NSCLC

Bronchioalveolar cell carcinoma (BAC) is a variant of non–small cell lung cancer (NSCLC) that, in recent years, has received a new identity in some of the literature. Adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) are relatively new entities that in some published literature have replaced the term BAC. The National Comprehensive Cancer Network recognizes these terms. AIS is defined as a localized adenocarcinoma of < 3 cm that exhibits a lepidic growth pattern, with neoplastic cells along the alveolar structures but without stromal, vascular, or pleural invasion. MIA refers to small, solitary adenocarcinomas < 3 cm with either pure lepidic growth or predominant lepidic growth with ≤ 5 mm of stromal invasion. BAC has unique epidemiologic, pathologic, and clinical features compared with other NSCLC subtypes. For example, although it is smoking-related, the relationship of BAC to smoking is less strong than with other types of NSCLC. About a third of patients with BAC are never-smokers. 

There are also some unique radiographic features — its presentation may be confused with pneumonia or other inflammatory conditions in the lung, and only after a patient does not improve after a course of antibiotics should a diagnosis of BAC be considered. Unlike other types of lung cancer where chemotherapy may be the first plan of attack, surgery is often the first choice for treating BAC, particularly when there is no mediastinal node involvement (10%-25% of cases) or distal metastases (5% of cases). BAC usually harbors EGFR mutation. It is responsive to new targeted therapies for lung cancer, particularly osimertinib, afatinib, erlotinib, and gefitinib. Thus, people with BAC are good candidates for genetic testing.

Karl J. D'Silva, MD, Clinical Assistant Professor, Department of Medicine, Tufts University School of Medicine, Boston; Medical Director, Department of Oncology and Hematology, Lahey Hospital and Medical Center, Peabody, Massachusetts

Karl J. D'Silva, MD, has disclosed no relevant financial relationships.

Bronchioalveolar cell carcinoma (BAC) is a variant of non–small cell lung cancer (NSCLC) that, in recent years, has received a new identity in some of the literature. Adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) are relatively new entities that in some published literature have replaced the term BAC. The National Comprehensive Cancer Network recognizes these terms. AIS is defined as a localized adenocarcinoma of < 3 cm that exhibits a lepidic growth pattern, with neoplastic cells along the alveolar structures but without stromal, vascular, or pleural invasion. MIA refers to small, solitary adenocarcinomas < 3 cm with either pure lepidic growth or predominant lepidic growth with ≤ 5 mm of stromal invasion. BAC has unique epidemiologic, pathologic, and clinical features compared with other NSCLC subtypes. For example, although it is smoking-related, the relationship of BAC to smoking is less strong than with other types of NSCLC. About a third of patients with BAC are never-smokers. 

There are also some unique radiographic features — its presentation may be confused with pneumonia or other inflammatory conditions in the lung, and only after a patient does not improve after a course of antibiotics should a diagnosis of BAC be considered. Unlike other types of lung cancer where chemotherapy may be the first plan of attack, surgery is often the first choice for treating BAC, particularly when there is no mediastinal node involvement (10%-25% of cases) or distal metastases (5% of cases). BAC usually harbors EGFR mutation. It is responsive to new targeted therapies for lung cancer, particularly osimertinib, afatinib, erlotinib, and gefitinib. Thus, people with BAC are good candidates for genetic testing.

Karl J. D'Silva, MD, Clinical Assistant Professor, Department of Medicine, Tufts University School of Medicine, Boston; Medical Director, Department of Oncology and Hematology, Lahey Hospital and Medical Center, Peabody, Massachusetts

Karl J. D'Silva, MD, has disclosed no relevant financial relationships.

Bronchioalveolar cell carcinoma (BAC) is a variant of non–small cell lung cancer (NSCLC) that, in recent years, has received a new identity in some of the literature. Adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) are relatively new entities that in some published literature have replaced the term BAC. The National Comprehensive Cancer Network recognizes these terms. AIS is defined as a localized adenocarcinoma of < 3 cm that exhibits a lepidic growth pattern, with neoplastic cells along the alveolar structures but without stromal, vascular, or pleural invasion. MIA refers to small, solitary adenocarcinomas < 3 cm with either pure lepidic growth or predominant lepidic growth with ≤ 5 mm of stromal invasion. BAC has unique epidemiologic, pathologic, and clinical features compared with other NSCLC subtypes. For example, although it is smoking-related, the relationship of BAC to smoking is less strong than with other types of NSCLC. About a third of patients with BAC are never-smokers. 

There are also some unique radiographic features — its presentation may be confused with pneumonia or other inflammatory conditions in the lung, and only after a patient does not improve after a course of antibiotics should a diagnosis of BAC be considered. Unlike other types of lung cancer where chemotherapy may be the first plan of attack, surgery is often the first choice for treating BAC, particularly when there is no mediastinal node involvement (10%-25% of cases) or distal metastases (5% of cases). BAC usually harbors EGFR mutation. It is responsive to new targeted therapies for lung cancer, particularly osimertinib, afatinib, erlotinib, and gefitinib. Thus, people with BAC are good candidates for genetic testing.

