The following recommendations are based on currently available but admittedly limited information — and common sense.
If your family has a defined breast cancer gene abnormality but you test negative for the abnormality, your risk of breast cancer is considered to be equal to that of a woman in the general population: 12-13% over the course of your lifetime. Men who test negative for a known breast cancer gene abnormality have the same very low risk of developing breast cancer as men in the general population. Whether you are a woman or a man, testing negative also means that you could not have passed the genetic abnormality on to your children.
As a woman considered to be at average risk of developing breast cancer, you can follow the screening and lifestyle guidelines recommended for most women:
- Practice regular breast self-examination and get annual or semiannual clinical breast exams (depending on your doctor's recommendation).
- Have screening mammograms following the current guidelines for women of average risk: a baseline mammogram at age 40 and annual mammograms after age 40.
- Maintain a healthy lifestyle: eat a low-fat, well-balanced diet, exercise regularly, keep your weight under control, and minimize your intake of alcohol. These strategies will improve your sense of well-being and general health and possibly lower your breast cancer risk.
If your test and your family members’ test results are normal, but many women in your family younger than age 50 have been affected by breast cancer, the cancer in your family could be due to an inherited genetic abnormality that has not yet been identified. The same holds true if your results were normal but you were unable to have a family member with cancer tested first. These genetic test results are sometimes called “uninformative” or “indeterminate” results. For suggestions about what to do under these circumstances, see the What to Do If Your Genetic Test Results Are Uncertain page.