Some biomarkers may be tested using blood samples, while others require cancer cells collected from tumor tissue. Your healthcare team can collect tissue from the tumor with surgery or a biopsy to test for ovarian cancer tumor markers.

Biomarkers in the tumor tissue may indicate how fast the cancer is growing, which treatment types will be most effective, and how likely the cancer is to come back (recur) after treatment.

You may have heard about BRCA gene mutations (gene changes) for breast cancer. The BRCA1 and BRCA2 genes make proteins that repair DNA and prevent tumor growth. When someone inherits a harmful change in one of these genes, the risk of certain cancers increases.

When tumor cells test positive for a BRCA mutation, it could mean that you inherited the mutation from a parent. It could also be a somatic mutation, meaning the change developed in the tumor rather than being inherited.

Doctors recommend testing for BRCA mutations as soon as you’re diagnosed with ovarian cancer. If your tumor cells show a BRCA mutation, your healthcare team will likely recommend genetic testing to determine if you inherited the mutation.

People who test positive for a BRCA mutation in their cancer cells may benefit from a type of cancer treatment called poly(ADP-ribose) polymerase (PARP) inhibitors. This targeted therapy blocks the PARP enzyme from repairing damaged DNA in cells. PARP inhibitors can kill cancer cells by preventing the cells from being able to repair their damaged DNA.

PARP inhibitors approved for ovarian cancer treatment include:

• Olaparib (Lynparza)
• Niraparib (Zejula)
• Rucaparib (Rubraca)

Another biomarker test recommended at the start of treatment checks for homologous recombination deficiency (HRD), a condition that makes it harder for cancer cells to repair damaged DNA.

People who test positive for HRD may benefit from a PARP inhibitor as part of their maintenance therapy.

Some ovarian cancer cells have a biomarker called microsatellite instability-high (MSI-high). This is often associated with deficient mismatch repair (dMMR), which means cancer cells have trouble repairing mistakes in their DNA. A pathologist may use a lab technique called immunohistochemistry to check for dMMR. Other tests can identify MSI-high in cancer cells.

People with Lynch syndrome are more likely to have MSI-high cancers. These cancers may respond to a type of immunotherapy called immune checkpoint inhibitors.

For instance, pembrolizumab (Keytruda) is an immune checkpoint inhibitor that helps the immune system find and attack cancer cells. It may be an option for certain people with ovarian cancer, depending on their test results and previous treatments.

An immunohistochemistry test can also identify folate receptor alpha (FR alpha) in cancer cells. Your oncologist may recommend this test after BRCA and HRD testing.

Testing positive for FR-alpha could mean that you’d benefit from another type of targeted therapy. Mirvetuximab soravtansine-gynx (Elahere) is an antibody-drug conjugate used to treat certain cases of advanced or recurrent ovarian cancer that test positive for FR-alpha and no longer respond to platinum-based chemotherapy after one to three previous systemic treatments.

Human epidermal growth factor receptor 2 (HER2) is a protein that controls how cells grow and divide. Some types of ovarian cancer cause HER2 overexpression, where the cells produce large amounts of HER2.

Your oncologist may order an HER2 test after testing for BRCA mutations and HRD. People with advanced ovarian cancer that tests strongly positive for HER2 may qualify for a targeted therapy called fam-trastuzumab deruxtecan-nxki (Enhertu) if they’ve already received treatment and have no other suitable treatment options.

Inherited BRCA1 or BRCA2 Mutation

Lynch Syndrome Gene Mutations