Karl J. D'Silva, MD, Clinical Assistant Professor, Department of Medicine, Tufts University School of Medicine, Boston; Medical Director, Department of Oncology and Hematology, Lahey Hospital and Medical Center, Peabody, Massachusetts

Karl J. D'Silva, MD, has disclosed no relevant financial relationships.

On the basis of this presentation, and the findings from the chest x-ray (as shown), the likely diagnosis is non–small cell lung cancer (NSCLC), Pancoast tumor, also known as superior sulcus tumor. Pancoast tumors are rare, representing about 3%-5% of all lung cancers, and invade the structures in the apex of the chest, including the first thoracic ribs or periosteum, the lower nerve roots of the bronchial plexus, the sympathetic chain and stellate ganglion, or the subclavian vessels. The majority of Pancoast tumors are non–small cell carcinomas.

Because of their pulmonary location, Pancoast tumors are characterized by several distinct symptoms. As seen in this case, patients often present with shoulder pain that worsens over time, especially with invasion of the chest wall and brachial plexus. The pain may radiate to the neck; axilla; anterior chest wall; and medial aspect of the arm, forearm, and wrist. If Pancoast tumors infiltrate the ulnar nerve, patients may present with weakness and muscle atrophy of the intrinsic muscles of the hand. In addition, invasion of the sympathetic chain and of the inferior cervical ganglion can cause Horner syndrome (ptosis, miosis, enophthalmos, and anhidrosis). Lastly, upper-arm edema may develop, signaling invasion and potentially occlusion of the subclavian vein.

During workup, CT-guided core biopsy is the first-line diagnostic test for Pancoast tumors. CT of the chest can confirm the presence of an apical mass and its position in relation to other structures of the thoracic inlet. MRI can further assess suspected brachial plexus, subclavian vessels, spine, and neural foramina invasion, specifying the extent of the disease and of the amount of nerve-root involvement.

For resectable Pancoast tumors, the National Comprehensive Cancer Network recommends chemoradiation, followed by surgical resection and chemotherapy. Preoperative chemoradiation together with surgical resection has shown a 2-year survival between 50% and 70%. Depending on biomarker status (certain EGFR mutations or programmed death ligand 1 levels ≥ 1%), the addition of either atezolizumab or osimertinib is advised. However, the positioning of Pancoast tumors can pose a surgical challenge, and if the lesion remains unresectable after preoperative concurrent chemoradiation, then consolidation immunotherapy with durvalumab is recommended.

Karl J. D'Silva, MD, Clinical Assistant Professor, Department of Medicine, Tufts University School of Medicine, Boston; Medical Director, Department of Oncology and Hematology, Lahey Hospital and Medical Center, Peabody, Massachusetts.

Karl J. D'Silva, MD, has disclosed no relevant financial relationships.

Image Quizzes are fictional or fictionalized clinical scenarios intended to provide evidence-based educational takeaways.

On the basis of this presentation, and the findings from the chest x-ray (as shown), the likely diagnosis is non–small cell lung cancer (NSCLC), Pancoast tumor, also known as superior sulcus tumor. Pancoast tumors are rare, representing about 3%-5% of all lung cancers, and invade the structures in the apex of the chest, including the first thoracic ribs or periosteum, the lower nerve roots of the bronchial plexus, the sympathetic chain and stellate ganglion, or the subclavian vessels. The majority of Pancoast tumors are non–small cell carcinomas.

Because of their pulmonary location, Pancoast tumors are characterized by several distinct symptoms. As seen in this case, patients often present with shoulder pain that worsens over time, especially with invasion of the chest wall and brachial plexus. The pain may radiate to the neck; axilla; anterior chest wall; and medial aspect of the arm, forearm, and wrist. If Pancoast tumors infiltrate the ulnar nerve, patients may present with weakness and muscle atrophy of the intrinsic muscles of the hand. In addition, invasion of the sympathetic chain and of the inferior cervical ganglion can cause Horner syndrome (ptosis, miosis, enophthalmos, and anhidrosis). Lastly, upper-arm edema may develop, signaling invasion and potentially occlusion of the subclavian vein.

During workup, CT-guided core biopsy is the first-line diagnostic test for Pancoast tumors. CT of the chest can confirm the presence of an apical mass and its position in relation to other structures of the thoracic inlet. MRI can further assess suspected brachial plexus, subclavian vessels, spine, and neural foramina invasion, specifying the extent of the disease and of the amount of nerve-root involvement.

For resectable Pancoast tumors, the National Comprehensive Cancer Network recommends chemoradiation, followed by surgical resection and chemotherapy. Preoperative chemoradiation together with surgical resection has shown a 2-year survival between 50% and 70%. Depending on biomarker status (certain EGFR mutations or programmed death ligand 1 levels ≥ 1%), the addition of either atezolizumab or osimertinib is advised. However, the positioning of Pancoast tumors can pose a surgical challenge, and if the lesion remains unresectable after preoperative concurrent chemoradiation, then consolidation immunotherapy with durvalumab is recommended.

Karl J. D'Silva, MD, Clinical Assistant Professor, Department of Medicine, Tufts University School of Medicine, Boston; Medical Director, Department of Oncology and Hematology, Lahey Hospital and Medical Center, Peabody, Massachusetts.

