More Breast Cancer Patients Choosing Preventive Mastectomy, Despite Low Rates of Cancer Recurrence

Many more breast cancer patients are opting to remove their healthy breast, despite the fact that a double mastectomy doesn't increase survival rates. REUTERS/Jim Bourg

A disproportionate number of breast cancer patients who undergo a mastectomy also choose to remove their healthy breast—a procedure called contralateral prophylactic mastectomy—despite a large body of research that shows the risk for disease recurrence is extremely low. According to a new study published March 11 in Annals of Surgery, rates of CPM have more than tripled in a decade.

Less than 1 percent of breast cancer survivors experience a recurrence of the disease in their unaffected breast at a later point. And for most women who have a second breast cancer diagnosis, the disease is typically caught before it becomes invasive. Studies have shown that CPM can benefit breast cancer patients with mutations to the BRCA 1 and BRCA 2 genes—mutations that raise the overall risk for breast cancer by as much as 85 percent. However, for women who do not have a genetic risk for the disease, the surgery is likely to be unnecessary.

For the study, researchers analyzed data from 2002 to 2012 on nearly 500,000 women from the Surveillance, Epidemiology and End Results (SEER) database, a national cancer registry. All of the women had stage one to three breast cancer in just one breast. They followed these women for just over eight years. Most of the women underwent lumpectomy or breast-conserving therapy (59.6 percent overall); mastectomy of just the unhealthy breast (33.4 percent); or CPM (7 percent).

The researchers noticed some alarming trends in the data. Most notably, the number of women opting for CPM increased from 3.9 percent in 2002 to 12.7 percent in 2012. Rates of survival and cancer recurrence didn't improve for women who opted for CPM versus unilateral mastectomy or breast-conserving surgery.

The researchers also found that in the same period the rates of breast reconstruction surgery also increased— from 35.3 percent to 55.4 percent during the study period. (This may be partly due to the Women's Health and Cancer Rights Act, passed in 1998, which made it mandatory for insurance companies to cover the cost of breast reconstruction surgery as part of treatment.)

Some people point to the "Angelia Jolie effect" to explain why more women with breast cancer or a higher risk for the disease are choosing double mastectomy when alternatives are much less invasive and often have the same long-term health outcomes. In 2013, the actress went public with her decision to undergo a double mastectomy after learning she tested positive for BRCA gene mutations.

But Dr. Mehra Golshan, a distinguished chair in surgical oncology at Brigham and Women's Hospital and senior author of study, says that the number of CPM surgeries has been increasing steadily, as noted by a landmark paper published in 2007 in the Journal of Clinical Oncology. That study, also based on SEER data, found rates of CPM increased from 4.2 percent in 1998 to 11 percent in 2003, suggesting the trend had already been occurring by the time Jolie made her announcement.

Golshan says reconstructive surgery has improved dramatically in the past decade. In many cases, a surgeon can preserve the nipple and areola and take skin grafts from elsewhere on the body to reconstruct the breast. Some studies have suggested that women who choose CPM may be concerned about breast asymmetry or wish to use the reconstructive surgery to improve their overall appearance.

But there are downsides to these procedures. Women who undergo mastectomy and reconstructive surgery lose sensation in their breast, which can be psychologically distressing. Patients who opt for CPM are unable to nurse a child in the future, which is often a consideration for women of childbearing age.

Golshan says too many women make their decision without enough information and at a time when fear of cancer recurrence is overwhelming. "When we have those talks with the patients, we have to be able to articulate to them what is true and what isn't," he says. " Worrying about a perceived cancer in the normal breast doesn't make a lot of sense to me." He suggests that more research is needed to figure out the best way to counsel patients to make fully informed decisions.