By: Susan Branton, M.D.
UPMC Magee-Womens Breast Health Center
Genetic testing to discover ancestry is common practice and sometimes discovering your family history can reveal unexpected connections, new storylines, and a world of new relatives. But, there’s another benefit for some specific types of genetic testing. The genes you inherit can help doctors determine your cancer risk, including your risk for breast and ovarian cancer.
Everyone has a unique genetic code that is a combination of genes from their parents. Mutations or changes in certain genes can increase the likelihood that certain cells could become cancerous. Pancreas, thyroid, colon, bone, breast, ovarian, soft tissue, and melanoma are cancers that possibly can be linked with genetic mutations. Mutations of the BRCA1 and BRCA2 genes are specifically linked to breast and ovarian cancer. People with Ashkenazi Jewish ancestry have a higher incidence of having the BRCA gene mutation. African American women who have a higher rate of estrogen-receptor negative breast cancer also have higher rates of the BRCA1, BRCA2, and another gene called PALB2 that is linked to breast cancer.
So where do you start? At age 18, women should begin talking to their family doctors about their breast and ovarian cancer risks. Important factors that could impact your risk include your age at menses, age at first childbirth, weight, lifestyle, and genetic or family history.
To ensure that you have an accurate family health history, ask your parents and grandparents to document any medical history of ovarian, breast, and other cancers in the family to help younger generations know who and at what age these were discovered. At a minimum, go back at least three generations from both sides of the family. A female family member who was diagnosed with ovarian cancer at any age could indicate presence of a gene mutation. A female family member diagnosed with premenopausal breast cancer could indicate the presence of a gene mutation, whereas a relative who developed breast cancer after menopause is somewhat less likely to point to a genetic mutation even though this is still important to record.
Research continues into the relationship between genetics and cancer risk, and current data indicates that only 10% of cancers are hereditary. The findings from your family history help your doctor determine if you would benefit from genetic testing. The test can be performed by your physician or through a referral to a genetic counselor to review your family history, and the sample is taken with a simple mouth swab or blood sample.
It is rare to carry the BRCA or BRCA2 mutations, and testing positive for it is not a guarantee that you will develop breast or ovarian cancer — it is, however, an indicator that you are at risk. Because ovarian cancer is “silent” and doesn’t produce any symptoms until it is well-advanced, eliminating risks for this condition is a priority. Closely managed screenings for breast cancer, through yearly mammograms and breast MRIs, preventive surgery, and use of certain medications can help reduce the risk of breast cancer for those who have the BRCA mutation.
The absence of BRCA mutations does not guarantee that you will not develop breast or ovarian cancer. In fact, these mutations are only responsible for five percent of all breast cancer cases. Proven ways to reduce your breast cancer risks include managing your weight, eating a diet that includes plenty of fruits and vegetables, regular exercise, limiting alcohol, and not smoking.
No matter what your breast cancer risk is, early detection provides you with the best odds for beating cancer. Most doctors in the United States agree that beginning at age 40 (earlier if you do have a family history), women should have an annual mammogram to detect breast cancer at its earliest stages and when treatment can be the most effective.
Susan Branton, M.D., is the medical director of UPMC Magee-Womens Breast Health Center, UPMC Williamsport Divine Providence Campus, 1100 Grampian Blvd., Williamsport. To schedule an appointment with Dr. Branton or learn more about breast health, call 570-326-8200 or go to UPMC.com/BreastNCPA.