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, such as cancer. Biomarkers can affect how cancer cells grow, multiply, die, or respond to certain treatments. Biomarkers can be found in the blood, urine, stool, and in cancer cells. 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?

Certain biomarkers involve gene mutations. When these mutations affect cancer cells, they cannot get passed down in families. If you have a gene mutation in your cancer cells, it was not passed down to you from your parents. You cannot pass it on to your children. Mutations in cancer cells are different from genetic mutations that get passed down in families, such as the BRCA1 and BRCA2 gene mutations.

How are biomarkers used in cancer?

Biomarkers can tell us more about your cancer and how it can be treated best. For example:

• Some cancer biomarkers cause cancer cells to grow. If there is a medicine that can block these biomarkers, the medicine may stop the cancer from growing.
• Other biomarkers can fix damage to cancer cells, such as damage caused by chemotherapy. If a medicine can block these biomarkers, the medicine may help chemotherapy work better at killing cancer cells.
• Biomarkers can be used to figure out how your cancer would respond to different treatments.

How are biomarkers used for lung cancer treatment?

Some types of lung cancers contain biomarkers in their cells. There are medicines that 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 sample: In some cases, you may have blood drawn for biomarker testing because cancers can release some genetic material into the bloodstream. This is called a liquid biopsy. The results from a liquid biopsy come back sooner than tumor tissue testing but may not find all the biomarkers that a tumor tissue test does. In some cases, your provider may get the liquid biopsy result and want to wait for the tumor tissue test results before deciding on treatment.

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 contains, 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.

What biomarkers does comprehensive testing look for?

Comprehensive testing often looks for over 100 biomarkers. Currently, treatment is guided by biomarkers in the following 10 genes or proteins: ALK, BRAF, EGFR, MET, NTRK, RET, ROS1, HER2 (ERBB2), KRAS, PD-L1 (can only be tested with tissue).

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 in finding these programs.