NCCN Guidelines for Patients® | Lung Cancer - Non-Small Cell Lung Cancer

36 NCCN Guidelines for Patients ® : Lung Cancer – Non-Small Cell, 2018 Cancer lab tests Samples from the biopsy or surgery will be sent to a pathologist. A pathologist is a doctor who’s an expert in testing cells to find disease. He or she will examine the samples using a microscope. All lab results are recorded in a pathology report. It’s a good idea to get a copy of your pathology report. It’s used to plan treatment. Histologic typing The pathologist will study the parts of the cancer cells to classify the disease. This is called histologic typing. The pathology report will state if the cancer started in the lung or elsewhere. If the cancer started in the lung, the report will also list the type of lung cancer. Histologic subtypes of NSCLC include squamous cell carcinoma, adenocarcinoma, large-cell lung carcinoma, and other rare types. Squamous cells are thin and flat and line the airways of the lung. Adenocarcinoma is a cancer of epithelial cells that make fluids to keep the lungs moist. Large-cell lung carcinomas lack features to classify them as any other carcinoma. The pathologist will also help with assessing how far the cancer has grown and spread. He or she will measure the size of the primary tumor. Lymph nodes and other removed tissue will be studied for cancer cells. If the cancer appears to have spread to a distant site, the pathologist will assess if the tumor cells from the distant site are from your lung. Biomarker testing Another task of pathologists is to do biomarker (or molecular) testing. Biomarker testing includes tests of genes or their products (proteins) within cancer cells. It is done because not all lung cancers are alike. Lung cancer can differ between people by which genes are present. Biomarker testing is used to plan treatment for metastatic lung cancers. Overactive EGFR mutations EGFR ( e pidermal g rowth f actor r eceptor) is a surface receptor. A surface receptor is a protein in the outer membrane of cells that starts changes within a cell when turned on. See Figure 12 . Mutations in the gene that controls EGFR cause the receptors to be overactive. EGFR overactivity causes new cancer cells to form quickly. EGFR mutation testing is advised for metastatic lung adenocarcinomas, large-cell lung carcinomas, and unknown subtypes. Very few squamous cell carcinomas have overactive EGFR mutations. However, EGFR mutation testing of metastatic squamous cell carcinomas may be considered. It may be done for people who never smoked and for mixed histology. Testing for EGFR is approved both from a tissue sample or blood sample. ALK gene rearrangement For some lung cancers, the growth of the cancer cells is caused in part by an ALK ( a naplastic l ymphoma k inase) gene rearrangement. A gene rearrangement is the fusion of one gene with another gene to create a new gene. In some lung cancers, ALK fuses with EML4 . The ALK-EML4 fusion gene makes an overactive ALK surface receptor that helps lung cancer cells grow. ALK testing is advised for metastatic lung adenocarcinomas, large-cell lung carcinomas, and unknown subtypes. Very few squamous cell carcinomas have an ALK gene rearrangement. However, ALK testing of metastatic squamous cell carcinomas may be considered. It may be done for people who never smoked and for mixed histology. An ALK rearrangement does not usually occur with EGFR , ROS1 , and KRAS mutations. ROS1 gene rearrangement About 2 out of every 100 lung adenocarcinomas (2%) consist of cells with a ROS1 gene rearrangement. Several genes have been found to fuse with 4 Treatment planning Cancer lab tests

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