Karl J. D'Silva, MD, has disclosed no relevant financial relationships.

Image Quizzes are fictional or fictionalized clinical scenarios intended to provide evidence-based educational takeaways.

On the basis of this presentation, and the findings from the chest x-ray (as shown), the likely diagnosis is non–small cell lung cancer (NSCLC), Pancoast tumor, also known as superior sulcus tumor. Pancoast tumors are rare, representing about 3%-5% of all lung cancers, and invade the structures in the apex of the chest, including the first thoracic ribs or periosteum, the lower nerve roots of the bronchial plexus, the sympathetic chain and stellate ganglion, or the subclavian vessels. The majority of Pancoast tumors are non–small cell carcinomas.

Because of their pulmonary location, Pancoast tumors are characterized by several distinct symptoms. As seen in this case, patients often present with shoulder pain that worsens over time, especially with invasion of the chest wall and brachial plexus. The pain may radiate to the neck; axilla; anterior chest wall; and medial aspect of the arm, forearm, and wrist. If Pancoast tumors infiltrate the ulnar nerve, patients may present with weakness and muscle atrophy of the intrinsic muscles of the hand. In addition, invasion of the sympathetic chain and of the inferior cervical ganglion can cause Horner syndrome (ptosis, miosis, enophthalmos, and anhidrosis). Lastly, upper-arm edema may develop, signaling invasion and potentially occlusion of the subclavian vein.

During workup, CT-guided core biopsy is the first-line diagnostic test for Pancoast tumors. CT of the chest can confirm the presence of an apical mass and its position in relation to other structures of the thoracic inlet. MRI can further assess suspected brachial plexus, subclavian vessels, spine, and neural foramina invasion, specifying the extent of the disease and of the amount of nerve-root involvement.

For resectable Pancoast tumors, the National Comprehensive Cancer Network recommends chemoradiation, followed by surgical resection and chemotherapy. Preoperative chemoradiation together with surgical resection has shown a 2-year survival between 50% and 70%. Depending on biomarker status (certain EGFR mutations or programmed death ligand 1 levels ≥ 1%), the addition of either atezolizumab or osimertinib is advised. However, the positioning of Pancoast tumors can pose a surgical challenge, and if the lesion remains unresectable after preoperative concurrent chemoradiation, then consolidation immunotherapy with durvalumab is recommended.

Karl J. D'Silva, MD, Clinical Assistant Professor, Department of Medicine, Tufts University School of Medicine, Boston; Medical Director, Department of Oncology and Hematology, Lahey Hospital and Medical Center, Peabody, Massachusetts.

Karl J. D'Silva, MD, has disclosed no relevant financial relationships.

Image Quizzes are fictional or fictionalized clinical scenarios intended to provide evidence-based educational takeaways.

Based on the patient's presentation and workup, the likely diagnosis is adenosquamous carcinoma of the lung, a relatively rare subtype of non–small cell lung cancer (NSCLC). Adenosquamous carcinoma displays qualities of both squamous cell carcinoma and adenocarcinoma; for definitive diagnosis, the cancer must contain 10% of each of these major NSCLC subtypes. Maeda and colleagues concluded that adenosquamous carcinoma occurs more frequently among men and that the age at the time of diagnosis is higher among such cancers compared with adenocarcinoma. Several studies have confirmed that adenosquamous carcinoma of the lung is also more prevalent among smokers. 

Though a diagnosis of adenosquamous carcinoma may be suspected after small biopsies, cytology, or excisional biopsies, definitive diagnosis necessitates a resection specimen. If any adenocarcinoma component is observed in a biopsy specimen that is otherwise squamous, as in the present case, this finding is an indication for molecular testing. Epidermal growth factor receptor (EGFR) mutations may be present in adenosquamous carcinoma cancers, despite a majority of cancers with EGFR mutations being among nonsmokers or former light smokers with adenocarcinoma histology. In addition, even for patients diagnosed with squamous cell carcinoma, adenosquamous carcinoma should be considered if genetic testing suggests EGFR mutations.

Relative to adenocarcinoma and squamous cell carcinoma, adenosquamous carcinoma has higher grade malignancy, more advanced postoperative stage, and stronger lymph nodal invasiveness. In terms of treatment, surgical resection is the curative option for adenosquamous carcinoma of the lung, with lobectomy with lymphadenectomy considered for first-line treatment. Though the most beneficial chemotherapy regimen for patients with adenosquamous carcinoma of the lung remains the subject of investigation, platinum-based doublet chemotherapy is the current standard treatment option. EGFR tyrosine kinase inhibitors may be an effective option for EGFR-positive patients. 

Karl J. D'Silva, MD, Clinical Assistant Professor, Department of Medicine, Tufts University School of Medicine, Boston; Medical Director, Department of Oncology and Hematology, Lahey Hospital and Medical Center, Peabody, Massachusetts.

Karl J. D'Silva, MD, has disclosed no relevant financial relationships.

Image Quizzes are fictional or fictionalized clinical scenarios intended to provide evidence-based educational takeaways.

