Given that trend, researchers at the Duke Cancer Institute asked whether the decision to remove both breasts might result in a positive impact on women's quality of life if not their length of life.
Their study, reported online March 7 in the Journal of Clinical Oncology, found little evidence to support improved quality of life.
Contralateral prophylactic mastectomies (CPMs) were associated with slightly higher satisfaction in women's perception of how their breasts looked and felt, but primarily among women whose mastectomies were followed by reconstructive surgery.
"In our analysis, women who had CPM also reported marginally higher psychosocial wellbeing - feeling confident, emotionally healthy, accepting of their bodies," said senior author Shelley Hwang, M.D., chief of breast surgery at the Duke Cancer Institute. "But the differences between women who did and did not get CPM were very small and diminished over time. Psychosocial well-being continued to increase in both groups, even beyond 10 years after treatment."
Hwang and colleagues surveyed nearly 4,000 women who participated in the Army of Women, an organization committed to promoting patient engagement in breast cancer research. All the women had undergone either single or double mastectomies.
Using a well-validated patient-reporting tool called BREAST-Q, the researchers measured psychosocial, physical and sexual well-being. They also evaluated breast satisfaction, which focused on breast symmetry, appearance, feel, fit in a bra, and look in and out of clothing.
Women who elected to have CPM were generally younger, had higher incomes and earlier stage disease. Adjusting for those and other factors, the researchers found that the CPM group reported slightly higher breast satisfaction compared with the single-mastectomy group.
More important than CPM, however, was breast reconstruction, which had a much greater impact on quality of life. Reconstruction clearly resulted in much higher psychosocial well-being, breast satisfaction, and sexual well-being than CPM provided.
"Even though women imagine they will be much happier after CPM, we found that these patients' experiences are not greatly different from those of patients undergoing a single mastectomy," Hwang said. "CPM does not appear to translate into a much better quality of life in the way that breast reconstruction can."
Hwang said the findings provide additional insights that should help guide clinical decisions at a time when CPM is increasingly a choice women make, often out of fear that their cancer will return, but also for cosmetic reasons.
"The rate of CPM in women undergoing mastectomy for unilateral breast cancer has increased almost six-fold from 1998 to 2011 and now approaches 11 percent nationally," Hwang said.
She said the trend is predominantly driven by younger women with early-stage, unilateral breast cancer and no genetic risk factors. Many of these women might actually be eligible for breast-conserving surgeries instead of full mastectomies.
"This study supports what has concerned many of us -- that women are not benefiting as greatly from CPM as they expect they will," Hwang said. "Unless a woman has a gene mutation that places her at significantly increased risk of a new cancer in the other breast, CPM doesn't prolong life and our study shows that it doesn't make for a notably better quality of life."
Hwang said it's important for women to have a clearer understanding of the risks and benefits of the choices they are facing.
"The key to having long term satisfaction with treatment decisions is to review all the options and recognize the tradeoffs," Hwang said. "We need to continue to work hard to communicate these tradeoffs accurately and effectively with our patients."