysis could distinguish melanomas from normal skin samples as well as from atypical nevi. Furthermore, at least three distinctive groups of atypical nevi were discernable, suggesting the potential of characterizing low- and high-grade nevi.

The finding could have significant diagnostic implications, reducing the number of unnecessary skin biopsies and taking some of the guesswork out of melanoma identification, said Dr. Harold Rabinovitz, a coauthor on the study and a dermatologist in private practice in Plantation, Fla.

Currently, dermatologists can distinguish melanoma from an atypical nevi with about 60% accuracy. The levels of sensitivity and specificity obtained in the study, 100% and 90.6%, respectively, are “very, very high, and exciting,” Dr. Rabinowitz said in an interview.

“The plan is for the RNA samples obtained via EGIR-based tape stripping to be sent to a CLIA [Clinical Laboratory Improvement Amendments] lab for testing. In 3–5 days, the physician will receive a report back that, based on genetic profiling, shows the probability of the lesion in question being a melanoma,” he said.

The company plans to develop a point-of-care application of the technology, so that results would be available while the patient waits in the physician's office.

Dr. Wachsman is an uncompensated adviser to DermTech. Dr. Rabinovitz disclosed that he is a consultant, independent contractor, and advisory board member for DermTech. He also serves as a consultant, medical coordinator, and/or clinical investigator for other technologies aimed at melanoma diagnosis. The first author on the study was Dr. Sherman Chang, director of molecular biology for DermTech in San Diego.

SAN DIEGO — Melanoma proved genetically distinguishable from atypical nevi when cells were collected from the stratum corneum using a custom-designed adhesive tape in a poster presentation at the annual meeting of the American Association for Cancer Research.

Molecular analysis of tape-collected RNA identified an expression pattern of 20 genes that was 100% sensitive, 90.6% specific, and 92.4% accurate in detecting both in situ and invasive melanoma in 66 skin samples, reported Dr. William Wachsman of the oncology/hematology division of the University of California, San Diego.

If confirmed in further studies, the technique could be used to obtain a skin sample “noninvasively and painlessly” and to receive an objective diagnosis based on a validated genetic biomarker. “This technique could become the preferred first line for evaluating pigmented lesions suspicious for melanoma,” Dr. Wachsman said in an interview.

The 20-gene cluster used to develop the Epidermal Genetic Information Retrieval (EGIR) system (DermTech International) was selected from an original array of 350 differentially expressed genes put to the test in a preliminary comparison of 18 lesions that proved to be melanoma and 18 ultimately diagnosed as atypical nevi.

In both the preliminary study and the 66-sample testing set, suspicious pigmented lesions and normal skin regions were tape stripped four times using EGIR-specific adhesive film designed by DermTech scientists. Total RNA was then isolated from the tape strips and amplified using microarray technology.

The resulting pattern analysis could distinguish melanomas from normal skin samples as well as from atypical nevi. Furthermore, at least three distinctive groups of atypical nevi were discernable, suggesting the potential of characterizing low- and high-grade nevi.

The finding could have significant diagnostic implications, reducing the number of unnecessary skin biopsies and taking some of the guesswork out of melanoma identification, said Dr. Harold Rabinovitz, a coauthor on the study and a dermatologist in private practice in Plantation, Fla.

Currently, dermatologists can distinguish melanoma from an atypical nevi with about 60% accuracy. The levels of sensitivity and specificity obtained in the study, 100% and 90.6%, respectively, are “very, very high, and exciting,” Dr. Rabinowitz said in an interview.

“The plan is for the RNA samples obtained via EGIR-based tape stripping to be sent to a CLIA [Clinical Laboratory Improvement Amendments] lab for testing. In 3–5 days, the physician will receive a report back that, based on genetic profiling, shows the probability of the lesion in question being a melanoma,” he said.

The company plans to develop a point-of-care application of the technology, so that results would be available while the patient waits in the physician's office.

Dr. Wachsman is an uncompensated adviser to DermTech. Dr. Rabinovitz disclosed that he is a consultant, independent contractor, and advisory board member for DermTech. He also serves as a consultant, medical coordinator, and/or clinical investigator for other technologies aimed at melanoma diagnosis. The first author on the study was Dr. Sherman Chang, director of molecular biology for DermTech in San Diego.