Based on the patient's presentation and workup, the likely diagnosis is adenosquamous carcinoma of the lung, a relatively rare subtype of non–small cell lung cancer (NSCLC). Adenosquamous carcinoma displays qualities of both squamous cell carcinoma and adenocarcinoma; for definitive diagnosis, the cancer must contain 10% of each of these major NSCLC subtypes. Maeda and colleagues concluded that adenosquamous carcinoma occurs more frequently among men and that the age at the time of diagnosis is higher among such cancers compared with adenocarcinoma. Several studies have confirmed that adenosquamous carcinoma of the lung is also more prevalent among smokers. 

Though a diagnosis of adenosquamous carcinoma may be suspected after small biopsies, cytology, or excisional biopsies, definitive diagnosis necessitates a resection specimen. If any adenocarcinoma component is observed in a biopsy specimen that is otherwise squamous, as in the present case, this finding is an indication for molecular testing. Epidermal growth factor receptor (EGFR) mutations may be present in adenosquamous carcinoma cancers, despite a majority of cancers with EGFR mutations being among nonsmokers or former light smokers with adenocarcinoma histology. In addition, even for patients diagnosed with squamous cell carcinoma, adenosquamous carcinoma should be considered if genetic testing suggests EGFR mutations.

Relative to adenocarcinoma and squamous cell carcinoma, adenosquamous carcinoma has higher grade malignancy, more advanced postoperative stage, and stronger lymph nodal invasiveness. In terms of treatment, surgical resection is the curative option for adenosquamous carcinoma of the lung, with lobectomy with lymphadenectomy considered for first-line treatment. Though the most beneficial chemotherapy regimen for patients with adenosquamous carcinoma of the lung remains the subject of investigation, platinum-based doublet chemotherapy is the current standard treatment option. EGFR tyrosine kinase inhibitors may be an effective option for EGFR-positive patients. 

Karl J. D'Silva, MD, Clinical Assistant Professor, Department of Medicine, Tufts University School of Medicine, Boston; Medical Director, Department of Oncology and Hematology, Lahey Hospital and Medical Center, Peabody, Massachusetts.

Karl J. D'Silva, MD, has disclosed no relevant financial relationships.

Image Quizzes are fictional or fictionalized clinical scenarios intended to provide evidence-based educational takeaways.

Based on the patient's presentation and workup, the likely diagnosis is adenosquamous carcinoma of the lung, a relatively rare subtype of non–small cell lung cancer (NSCLC). Adenosquamous carcinoma displays qualities of both squamous cell carcinoma and adenocarcinoma; for definitive diagnosis, the cancer must contain 10% of each of these major NSCLC subtypes. Maeda and colleagues concluded that adenosquamous carcinoma occurs more frequently among men and that the age at the time of diagnosis is higher among such cancers compared with adenocarcinoma. Several studies have confirmed that adenosquamous carcinoma of the lung is also more prevalent among smokers. 

Though a diagnosis of adenosquamous carcinoma may be suspected after small biopsies, cytology, or excisional biopsies, definitive diagnosis necessitates a resection specimen. If any adenocarcinoma component is observed in a biopsy specimen that is otherwise squamous, as in the present case, this finding is an indication for molecular testing. Epidermal growth factor receptor (EGFR) mutations may be present in adenosquamous carcinoma cancers, despite a majority of cancers with EGFR mutations being among nonsmokers or former light smokers with adenocarcinoma histology. In addition, even for patients diagnosed with squamous cell carcinoma, adenosquamous carcinoma should be considered if genetic testing suggests EGFR mutations.

Relative to adenocarcinoma and squamous cell carcinoma, adenosquamous carcinoma has higher grade malignancy, more advanced postoperative stage, and stronger lymph nodal invasiveness. In terms of treatment, surgical resection is the curative option for adenosquamous carcinoma of the lung, with lobectomy with lymphadenectomy considered for first-line treatment. Though the most beneficial chemotherapy regimen for patients with adenosquamous carcinoma of the lung remains the subject of investigation, platinum-based doublet chemotherapy is the current standard treatment option. EGFR tyrosine kinase inhibitors may be an effective option for EGFR-positive patients. 

Karl J. D'Silva, MD, Clinical Assistant Professor, Department of Medicine, Tufts University School of Medicine, Boston; Medical Director, Department of Oncology and Hematology, Lahey Hospital and Medical Center, Peabody, Massachusetts.

Karl J. D'Silva, MD, has disclosed no relevant financial relationships.

Image Quizzes are fictional or fictionalized clinical scenarios intended to provide evidence-based educational takeaways.

Based on the patient's presentation, history, and imaging results, the likely diagnosis is non–small cell lung cancer (NSCLC) of an adenocarcinoma subtype. NSCLC accounts for about 80% of all lung cancer cases. Adenocarcinoma, in particular, is the most common type of lung cancer in the United States, accounting for about 40% of cases. This subtype is also the most common histology among nonsmokers. Still, individuals aged 55 to 77 years with a smoking history of 30 pack-years or more are considered to be the highest-risk group for lung cancer; those who quit less than 15 years ago — like the patient in the present case — are still considered to be in this risk group. Most cases of lung cancer are diagnosed at a late stage when symptoms have already begun to manifest. However, it should be noted that women are more likely to develop adenocarcinoma, are generally younger when they present with symptoms, and are more likely to present with localized disease. It remains to be proven whether the use of HRT affects the risk for lung cancer in women. Deaths from lung cancer, and in particular NSCLC, were shown to be higher among patients undergoing HRT, though no increase in lung cancer death was reported in women receiving estrogen alone. 

