Is Breast Removal Best for BRCA Mutation?

July 1, 2003 -- Women with the breast cancer genes -- called BRCA1 and BRCA2 -- often face the decision of whether to have their breasts and ovaries removed to reduce the chance of cancer. But researchers say information about the benefits of these surgeries may be misleading.

Women with these inherited BRCA mutations have up to an 80% chance of developing breast cancer in their lifetime and up to a 40% chance of developing ovarian cancer.

Surgery to remove seemingly healthy breasts and ovaries is a drastic step, but some have supported it as a way to greatly reduce the chance of cancer linked to BRCA mutations. Though a new analysis shows that preventive surgery does greatly reduce cancer risk, investigators say how much is not clear.

Writing in the July 2 issue of the Journal of the National Cancer Institute, researchers from the Netherlands concluded that the available studies may be over- or underestimating the value of preventive mastectomy and ovary removal in women with BRCA mutations.

True Benefit Difficult to Determine

It is clear that the risk reduction is huge with these preventive surgeries, researcher Matti A. Rookus, PhD, of the Netherlands Cancer Institute, tells WebMD.

The problem lies in the fact that many women in the previous studies based their decisions about surgery on very personal, unique factors -- such as whether a close family member also had the surgery. This makes it difficult, the researchers say, to determine the true benefit of the surgery in other women with BRCAmutations.

Noah Kauff, MD, of Memorial Sloan-Kettering Cancer Center's Clinical Genetics Service, says it is clear that preventive surgery is the best way to prevent breast and ovarian cancers in women with BRCA mutations, but this does not necessarily make surgery the best option for all women.

He says ovary removal is strongly recommended for women with BRCA mutations once they don't want any more children. The best available evidence suggests that surgery reduces ovarian cancer risk by more than 90%.

Breast cancer risk also appears to be cut in half when ovaries are removed before menopause -- when the ovaries are still producing estrogen. Estrogen may influence breast cancer risk.

The true value of preventive mastectomy to reduce the risk of breast cancer is less clear. A woman still has a small chance of developing breast cancer even after breast removal because some breast tissue is left behind.

Questions still remain about the best way to reduce the risk of cancer in women with BRCA mutations. Current options include breast and/or ovary removal or drugs that counteract estrogen's effects on the breast, such as tamoxifen. Some also opt for intensive screening with mammography and breast exams to catch breast cancer in its early stages.

"It is true that there have been limitations in all of the studies that have been done to date," Kauff tells WebMD. "Because we don't have the right answer yet, all we can do is give women with these mutations the best information we have, and ultimately it is up to her to make a decision."