Thanks to advances in scientific research, doctors now know that NSCLC has different subtypes. The specific type of NSCLC that you have may be the result of mutations, or changes, that occur in certain genes, which can affect the instructions for cells to grow and divide. Knowing if you have a genetic mutation associated with lung cancer is an important step when approaching your treatment plan and can help you and your care team determine the right course of action.
What are biomarkers?
One type of tumor biomarker is a molecule that indicates the presence of a change in a tumor cell’s genes that may be related to the development or spread of cancer. Another type of biomarker is the presence and level of certain proteins in tumor cells.
Why is it important to know about biomarkers?
The presence or absence of a biomarker may help a doctor choose a specific treatment or clinical trial for an individual based on the characteristics of his or her tumor. If you tested positive for a particular biomarker, your doctor may choose a “biomarker-driven therapy.” This is a type of treatment that is designed to block certain molecules inside the lung cancer cells that might be driving the tumor’s growth. For people whose tumors test positive for a certain biomarker, it may be possible to base their treatment plan on this particular biomarker.1
What biomarkers exist for NSCLC?
Many biomarkers have been identified, but not all of them have a treatment available right now. Many patients will not test positive for a biomarker. Today, biomarkers that can guide therapy include:
Epidermal growth factor receptor (EGFR) is a protein involved in making cells grow and multiply. EGFR mutations are believed to cause cells to multiply more than normal. The EGFR gene mutation occurs in about 10-35% of patients with NSCLC, and nearly half of lung cancer cases in people who never smoked.2,3
The Anaplastic Lymphoma Kinase (ALK) gene can be found in everyone’s DNA. Sometimes the ALK gene can attach to another gene and change the way each gene normally functions. This is called an ALK gene rearrangement and can contribute to cancer cell growth and tumor survival. This change occurs in 3-5% of NSCLC cases.4-6
The ROS1 gene can be found in everyone’s DNA. Sometimes the ROS1 gene can attach to another gene and change the way each gene normally functions. This is called a ROS1 gene rearrangement and can contribute to cancer cell growth and tumor survival. This change occurs in approximately 1% of NSCLC cases.7
Approximately 1-3% of lung adenocarcinoma patients have mutations in the BRAF gene. This mutation is strongly associated with smoking.8
The presence of the protein PD-L1, or programmed death ligand, can be used to help inform treatment decisions when considering immunotherapy. Immunotherapy is a way to treat certain cancers by harnessing the immune system, the body’s natural defense system against disease.9
How do I know if my lung cancer has a biomarker?
Get tested! Tissue from your tumor can be tested to determine if you have any of the known biomarkers. Ideally, you and your doctor should discuss biomarker testing before your first biopsy so that enough tissue is taken to perform the testing. If you already had a biopsy, ask your doctor to find out if enough tissue remains for biomarker testing. If not, you can ask your doctor about having additional tissue removed to test for biomarkers.
Who should be tested for biomarkers?
If you have been diagnosed with NSCLC, you should speak to your doctor about biomarker testing so that together you can decide what type of treatment may be best for your particular case. Not everybody with lung cancer can benefit from biomarker testing, so it is important to discuss why it may or may not be a good idea for you.
Importantly, not everyone will test positive for a biomarker, and not every biomarker has an approved treatment option yet.
What happens if my tumor tests positive for a biomarker? What if it doesn’t?
By getting tested, you have taken an important step in managing your NSCLC. Click here to find questions to help guide a discussion with your doctor about your next steps. Click here to read what biomarker testing has meant for other patients.