In addition to the imaging described in this case, workup for NSCLC should include immunohistochemical (IHC) analyses to identify tumor type and lineage (adenocarcinoma, squamous cell carcinoma, metastatic malignancy, or primary pleural mesothelioma). Separate IHC analyses are then used to guide treatment decisions, identifying whether anaplastic lymphoma kinase inhibitor therapy or programmed death-ligand 1 inhibitor therapy would be appropriate. 

Tissue should also be conserved for molecular testing. Management of NSCLC is primarily informed by the presence of targetable mutations. Among adenocarcinoma cases, the most common mutations are in the EGFR and KRAS genes. KRAS mutations, unlike EGFR mutations, are associated with a history of smoking and are considered prognostic biomarkers. Because overlapping targetable alterations are uncommon, patients who are confirmed to be harboring KRAS mutations will likely not benefit from additional molecular testing. Presence of the KRAS mutation suggests a poor response to EGFR tyrosine kinase inhibitors, though it does not appear to impact chemotherapeutic efficacy. Although no targeted therapies are yet available for this population, immune checkpoint inhibitors appear to be beneficial. National Comprehensive Cancer Network guidelines advise that all patients with adenocarcinoma be tested for EGFR mutations and that DNA mutational analysis is the preferred method.

Karl J. D'Silva, MD, Clinical Assistant Professor, Department of Medicine, Tufts University School of Medicine, Boston; Medical Director, Department of Oncology and Hematology, Lahey Hospital and Medical Center, Peabody, Massachusetts.

Karl J. D'Silva, MD, has disclosed no relevant financial relationships.

Based on the patient's presentation, history, and imaging results, the likely diagnosis is non–small cell lung cancer (NSCLC) of an adenocarcinoma subtype. NSCLC accounts for about 80% of all lung cancer cases. Adenocarcinoma, in particular, is the most common type of lung cancer in the United States, accounting for about 40% of cases. This subtype is also the most common histology among nonsmokers. Still, individuals aged 55 to 77 years with a smoking history of 30 pack-years or more are considered to be the highest-risk group for lung cancer; those who quit less than 15 years ago — like the patient in the present case — are still considered to be in this risk group. Most cases of lung cancer are diagnosed at a late stage when symptoms have already begun to manifest. However, it should be noted that women are more likely to develop adenocarcinoma, are generally younger when they present with symptoms, and are more likely to present with localized disease. It remains to be proven whether the use of HRT affects the risk for lung cancer in women. Deaths from lung cancer, and in particular NSCLC, were shown to be higher among patients undergoing HRT, though no increase in lung cancer death was reported in women receiving estrogen alone. 

In addition to the imaging described in this case, workup for NSCLC should include immunohistochemical (IHC) analyses to identify tumor type and lineage (adenocarcinoma, squamous cell carcinoma, metastatic malignancy, or primary pleural mesothelioma). Separate IHC analyses are then used to guide treatment decisions, identifying whether anaplastic lymphoma kinase inhibitor therapy or programmed death-ligand 1 inhibitor therapy would be appropriate. 

Tissue should also be conserved for molecular testing. Management of NSCLC is primarily informed by the presence of targetable mutations. Among adenocarcinoma cases, the most common mutations are in the EGFR and KRAS genes. KRAS mutations, unlike EGFR mutations, are associated with a history of smoking and are considered prognostic biomarkers. Because overlapping targetable alterations are uncommon, patients who are confirmed to be harboring KRAS mutations will likely not benefit from additional molecular testing. Presence of the KRAS mutation suggests a poor response to EGFR tyrosine kinase inhibitors, though it does not appear to impact chemotherapeutic efficacy. Although no targeted therapies are yet available for this population, immune checkpoint inhibitors appear to be beneficial. National Comprehensive Cancer Network guidelines advise that all patients with adenocarcinoma be tested for EGFR mutations and that DNA mutational analysis is the preferred method.

Karl J. D'Silva, MD, Clinical Assistant Professor, Department of Medicine, Tufts University School of Medicine, Boston; Medical Director, Department of Oncology and Hematology, Lahey Hospital and Medical Center, Peabody, Massachusetts.

Karl J. D'Silva, MD, has disclosed no relevant financial relationships.

Based on the patient's presentation, history, and imaging results, the likely diagnosis is non–small cell lung cancer (NSCLC) of an adenocarcinoma subtype. NSCLC accounts for about 80% of all lung cancer cases. Adenocarcinoma, in particular, is the most common type of lung cancer in the United States, accounting for about 40% of cases. This subtype is also the most common histology among nonsmokers. Still, individuals aged 55 to 77 years with a smoking history of 30 pack-years or more are considered to be the highest-risk group for lung cancer; those who quit less than 15 years ago — like the patient in the present case — are still considered to be in this risk group. Most cases of lung cancer are diagnosed at a late stage when symptoms have already begun to manifest. However, it should be noted that women are more likely to develop adenocarcinoma, are generally younger when they present with symptoms, and are more likely to present with localized disease. It remains to be proven whether the use of HRT affects the risk for lung cancer in women. Deaths from lung cancer, and in particular NSCLC, were shown to be higher among patients undergoing HRT, though no increase in lung cancer death was reported in women receiving estrogen alone. 

