Breast Removal Protects Women at High Risk

B O S T O N, July 18 -- 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."