The discovery of BRCA1, BRCA2 and other genes that may increase breast cancer risk has raised a number of emotional and legal questions about genetic testing. A simple blood test can help identify defective BRCA genes, but it's not 100 percent accurate and most experts believe that only women at high risk of hereditary breast or ovarian cancers should be referred for testing. If you're one of these women, it's important to know that having a defective BRCA gene doesn't mean you'll get breast cancer. In addition, test results cannot determine how high your risk is, at what age you might develop cancer, how aggressively the cancer might progress or what your risk of death may be.

In general, testing is most beneficial if the results of the test will help you make a decision about how you might best reduce your chance of developing breast cancer. Options range from lifestyle changes and closer screening and therapy with medications such as tamoxifen to extreme measures such as preventive (prophylactic) bilateral mastectomy and removal of your ovaries (oophorectomy). These can be wrenching decisions for any woman to make. Be sure to thoroughly discuss all your options with a genetic counselor, who can explain the risks, benefits and limitations of genetic testing. It can also help to talk to other women who have had to make similar decisions.