MONDAY, Feb. 23, 2004 (HealthDayNews) -- Women at high risk for breast cancer who have a preventive double mastectomy reduce the risk of developing the disease by 90 percent, new research says.
These new findings relate specifically to women who have the BRCA1 or BRCA2 mutation, which puts them at a greatly increased risk of developing breast (and ovarian) cancer over their lifetime. Some 3 percent to 10 percent of breast cancers are thought to be related to these genetic mutations.
"This is a first-class paper," says Dr. Jay Brooks, chief of hematology/oncology at the Ochsner Clinic Foundation in New Orleans. "This clearly gives tremendous direction to physicians, in my opinion, on how to handle BRCA 1 and 2 positive patients."
Nevertheless, the decision to undergo such a procedure is not one to be taken lightly.
"[The findings are] good news on the clinical risk-reduction side of things," says Timothy R. Rebbeck, co-program leader of the Cancer Epidemiology and Risk Reduction Program at the University of Pennsylvania's Abramson Cancer Center. "Clearly, if you have prophylactic mastectomy, you'll eliminate most of the breast cancer risk and that's good. [But] most people have not studied the psychosocial, behavioral and other implications of that surgery, and that's not trivial."
Rebbeck is lead author of the study outlining the new findings, which appear in the March 15 issue of the Journal of Clinical Oncology.
Although some women with the BRCA1 and BRCA2 mutations do elect to have prophylactic mastectomies, there is little data on how effective the strategy is. According to Rebbeck, there really are no other effective options for lowering risk. This is the first study to quantify the risk reduction related to the procedure.
The study followed 483 women with BRCA1 and BRCA2 mutations from 11 sites in North America and Europe for six years. Women who chose to have prophylactic mastectomies were compared with women with the mutations who did not have the procedure.
Two of the 105 women who had double mastectomies (1.9 percent) developed breast cancer, while 184 of the 378 controls (48.7 percent) were diagnosed with the disease. Double prophylactic mastectomies reduced the risk of breast cancer by about 90 percent in women who kept their ovaries and by about 95 percent in women who also had their ovaries removed.
Rebbeck says he was not surprised by the findings. "If you remove the vast majority of tissue that's at risk, you would expect the risk to go down -- and that's what we saw," he says. The two women in the mastectomy group who developed breast cancer both had subcutaneous mastectomies, meaning some of the breast tissue and nipple were preserved.
"Many women are actually using these surgeries, and their clinicians are suggesting that they have it," Rebbeck says. "Now, women will have actual numbers to work from to make these decisions. No matter what the ultimate decision is, they have to be made on a personal level. There can't be a global recommendation, but now at least there'll be data."
Still, the holy grail is to find a nonsurgical way to reduce risk. The paper points out that most of the study participants in North America refused to have a bilateral mastectomy.
"That is a very important finding because what we have to do is find a way to reduce the risk nonsurgically," says Dr. Julia A. Smith, a clinical assistant professor of medicine at New York University School of Medicine in New York City. "Surgery can be very effective, but it is a very gross and crude attack on cancer."
She adds, "What we need is much more refined, where we're attacking at the cellular and molecular level to prevent or reverse early changes so that we don't have to decimate the organ as a preventive strategy."