I have breast cancer in my family. Should I choose the more aggressive treatment? Should I have surgery to remove my healthy breast to keep from getting breast cancer in it? Should I have genetic testing?

Most women who have breast cancer in their families will never get the disease themselves — even if a mother or sister has died of breast cancer. The risk is higher for women who are known to have a harmful mutation in either the BRCA1 or BRCA2 gene than in women with "breast cancer in their families" who don't have a mutation in one of these genes. But many women with a harmful BRCA1 or BRCA2 mutation may never get breast cancer.
Although a family history of breast cancer increases your risk of breast cancer, it is not necessary to choose more aggressive treatment or more radical surgery just because you have a family member with breast cancer. For most women, family history alone should not influence the decision about which type of surgical treatment to have for early-stage breast cancer.
Women who have a family history of breast cancer do have an increased risk of getting breast cancer in their healthy breast. Sometimes these women decide to have the healthy breast removed to lower their risk of cancer in the future. Occasionally, women with a known harmful BRCA1 or BRCA2 mutation or a strong family history of breast cancer decide to have both their breasts removed as a preventive measure, even if they have never been diagnosed with breast cancer. Preventive mastectomy reduces the risk of future breast cancer, but it does not eliminate the risk completely because cancer can occur in any remaining breast tissue or on the chest wall. The disadvantage is that the surgery will be unnecessary for many women who choose it, because many women who have a breast removed as a preventive measure would never have gotten breast cancer even if the breast (or both breasts) were not removed. Women thinking about preventive mastectomy should get a second professional opinion before taking this step.
Instead of surgery, hormonal therapies can be used to reduce the risk of breast cancer among women at high risk of the disease. These include the drugs tamoxifen for women older than 35 and raloxifene for postmenopausal women. These drugs have side effects, and women should discuss the benefits and risks with their doctors.
Women with a known harmful BRCA1 or BRCA2 mutation also have a higher risk of ovarian cancer and sometimes elect to have the ovaries removed to prevent ovarian cancer. Removing the ovaries also decreases the risk of breast cancer in women who have not reached menopause.
Women with early-stage breast cancer should talk to their doctors about the effect of family history on their own personal risk of a second breast cancer, as well as about risk-reducing strategies. Some women with a family history of breast and/or ovarian cancers might want to speak with a genetic counselor. A genetic counselor can talk about whether genetic testing for a BRCA1 or BRCA2 gene mutation might be appropriate. This information might help a woman decide on breast cancer treatment and risk-reducing approaches, including preventive mastectomy and hormone therapy.