By Dr. Christine Mullin, M.D.
1.3 % of women in the general population will develop ovarian cancer sometime during their lives. 39 % of women who inherit a harmful BRCA-1 mutation and 11-17 % of women who inherit a harmful BRCA-2 mutation will develop ovarian cancer by age 70. There are other risk factors for ovarian cancer which include a family history of breast, ovarian, and possibly, other cancers; the specific mutation(s) she has inherited; and reproductive history. However, none of these other factors are as strong of a risk factor as the harmful BRCA-1 or BRCA-2 mutation. BRCA-1mutations may also increase a woman’s risk of developing fallopian tube cancer and peritoneal cancer. The Ashkenazi Jewish population have a higher prevalence of harmful BRCA-1 and BRCA-2 mutations than people in the general U.S. population. Other ethnic and geographic populations around the world, such as the Norwegian, Dutch, and Icelandic peoples, also have a higher prevalence of specific harmful BRCA-1 and BRCA-2 mutations.
DNA (from a blood or saliva sample) is needed for mutation testing. The sample is sent to a laboratory for analysis. It usually takes about a month to get the test results. When an individual has a family history that is suggestive of the presence of a BRCA1 or BRCA2 mutation, it may be most informative to first test a family member who has cancer if that person is still alive and willing to be tested. If that person is found to have a harmful BRCA1 or BRCA2 mutation, then other family members may want to consider genetic counseling to learn more about their potential risks and whether genetic testing for mutations in BRCA1 and BRCA2might be appropriate for them.
Several options are available for managing cancer risk in individuals who have a known harmful BRCA-1 or BRCA-2 mutation. These include enhanced screening, prophylactic (risk-reducing) surgery, chemoprevention, and In Vitro Fertilization with Preimplantation Genetic Diagnosis. Screening includes clinical breast examinations beginning at age 25 to 35 years and a mammogram every year, beginning at age 25 to 35 years. No effective ovarian cancer screening methods currently exist. Some groups recommend transvaginal ultrasound, blood tests for the antigen CA-125, and clinical examinations for ovarian cancer screening in women with harmful BRCA1 or BRCA2 mutations, but none of these methods appear to detect ovarian tumors at an early enough stage to reduce the risk of dying from ovarian cancer.
Prophylactic surgery involves removing as much of the “at-risk” tissue as possible. Women may choose to have both breasts removed (bilateral prophylactic mastectomy) to reduce their risk of breast cancer. Surgery to remove a woman’s ovaries and fallopian tubes (bilateral prophylactic salpingo-oophorectomy) can help reduce her risk of ovarian cancer. Removing the ovaries also reduces the risk of breast cancer in premenopausal women by eliminating a source of hormones that can fuel the growth of some types of breast cancer.
Moreover, women of reproductive age desiring future fertility, can chose to freeze their eggs prior to prophylactic removal of their ovaries in order to preserve their fertility. For women with a partner, desiring pregnancy, they can chose the option of In Vitro Fertilization with Preimplantation Genetic Diagnosis where we can test the embryos for the harmful BRCA gene in the embryo so that we can prevent this gene from being passed on to their offspring. Such amazing technology has helped many women have healthy children without the BRCA gene allowing their children to have a reduced risk of both ovarian and breast cancer.
Dr. Christine Mullin, M.D.
Dr. Christine Mullin joined the Northwell Health Fertility team after completing her subspecialty training in Reproductive Endocrinology and Infertility at the NYU Fertility Center of the New York University School of Medicine. She is the Director of the IVF Program and Director of the PGD/PGS Program at Northwell Health Fertility.