There are now over 2.6 million women in America who have been diagnosed with breast cancer. A very small fraction of these women, about 5% to 10%, carry gene mutations that put them at high risk for developing a second breast cancer and ovarian cancer (including the fallopian tube (FT) and primary peritoneal (PP) ovarian cancer subtypes). Because there is no effective screening test for ovarian cancer, and early detection is challenging, women need to learn as much as possible about their personal risk for developing ovarian cancer.
BRCA1 and BRCA2
Genes BRCA1 and BRCA2 are human genes that are involved with cell growth, cell division and DNA repair. Mutations (changes) in these genes can result in a failure to repair DNA that can, in turn, lead to the development of cancer, especially breast and ovarian cancer.
The lifetime risk for developing ovarian cancer is up to 39–46% in BRCA1 carriers and up to 10–27% in BRCA2 carriers. Both men and women can carry BRCA1/2 mutations and have a 50 percent chance of passing the mutation on to each of their children. About 1 in 400 to 1 in 800 people in the general population have a mutation in one of these genes.
While there may be other genes that predispose women to breast cancer and ovarian cancer, BRCA1 and BRCA2 are the most common and well-defined among them. Not all women who inherit an altered BRCA1/2 gene will develop breast cancer and/or ovarian/PP/FT cancer. Certain groups are more likely to carry an altered BRCA1 or BRCA2 gene. For example, about 1 in 40 Jewish women of Eastern European (Ashkenazi) descent have a BRCA1/2 gene mutation.
Women with Breast Cancer
Women diagnosed with breast cancer should determine if they are at risk for ovarian cancer. While this is true for only a very small number of women with breast cancer, specific preventive steps are available. So it is important and worthwhile to determine if any of the risk factors apply to you and then take appropriate action.
Do You Have Any of the Factors Below That Increase Your Chances of Developing Ovarian Cancer Following a Breast Cancer Diagnosis?
- Personal diagnosis of breast cancer diagnosis before age 45.
- A close blood relation on either your mother or father’s side of the family diagnosed with ovarian cancer at any age. A close blood relation includes mother, sister, daughter, grandmother, granddaughter, aunt or niece.
- Personal diagnosis of breast cancer before age 50 with at least one close relative who has had breast cancer before age 50 or ovarian cancer at any age.
- Personal diagnosis of multiple primary cancers (i.e. bilateral breast cancer, or breast and ovarian cancer).
- Close relative with male breast cancer (for example a father, brother, uncle or grandfather). • Two or more close relatives on the same side of the family (either your mother’s or father’s) who had breast cancer before age 50 or ovarian cancer at any age.
- Eastern European (Ashkenazi) Jewish ancestry, and you or a close relative on either side of your family has had breast cancer before age 50 or ovarian cancer at any age.
IF YOU ANSWERED YES TO ANY OF THESE, talk to your doctor about genetic counseling and the possibility of genetic testing to help determine the best screening and prevention strategies for you.