In addition to the imaging described in this case, workup for NSCLC should include immunohistochemical (IHC) analyses to identify tumor type and lineage (adenocarcinoma, squamous cell carcinoma, metastatic malignancy, or primary pleural mesothelioma). Separate IHC analyses are then used to guide treatment decisions, identifying whether anaplastic lymphoma kinase inhibitor therapy or programmed death-ligand 1 inhibitor therapy would be appropriate. 

Tissue should also be conserved for molecular testing. Management of NSCLC is primarily informed by the presence of targetable mutations. Among adenocarcinoma cases, the most common mutations are in the EGFR and KRAS genes. KRAS mutations, unlike EGFR mutations, are associated with a history of smoking and are considered prognostic biomarkers. Because overlapping targetable alterations are uncommon, patients who are confirmed to be harboring KRAS mutations will likely not benefit from additional molecular testing. Presence of the KRAS mutation suggests a poor response to EGFR tyrosine kinase inhibitors, though it does not appear to impact chemotherapeutic efficacy. Although no targeted therapies are yet available for this population, immune checkpoint inhibitors appear to be beneficial. National Comprehensive Cancer Network guidelines advise that all patients with adenocarcinoma be tested for EGFR mutations and that DNA mutational analysis is the preferred method.

Karl J. D'Silva, MD, Clinical Assistant Professor, Department of Medicine, Tufts University School of Medicine, Boston; Medical Director, Department of Oncology and Hematology, Lahey Hospital and Medical Center, Peabody, Massachusetts.

Karl J. D'Silva, MD, has disclosed no relevant financial relationships.

On the basis of the patient's presentation and imaging results, the likely diagnosis is non–small cell cancer (NSCLC) of an adenocarcinoma subtype. NSCLC makes up about 80% of all lung cancer cases. Adenocarcinoma in particular is the most common type of lung cancer in the United States, accounting for about 40% of cases, and it is the most common histology among nonsmokers. Women are more likely to develop this subtype of NSCLC and are generally younger when they present with symptoms. This type of cancer arises from the bronchial mucosal glands and usually develops in a peripheral location within the lung. 

In the course of workup, immunohistochemical (IHC) analyses are used to identify tumor type and lineage (adenocarcinoma, squamous cell carcinoma, metastatic malignancy, or primary pleural mesothelioma). Separate IHC analyses are then used to guide treatment decisions, identifying whether ALK inhibitor therapy or programmed cell death protein ligand 1 (PD-L1) inhibitor therapy would be appropriate.

Tissue should also be conserved for molecular testing. NCCN guidelines advise that all patients with adenocarcinoma should be tested for EGFR mutations, and DNA mutational analysis is the preferred method for assessment. Patients should also undergo routine biomarker testing, with an eye toward ALK, RET, and ROS1 rearrangements, BRAF mutations, c-MET and exon 14 skipping mutations, and PD-L1 expression levels. For patients with metastatic NSCLC, PD-L1 IHC testing is recommended.

Most cases of lung cancer are diagnosed at a late stage, when symptoms have already begun to manifest. Of note, however, women with adenocarcinoma are more likely to present with localized disease. Treatment is largely influenced by the presence of targetable mutations. Among adenocarcinoma cases, the most common mutations are in the EGFR and KRAS genes.

For patients who are EGFR mutation positive (exon 10 deletion or L858R), osimertinib is the recommended first-line therapy. For patients who are positive for the EGFR exon 20 insertion mutation, initial systemic therapy options for adenocarcinoma are appropriate; the preferred regimen being pembrolizumab-carboplatin-pemetrexed if there are no contraindications to programmed cell death protein 1 (PD-1) or PD-L1 inhibitors.

KRAS mutations, unlike EGFR mutations, are associated with smoking. Because overlapping targetable alterations are uncommon, identification of KRAS mutations suggests that these patients will not benefit from additional molecular testing. Again, initial systemic therapy options for adenocarcinoma are appropriate, but the presence of KRAS mutation predicts a poor response to EGFR tyrosine kinase inhibitors. The FDA approved a KRAS inhibitor in June 2021 and immune checkpoint inhibitors appear to be beneficial in this population.

Maurie Markman, MD, President, Department of Medical Oncology, Cancer Treatment Centers of America.

Maurie Markman, MD, has disclosed the following relevant financial relationships:

Serve(d) as a director, officer, partner, employee, advisor, consultant, or trustee for: Merck
Serve(d) as a speaker or a member of a speakers bureau for: AstraZeneca; Novis; Glaxo Smith Kline
Received research grant from: AstraZeneca; Novis; GSK; Merck

On the basis of the patient's presentation and imaging results, the likely diagnosis is non–small cell cancer (NSCLC) of an adenocarcinoma subtype. NSCLC makes up about 80% of all lung cancer cases. Adenocarcinoma in particular is the most common type of lung cancer in the United States, accounting for about 40% of cases, and it is the most common histology among nonsmokers. Women are more likely to develop this subtype of NSCLC and are generally younger when they present with symptoms. This type of cancer arises from the bronchial mucosal glands and usually develops in a peripheral location within the lung. 

