Member: My mother had breast cancer and I know it can run in the family. Should I have a genetic test done to see if I’m at risk? —Melanie, St. Paul
Dr. Fendrich: Thank you for the question, Melanie. It’s true that family history is a common risk for breast cancer. In fact, having a first degree relative, such as your mother, with breast cancer almost doubles your risk for the disease.
If you also have a second first-degree relative who also had breast cancer, the risk is greater — but developing cancer is still far from a certainty.
Most hereditary (from your family) breast cancer comes from an abnormality in the basic unit of life (genes). The most common of these are BRCA1 and BRCA2, though there are many others. A BRCA gene test — conducted as a blood test — can determine whether harmful changes have occurred in either of these genes. However, results are not always definitive.
A positive test would mean there’s an increased breast cancer risk because of a gene abnormality (mutation), but a negative test doesn’t always mean that you do not have a risk of developing breast cancer. If you have a gene mutation that hasn’t been discovered yet, or you have a gene variant that doctors are unsure of, you could still be at risk.
So, should you get tested? It’s possible that a test could be beneficial, but ultimately the decision is best made with your doctor, based on your specific risk factors. If you think you might have an increased risk of developing breast cancer, discuss this with your doctor. Your doctor might refer you to a genetic counselor who is a specialist in genetic abnormalities. It’s also a good idea to check with your health plan to make sure tests are covered.
For others thinking about genetic testing for breast cancer, it should be noted that about eight out of 10 women diagnosed have no family history of the disease. Genetic testing is generally reserved for women with clearly identified high risks.
The best preventive measure against breast cancer is still the routine mammogram — every two years or annually, if your doctor recommends it.
1