Doctors recommend genetic testing only for women who have a strong family history of breast or ovarian cancer.

Testing might make sense for you if you fit any of these descriptions:

• You have 2 or more close relatives with breast or ovarian cancer, especially if 1 or more of the relatives were diagnosed with cancer before they turned 50. (Close family members include your mother, sister, or daughter, and can include men with breast cancer, such as your father, brother, or son.)
• You have a close family member with more than one cancer, such as cancer in both breasts, or cancer in the breast and the ovary.
• You have family members from different generations with breast or ovarian cancer. (For example, your grandmother, mother, and sister, all with cancer.) Family history on your father’s side is as important as your mother’s side.

Keep in mind, though, that having a strong family history of a disease does not always mean you have abnormal genes. Most women with a family history of breast or ovarian cancer do NOT have an abnormal gene.

If you are thinking about genetic testing because a family member has cancer, ask if she or he has been tested or is willing to be tested first. If the person with cancer does not have the mutation, it is less likely that you do.

In the US, most health insurance companies cover most of the costs. But your doctor or genetic counselor might need to write a letter to the insurance company to explain why you need testing.

If you test positive, try to stay calm. Finding out you carry a mutation can be scary. But there are ways to lower the chances that you will get cancer.

Ask your doctor and your genetic counselor what your results mean for you. Then ask what you can do to lower your chances of getting cancer.

If you test positive for any genetic mutation that might increase your cancer risk, tell your family about the results. It affects their health as well as yours. Some family members might also want to get tested.

There are some things you can do to lower your risk. Doctors have learned a lot about this by studying people with a BRCA mutation, and these options may apply to people with other mutations, too:

• Getting screened for breast and ovarian cancer often. This will not keep you from getting cancer, but it will increase the odds that you will find it early, when it is easier to treat.
• Having your breasts and ovaries removed. To lower your ovarian cancer risk as much as possible, experts suggest that the ovaries be removed as soon as you are done having children, and by age 40 if you have a BRCA1 mutation.
• Taking medicines that help prevent cancer
• Combining some or all of these choices