In the course of workup, immunohistochemical (IHC) analyses are used to identify tumor type and lineage (adenocarcinoma, squamous cell carcinoma, metastatic malignancy, or primary pleural mesothelioma). Separate IHC analyses are then used to guide treatment decisions, identifying whether ALK inhibitor therapy or programmed cell death protein ligand 1 (PD-L1) inhibitor therapy would be appropriate.

Tissue should also be conserved for molecular testing. NCCN guidelines advise that all patients with adenocarcinoma should be tested for EGFR mutations, and DNA mutational analysis is the preferred method for assessment. Patients should also undergo routine biomarker testing, with an eye toward ALK, RET, and ROS1 rearrangements, BRAF mutations, c-MET and exon 14 skipping mutations, and PD-L1 expression levels. For patients with metastatic NSCLC, PD-L1 IHC testing is recommended.

Most cases of lung cancer are diagnosed at a late stage, when symptoms have already begun to manifest. Of note, however, women with adenocarcinoma are more likely to present with localized disease. Treatment is largely influenced by the presence of targetable mutations. Among adenocarcinoma cases, the most common mutations are in the EGFR and KRAS genes.

For patients who are EGFR mutation positive (exon 10 deletion or L858R), osimertinib is the recommended first-line therapy. For patients who are positive for the EGFR exon 20 insertion mutation, initial systemic therapy options for adenocarcinoma are appropriate; the preferred regimen being pembrolizumab-carboplatin-pemetrexed if there are no contraindications to programmed cell death protein 1 (PD-1) or PD-L1 inhibitors.

KRAS mutations, unlike EGFR mutations, are associated with smoking. Because overlapping targetable alterations are uncommon, identification of KRAS mutations suggests that these patients will not benefit from additional molecular testing. Again, initial systemic therapy options for adenocarcinoma are appropriate, but the presence of KRAS mutation predicts a poor response to EGFR tyrosine kinase inhibitors. The FDA approved a KRAS inhibitor in June 2021 and immune checkpoint inhibitors appear to be beneficial in this population.

Maurie Markman, MD, President, Department of Medical Oncology, Cancer Treatment Centers of America.

Maurie Markman, MD, has disclosed the following relevant financial relationships:

Serve(d) as a director, officer, partner, employee, advisor, consultant, or trustee for: Merck
Serve(d) as a speaker or a member of a speakers bureau for: AstraZeneca; Novis; Glaxo Smith Kline
Received research grant from: AstraZeneca; Novis; GSK; Merck

On the basis of the patient's presentation and imaging results, the likely diagnosis is non–small cell cancer (NSCLC) of an adenocarcinoma subtype. NSCLC makes up about 80% of all lung cancer cases. Adenocarcinoma in particular is the most common type of lung cancer in the United States, accounting for about 40% of cases, and it is the most common histology among nonsmokers. Women are more likely to develop this subtype of NSCLC and are generally younger when they present with symptoms. This type of cancer arises from the bronchial mucosal glands and usually develops in a peripheral location within the lung. 

In the course of workup, immunohistochemical (IHC) analyses are used to identify tumor type and lineage (adenocarcinoma, squamous cell carcinoma, metastatic malignancy, or primary pleural mesothelioma). Separate IHC analyses are then used to guide treatment decisions, identifying whether ALK inhibitor therapy or programmed cell death protein ligand 1 (PD-L1) inhibitor therapy would be appropriate.

Tissue should also be conserved for molecular testing. NCCN guidelines advise that all patients with adenocarcinoma should be tested for EGFR mutations, and DNA mutational analysis is the preferred method for assessment. Patients should also undergo routine biomarker testing, with an eye toward ALK, RET, and ROS1 rearrangements, BRAF mutations, c-MET and exon 14 skipping mutations, and PD-L1 expression levels. For patients with metastatic NSCLC, PD-L1 IHC testing is recommended.

Most cases of lung cancer are diagnosed at a late stage, when symptoms have already begun to manifest. Of note, however, women with adenocarcinoma are more likely to present with localized disease. Treatment is largely influenced by the presence of targetable mutations. Among adenocarcinoma cases, the most common mutations are in the EGFR and KRAS genes.

For patients who are EGFR mutation positive (exon 10 deletion or L858R), osimertinib is the recommended first-line therapy. For patients who are positive for the EGFR exon 20 insertion mutation, initial systemic therapy options for adenocarcinoma are appropriate; the preferred regimen being pembrolizumab-carboplatin-pemetrexed if there are no contraindications to programmed cell death protein 1 (PD-1) or PD-L1 inhibitors.

KRAS mutations, unlike EGFR mutations, are associated with smoking. Because overlapping targetable alterations are uncommon, identification of KRAS mutations suggests that these patients will not benefit from additional molecular testing. Again, initial systemic therapy options for adenocarcinoma are appropriate, but the presence of KRAS mutation predicts a poor response to EGFR tyrosine kinase inhibitors. The FDA approved a KRAS inhibitor in June 2021 and immune checkpoint inhibitors appear to be beneficial in this population.

