Not all cancers will ever have an identified cause, but some cancers are genetically linked, meaning that inherited genetic mutations from your parents increase your risk of developing the disease. These types of mutations are called germline mutations. Another type of genetic mutation is called a somatic mutation, which means that the mutation arose in the tumor itself. Today’s genetic tests not only uncover whether a person has an inherited risk of developing ovarian cancer, but can distinguish between somatic and germline mutations. And the information can be crucial for determining the best treatment.
“The importance of genetic testing in patients with ovarian cancer cannot be overstated,” says Dr. Ramez Eskander, gynecologic oncologist at the University of California, San Diego. “Genetic testing may not only inform and guide treatment decisions, but it’s also important for identifying opportunities for future treatment strategies.”
Inherited Genetic Mutations
Studies show that between 10 and 15 percent of high-grade epithelial ovarian cancers–the most common type of ovarian cancer–have an inherited component . That’s one reason the Society of Gynecologic Oncology recommends that ovarian cancer patients — and, in some cases, their immediate family members — undergo genetic testing.
Called germline testing, genetic testing for inherited mutations can uncover whether a patient has inherited a BRCA1 or BRCA2 gene mutation. Finding inherited genetic risk can also provide critical information for family members who can go for genetic counseling to see if prophylactic surgery or frequent screening is recommended. Knowing about germline testing can also help couples make decisions about family building.
“If family members test positive for the BRCA mutation, they can have a risk-reducing surgery to prevent the cancer from developing in the first place,” Dr. Eskander says. “So, not only does genetic testing in the germline matter for the patient, but it has really important implications for family members who may be tested and identified to carry the mutation before they’re ever diagnosed with a cancer.”
Doctors can also test the tumor itself to identify mutations that triggered the cancer. These accumulated changes that occur after you were born and throughout your life are called somatic changes. “There may be mutations in the tumor itself that are not inherited, but are still important to guide treatment decisions,” Dr. Eskander explains. Doctors can even test the tumor’s response to different treatments after tissue is removed during a surgical resection.
Genetic testing, both germline and somatic, can now play an important role in which treatment protocol your oncologist selects for your ovarian cancer. For example, studies show that patients with a BRCA mutation often respond particularly well to PARP inhibitor drugs; these drugs work by preventing cancer cells from repairing their genetic material when damaged, causing them to die.
While initially, women with a BRCA-1 or BRCA-2 genetic mutation had been shown to respond especially well to PARP inhibitors when given after recurrence, newer research has shown that women with the BRCA gene mutation (and indeed almost all women) can consider using PARP inhibitors throughout their treatment. The Food and Drug Administration has now approved niraparib (brand name ZEJULA) for almost all women regardless of whether they have the BRCA mutation, as part of an initial course of treatment, or what’s called front-line treatment.
Most recently, 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.
If you test positive for BRCA1 or BRCA2, chances are good that your oncologist will use that information to determine which treatment protocol is right for you.
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