The number of women undergoing double mastectomies has increased significantly over the past 10 years even though no new evidence has suggested that this procedure offers additional survival benefits, according to a new study

"Our analysis highlights the sustained, sharp rise in popularity of CPM while contributing to the mounting evidence that this more extensive surgery offers no significant survival benefit to women with a first diagnosis of breast cancer," senior author Mehra Golshan said. "Patients and caregivers should weigh the expected benefits with the potential risks of CPM including prolonged recovery time, increased risk of operative complications, cost, the possible need for repeat surgery, and effects on self image."

Researchers at Brigham and Women's Hospital in Boston, Mass., examined the rate of contralateral prophylactic mastectomy (CPM), which involves surgically removing a breast that has not been affected by cancer. They examined 496,488 female patients who were diagnosed with unilateral stage-one to stage-three breast cancer.

Over the course of 8.25 years, 59.6 percent of the participants had undergone breast-conserving surgery, 33.4 percent had a unilateral mastectomy and seven percent opted for CPM. When analyzing CPM rates specifically, the researchers found that the number of CPM procedures has tripled from 3.9 percent in 2002 to 12.7 percent in 2012.

The team then compared the survival rates in women who had breast-conserving surgery to those who had CPM and found that CPM did not lead to any significant increases in survival rates. Despite no difference in survival benefits, the researchers found that women who chose CPM appeared to do so in order to increase their lifespan.

"Women with unilateral breast cancer undergoing CPM continue to report a desire to extend life as one of the most important factors leading to their surgical decision," Golshan added. "Understanding why women choose to undergo CPM may create an opportunity for health care providers to optimally counsel women about surgical options, address anxieties, discuss individual preferences and ensure peace of mind related to a patient's surgical choice."

The researchers stressed the importance of informing women about these different procedures and their effects on survival rates. They did note that for women with a genetic mutation or a family history of breast cancer, CPM could potentially provide additional survival benefits. 

The study was published in the March 11 issue of the journal Annals of Surgery.