Maurie Markman, MD, President, Department of Medical Oncology, Cancer Treatment Centers of America.

Maurie Markman, MD, has disclosed the following relevant financial relationships:

Serve(d) as a director, officer, partner, employee, advisor, consultant, or trustee for: Merck
Serve(d) as a speaker or a member of a speakers bureau for: AstraZeneca; Novis; Glaxo Smith Kline
Received research grant from: AstraZeneca; Novis; GSK; Merck

The diagnosis is squamous cell carcinoma. A central or hilar mass is most likely to be a squamous cell carcinoma or a small cell tumor and less commonly an adenocarcinoma. Histologically, when there is lack of cohesion among the epithelial cells due to malignant changes, the cells get arranged in a concentric manner. The fate of a squamous cell is to form keratin, so these cells lay down keratin in a concentric manner and then appear as keratin pearls. 

This patient's tumor is found to have programmed cell death–ligand 1 ≥ 1% and has no actionable molecular markers. The patient has a performance status score of 1. In a patient with advanced or metastatic squamous cell carcinoma with a performance status score of 1, the National Comprehensive Cancer Network recommends pembrolizumab/carboplatin/paclitaxel or pembrolizumab/carboplatin/albumin-bound paclitaxel as preferred regimens. The pembrolizumab component is based on the results of the KEYNOTE-407 trial. In patients with previously untreated metastatic, squamous non-small cell lung cancer, the addition of pembrolizumab to chemotherapy with carboplatin plus paclitaxel or nab-paclitaxel resulted in significantly longer overall survival and progression-free survival than chemotherapy alone.

Maurie Markman, MD, President, Department of Medical Oncology, Cancer Treatment Centers of America.

Maurie Markman, MD, has disclosed the following relevant financial relationships:

Serve(d) as a director, officer, partner, employee, advisor, consultant, or trustee for: Merck
Serve(d) as a speaker or a member of a speakers bureau for: AstraZeneca; Novis; Glaxo Smith Kline
Received research grant from: AstraZeneca; Novis; GSK; Merck

The diagnosis is squamous cell carcinoma. A central or hilar mass is most likely to be a squamous cell carcinoma or a small cell tumor and less commonly an adenocarcinoma. Histologically, when there is lack of cohesion among the epithelial cells due to malignant changes, the cells get arranged in a concentric manner. The fate of a squamous cell is to form keratin, so these cells lay down keratin in a concentric manner and then appear as keratin pearls. 

This patient's tumor is found to have programmed cell death–ligand 1 ≥ 1% and has no actionable molecular markers. The patient has a performance status score of 1. In a patient with advanced or metastatic squamous cell carcinoma with a performance status score of 1, the National Comprehensive Cancer Network recommends pembrolizumab/carboplatin/paclitaxel or pembrolizumab/carboplatin/albumin-bound paclitaxel as preferred regimens. The pembrolizumab component is based on the results of the KEYNOTE-407 trial. In patients with previously untreated metastatic, squamous non-small cell lung cancer, the addition of pembrolizumab to chemotherapy with carboplatin plus paclitaxel or nab-paclitaxel resulted in significantly longer overall survival and progression-free survival than chemotherapy alone.

Maurie Markman, MD, President, Department of Medical Oncology, Cancer Treatment Centers of America.

Maurie Markman, MD, has disclosed the following relevant financial relationships:

Serve(d) as a director, officer, partner, employee, advisor, consultant, or trustee for: Merck
Serve(d) as a speaker or a member of a speakers bureau for: AstraZeneca; Novis; Glaxo Smith Kline
Received research grant from: AstraZeneca; Novis; GSK; Merck

The diagnosis is squamous cell carcinoma. A central or hilar mass is most likely to be a squamous cell carcinoma or a small cell tumor and less commonly an adenocarcinoma. Histologically, when there is lack of cohesion among the epithelial cells due to malignant changes, the cells get arranged in a concentric manner. The fate of a squamous cell is to form keratin, so these cells lay down keratin in a concentric manner and then appear as keratin pearls. 

This patient's tumor is found to have programmed cell death–ligand 1 ≥ 1% and has no actionable molecular markers. The patient has a performance status score of 1. In a patient with advanced or metastatic squamous cell carcinoma with a performance status score of 1, the National Comprehensive Cancer Network recommends pembrolizumab/carboplatin/paclitaxel or pembrolizumab/carboplatin/albumin-bound paclitaxel as preferred regimens. The pembrolizumab component is based on the results of the KEYNOTE-407 trial. In patients with previously untreated metastatic, squamous non-small cell lung cancer, the addition of pembrolizumab to chemotherapy with carboplatin plus paclitaxel or nab-paclitaxel resulted in significantly longer overall survival and progression-free survival than chemotherapy alone.

Maurie Markman, MD, President, Department of Medical Oncology, Cancer Treatment Centers of America.

Maurie Markman, MD, has disclosed the following relevant financial relationships:

Serve(d) as a director, officer, partner, employee, advisor, consultant, or trustee for: Merck
Serve(d) as a speaker or a member of a speakers bureau for: AstraZeneca; Novis; Glaxo Smith Kline
Received research grant from: AstraZeneca; Novis; GSK; Merck