High-Risk Women May Benefit From Preventive Surgery

Women with BRCA gene mutations can benefit from having healthy ovaries removed. So says the largest study of its kind, published September 1 in the Journal of the American Medical Association. Women with these gene mutations have 10 times the risk of ovarian cancer, compared with the general population. The study included about 2,500 women. About 4 in 10 had their ovaries removed. Over the next four years, these women had lower risks of ovarian and breast cancer, compared with similar women who did not have the surgery. They also had a lower risk of dying. The Associated Press wrote about the study September 1.

What Is the Doctor's Reaction?

There is justified excitement about recent advances in our understanding of genes in health and disease. Surely, a better understanding of our genes will lead to significant medical progress.

But many have wondered how soon these advances will become useful. After all, it's one thing to map the human genome. It's quite another to apply that information to prevent illness or treat disease. For many conditions, there is little one can do to avoid disease based on the results of a genetic test.

Genetic testing can be useful for parents concerned about the health of their future children. And a few genetic tests are available to guide disease treatment. But considering the amount of information we have about the human genome, there are relatively few examples of genetic testing leading directly to health benefit.

Genetic testing for BRCA mutations has become increasingly common. These genetic variants are associated with a markedly increased risk of developing cancer of the ovaries and breast. The lifetime risk of these cancers is so high – up to 84% for breast cancer and 40% for ovarian cancer - that some women who carry BRCA mutations decide to have preventive surgery, including mastectomy and removal of the ovaries.

A new study demonstrates that having preventive surgery is beneficial for women who carry BRCA mutations. Among nearly 2,500 women with these mutations:

• Mastectomy was associated with no cases of breast cancer for at least 3 years after surgery. Meanwhile 7% of BRCA carriers who did not have mastectomy developed breast cancer during the same time period.

• Ovary removal was associated with no cases of ovarian cancer for 6 years after surgery. Three percent of otherwise similar women who did not have surgery developed ovarian cancer.

• Ovary removal appeared to reduce the risk of death due to ovarian cancer, breast cancer or any cause.

Why is this important? If confirmed, these findings can provide guidance to women faced with these important questions:

• Why is it important to consider testing for BRCA genes?

• If BRCA testing is offered, should I have it?

• What are my options if testing shows that I carry a BRCA mutation?

Having relevant information about the impact of treatment decisions based on genetic information could help you and your doctor discuss these questions.

What Changes Can I Make Now?

This study looks at whether surgery to prevent breast and ovarian cancer is useful among women who have BRCA gene mutations. However, these genetic mutations are relatively rare. They affect just 1 in 500 women and account for just 5 to 15% of these cancers. So, it's important for every woman, not just those at with these mutations, to do what they can to reduce her risk of breast or ovarian cancer.

The following may reduce your risk of breast cancer:

• Keep your weight in a healthy range

• Exercise regularly

• Breastfeed your baby

• Don't use hormone-replacement therapy (or if you do, take the lowest effective dose for the shortest possible time)

• Don't smoke

• Moderate your alcohol consumption

The risk of ovarian cancer may be lower among women who:

• Use birth control pills (although the pill may increase the risk of breast cancer among women who carry a BRCA mutation)

• Have a tubal ligation (although the reason is not known)

• Become pregnant and breastfeed their babies

• Choose a low-fat, high fiber diet; reducing meat and alcohol consumption may also help

Consider having a test for the BRCA mutation. Testing is recommended for women in these categories:

• Women with strong family history of breast cancer, ovarian cancer or both, especially in close relatives who had cancer before age 50.

• Women with at least one relative known to carry a BRCA mutation.

You may wonder why genetic testing for the BRCA mutation is not recommended for every woman. The reason is that given the rarity of this mutation, it's quite unlikely to detect a mutation unless your family history suggests that you may be a carrier.

What Can I Expect Looking to the Future?

You will undoubtedly hear more about genetic testing in the near future. Such testing will provide results that are more than just interesting. They will increasingly guide medical care and decision making in ways that actually improve health. Although we must be patient, I think the day will soon come when genetic testing will become routine and it will be common that the results direct more effective medical care.