For many people, if they have heard about genetic testing for hereditary cancer syndromes at all, most will relate to BRCA1 and BRCA2 genetic testing and its relationship to hereditary breast cancer. Media also contribute to the overall knowledge; often emphasis in reporting BRCA1 and BRCA2 stories is placed on reducing breast cancer risk. However, there is another cancer risk associated with carrying a BRCA gene mutation that may not be the first to be addressed – an increased risk for ovarian cancer.
Women who carry a mutation in BRCA1 or BRCA2 have a lifetime risk for breast cancer ranging from 40% – 85%. Compared to the general population risk of 12%, this is a substantial elevated risk. Additionally, women with BRCA mutations also have an increased risk for a second breast cancer.
But also substantially increased is the risk for ovarian cancer. The lifetime risk for ovarian cancer ranges from 10% – 45% as compared to the general population risk of 2%. Other cancers associated with carrying a BRCA mutation can include male breast cancer, prostate cancer and pancreatic cancer. Options for managing this risk include increased surveillance, use of chemopreventive medications, and preventive surgery.
For women who have an increased risk to develop ovarian cancer, there are several options to manage this risk. Screening with CA-125 testing of the blood and transvaginal ultrasound and/or the use of oral contraceptives are often considered for women under age 35 or who are still considering having children. For women over age 35 and those who have completed their child-bearing, there is a surgical option to reduce the risk of developing this hard to detect cancer – surgical removal of the ovaries and fallopian tubes, also known as a bilateral salpingo-oophorectomy (BSO). By removing the ovaries and fallopian tubes from the body, the risk to develop cancer in this area drops significantly.
A recent study has shown just how significant this decrease in risk is. This study, which observed almost 5,800 women who carry BRCA1 or BRCA2 mutations over the course of almost six years, showed that by preventively removing the ovaries, the risk for developing ovarian, fallopian tube or peritoneal cancer was reduced by 80%! It also found that this preventative surgery reduced the mortality rate of BRCA1 and BRCA2 gene carriers by 77%. This is largely in part due to decreasing the rate of ovarian, fallopian tube and peritoneal cancers in these women. Additionally, removing the ovaries (and thus the main source of estrogen and other hormones) from the body reduces the risk for breast cancer. Therefore, this preventative surgery is quite successful in reducing the risk of cancer for women who carry a BRCA gene mutation.
It is important to remember that while BSO does significantly reduce the risk of ovarian cancer, careful consideration of the risks and benefits of this procedure should be thoroughly discussed with a health care professional. One should weigh the benefit of cancer risk reduction against the consequences of induced surgical menopause on one’s health and quality of life.
Read the reference article: Finch A, et al: Impact of Oophorectomy on Cancer Incidence and Mortality in Women with a BRCA1 or BRCA2 Mutation. J Clin Oncol 32, 2014
Continue learning about ovarian cancer and genetic risk:
- Ovarian cancer: listen to what your body is saying
- BRCA Gene Mutations and Cancer
- Progress in ovarian cancer research
- Breast and Ovarian Cancer Risk Evaluation Program
- Ovarian Cancer
The University of Michigan Cancer Genetics Clinic provides counseling for people with a personal or family history of cancers that may have genetic links. If a link is confirmed, our specialized physician and genetic counselors will develop a plan for additional screening or lifestyle changes to help reduce cancer risk.
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