Breast Removal Protects Women at High Risk

B O S T O N, July 18, 2001 -- For women with strong family histories of breast cancer, deciding how to handle the risk is an extremely difficult and life-altering process.

A new study reported in Thursday's issue of the New England Journal of Medicine might now make that decision easier — and harder.

Dutch researchers have found that for women who carry particular genetic mutations, removing both breasts greatly reduces the risk of developing breast cancer. The procedure, called bilateral prophylactic mastectomy, protects a woman by removing breast tissue that could potentially become cancerous in the future.

All of the women in the study carried mutations in either the BRCA 1 or BRCA 2 genes (BRCA = breast cancer), which have been shown to make carriers five to seven times more at risk for developing breast cancer.

Of 139 BRCA1/2 positive women — that is with either or both gene mutations — followed for three years, eight out of 63 (13 percent) women who did not have mastectomies developed breast cancer, whereas all 76 women who had both breasts removed remained cancer free.

Up to 85 Percent Chance of Breast Cancer

"Although the follow-up time is relatively short and the findings can be applied only to women who carry these genes, the study is very well done," said Dr. Alison Estabrook, chief of breast surgery at St. Luke's Roosevelt Medical Center in New York. "Based on these results, we can now almost guarantee women positive for BRCA1/2 mutations who choose prophylactic mastectomies that they will not get cancer within three years."

Breast Cancer Symptoms and Treatment

Without any medical intervention, BRCA 1/2-positive women have a 55 percent to 85 percent chance of getting breast cancer within their lifetime. Moreover, their chances of developing ovarian cancer are also increased, by as much as 65 percent for those most at-risk. Fortunately, these gene mutations are quite rare and carried only by one in every 800 to 1,000 American women.

"Overall, only about 5 to 10 percent of all breast cancer is genetically related," says Dr. Katherine Lee, breast cancer surgeon and prevention specialist at the Cleveland Clinic. "The majority of patients have no family history, however the average age of onset for non-genetically linked breast cancer is about 60 years old, whereas for genetically linked forms the onset is much faster, at about 42 years."

For a woman to have her breasts removed, of course, can be a traumatic experience. Doctors said that about 50 percent of women with the gene mutation in the study had both breasts removed, but in the larger population in the United States only about a quarter of such women elect to remove both breasts.

Often the women who have breasts removed — often at a young age, for example in their 20s — have watched their mothers and perhaps other close relatives die of breast cancer.

Breast Exams Recommended

The American Cancer Society reports breast cancer to be the second most common cancer among women, taking the lives of more than 40,000 women in the United States each year. It is estimated that the average woman has a 1 in 8 chance of getting breast cancer within her lifetime, and almost 200,000 new cases of breast cancer will be diagnosed in the United States in 2001.

"Women who have more than one relative with breast or ovarian cancer are at higher risk for developing breast cancer and should discuss their family histories in detail with their physicians to decide whether genetic testing and/or prophylactic treatments should be begun," advises Dr. Lynn Hartmann of the Mayo Clinic. Hartman is a leading medical oncologist and author of a highly regarded 1999 study showing the benefits of prophylactic mastectomy.

Hartmann and other cancer experts agree that all women should protect themselves by performing monthly breast self-exams, getting yearly physicals, and starting annual mammogram screening at the age of 40.

The doctors also emphasize that double mastectomies are not the only effective treatment choice for women at very high risk, or even for those who already have breast cancer.

Other treatment options include the removal of both ovaries — called prophylactic oophorectomy — and chemotherapy drugs such as Tamoxifen and Raloxifene, which can reduce the risk of breast cancer by up to 50 percent. Another strategy for high-risk women is to simply "watch-and-wait" under the care of a physician.

As yet, there are no studies that directly compare all treatment options available, making a woman's choice all the more complicated.

It is recommended that high-risk patients discuss the costs and benefits of each option with their doctor while considering family history, medical status, and personal values.