Molecular Tests in Ovarian Cancer
- Despite data showing up to 80% of women with ovarian cancer not getting a genetic test, all patients should be offered genetic testing after an ovarian cancer diagnosis
- Roughly 20% or one in five women have a hereditary predisposition of ovarian cancer
- If a woman is born with a BRCA1 or BRCA2 mutation, they have up to a 50 percent chance of developing ovarian cancer
- Molecular tests look at the genetic makeup of ovarian cancer tumors
- These tests identify BRCA and other gene mutations and the results can help personalize treatment plans
“We are really recognizing that cancers like ovarian cancer are not just one disease, but many different tumor types,” says Dr. Stefanie Avril, gynecologic pathologist at Case Western Reserve University in Cleveland. “Now, we are really looking at the molecular level.”
What Molecular Tests Tell Your DoctorRead More
Today, molecular, or genetic testing is an integral part of the ovarian cancer diagnostic workup, and is recommended for all women with the disease. Analyzing your tissue sample can help your doctor learn which genes are driving your tumor and enabling it to grow, Dr. Avril says.
About 15% of women with ovarian cancer have an inherited (called germline) BRCA mutation, which increases their risk of developing ovarian cancer, as well as breast cancer and a few other types of cancers. BRCA1 and BRCA2 are proteins that suppress tumors by helping to repair damaged DNA. If these genes are changed, or mutated, the DNA may not be repaired correctly and the cell can potentially turn cancerous. Having a BRCA mutation can also affect how your cancer responds to certain treatments.
How Molecular Tests Guide Treatment
Molecular tests can help your doctor focus in on the treatment that is likely to work best against your cancer. For example, women with BRCA gene mutations often have a stronger response to platinum-based chemotherapy drugs like cisplatin (Platinol) and carboplatin (Paraplatin).
Having a BRCA mutation may also make you a better candidate for a relatively new class of drugs called PARP inhibitors. Cancer cells that contain BRCA mutations are already at a disadvantage because they have trouble repairing their DNA. PARP inhibitors make the repair process even more difficult, which effectively stops the cancer from growing. That’s why women who have BRCA mutations respond particularly well to PARP inhibitor drugs.
However, the American Society of Clinical Oncology (ASCO) released new guidelines recommending PARP inhibitors be offered to women, with or without genetic mutations, who are newly diagnosed with stage III or IV ovarian cancer and have improved with chemotherapy.
Looking to the Future
Molecular testing doesn’t just inform treatment decisions for women who are diagnosed with ovarian cancer today. It might also reshape the future of treatment for this cancer. Researchers are learning more about how ovarian cancers grow and behave, so that they can develop new therapies against them.
“Our research group is interested in not only looking at the genetic makeup of a tumor, but also looking at…all the different cells that are growing in and around this tumor and in particular, the white blood cells and the patient’s immune system and how it has been reacting to that tumor,” Dr. Avril says.
Today, doctors base most of their treatment decisions on how far the cancer has spread and what it looks like under a microscope (which pathologists call its “histology”). The next step is to develop more targeted treatments for germline mutations like BRCA, and to find other biomarkers that could guide researchers toward entirely new therapies.
“What we hope to achieve with our ongoing research is to be able to use all that additional new molecular information to find more targeted and better treatments for each individual patient, and really predict which patient is going to respond best to what treatment,” Dr. Avril says.