Biomarker Testing for Lung Cancer

What is a biomarker?

A biomarker is something in your body that may be a sign of a health issue or disease, like cancer. Biomarkers can affect how cancer cells grow, multiply, die, or respond to certain treatments. Biomarkers can be found in the cancer cells that are in blood and tissue. Examples of biomarkers are:

• Higher than normal levels of a substance, such as a protein.
• Changes (also known as mutations) in the genes.
• Missing or extra genes.

How do these genetic changes affect my family?

Some biomarkers are linked to changes, or mutations, in genes. When these changes happen only in the cancer cells, they are called somatic mutations. This means they are not inherited—you did not get them from your parents, and you cannot pass them on to your children. Somatic mutations are different from inherited gene changes, like BRCA1 or BRCA2, which can run in families.

How are biomarkers used for lung cancer treatment?

Biomarkers can tell us more about your cancer and how it can be best treated. Some types of lung cancers contain biomarkers in their cells. Some medicines can target some of these biomarkers to treat the cancer. A medicine that targets the biomarker is called a targeted therapy. It may work better for you than other treatments. Targeted therapies are a type of “precision” or personalized medicine. Knowing if you have a lung cancer biomarker will allow you and your provider to decide whether a targeted therapy will work best for your type of cancer.

Who should have biomarker testing?

Your providers may suggest biomarker testing if:

• You are having a biopsy or surgery for a lung mass that may be lung cancer.
• You have a certain type of lung cancer, such as non-small cell lung cancer (NSCLC), for which biomarker testing is often used.

How is my lung tumor tested for biomarkers?

Your provider will order a test for biomarkers. This test is called comprehensive biomarker testing or next-generation sequencing (NGS), and it looks for gene mutations. The test will also look for a protein called PD-L1 on the tumor tissue. There are two ways to do the test, and you may have one or both done:

• Tumor tissue: You will have a biopsy of the lung tumor. This may be done during a bronchoscopy, needle biopsy, or surgery. During the biopsy, your provider takes a piece of the tumor tissue. This tissue is sent to a special lab for biomarker testing.
• Blood test: In some cases, a liquid biopsy may be done, which is a blood test that looks for biomarkers. Some cancers release small pieces of genetic material into the blood, and this test can help find changes (mutations) in the cancer. Liquid biopsy results come back faster than tests done on tumor tissue. However, liquid biopsies may not find all the important biomarkers. If no biomarkers are found in the blood, your provider may wait for the tumor tissue test results before making decisions about your treatment.

What biomarkers does comprehensive testing look for?

Comprehensive testing often looks for hundreds of biomarkers. Currently, treatment is guided by biomarkers in the following 10 genes or proteins: ALK, BRAF, EGFR, MET, NTRK, RET, ROS1, HER2 (ERBB2), KRAS, NRG1, and PD-L1 (can only be tested with tissue).

What will the testing show?

The test results can take a few weeks to get back and will be sent to your provider. This report will say which biomarkers your tumor has, if any. Ask your provider for a copy of this report to keep in your records.

It can be stressful to wait for these results before starting any treatment. Keep in mind that the results are used to choose the cancer treatment that is the best fit for you. It is worth waiting for the results to get the right treatment for your cancer. Some lung cancers do not have any biomarkers, but this is still helpful information in choosing the best treatment.

Will my health insurance pay for this testing?

Most insurance companies and Medicare will pay for biomarker testing for people with advanced NSCLC, the most common type of lung cancer. If your provider wants to perform this test and you do not have advanced NSCLC, you should call your insurance company to ask about coverage. There are programs available to help people pay for this testing if they have limited coverage through their health insurance. Ask your cancer care team for help finding these programs.