The number of women diagnosed with breast cancer who undergo a double mastectomy is increasing. However, a new study questions the need for this procedure in most women. The study was published online on May 21 in the journal JAMA Surgery.
The study authors note that the increasing rate of a contralateral prophylactic mastectomy (double mastectomy for cancer prevention) among women diagnosed as having breast cancer has raised concerns regarding the potential for overtreatment. However, to date, few large studies regarding the factors that affect a women’s decisions for this procedure have been conducted. Therefore, they conducted a study to assess the factors associated with undergoing a contralateral prophylactic mastectomy among women with breast cancer.
The study group comprised 2,290 women who were newly diagnosed with breast cancer. The women were enrolled in the Detroit and Los Angeles Surveillance, Epidemiology, and End Results registries from June 1, 2005 through to February 1, 2007. Four years later (June 2009 through February 2010), the data was merged with Surveillance, Epidemiology, and End Results registry data (1,536 women). A statistical analysis was conducted to assess factors associated with type of surgery. The main variable factors included clinical indications for a contralateral prophylactic mastectomy (genetic mutation (i.e., BRCA1 or BRCA2) and/or a strong family history), diagnostic magnetic resonance imaging (MRI) findings, and the degree of worry expressed by the patient regarding breast cancer recurrence at the time of treatment decision making. The main outcome measurements were the type of surgery the patient underwent: contralateral prophylactic mastectomy, unilateral (single breast) mastectomy, or breast conservation surgery.
The investigators found that among the 1,447 women whose data was subjected to statistical analysis, 18.9% strongly a considered contralateral prophylactic mastectomy and 7.6% underwent one. Among the women who strongly considered a contralateral prophylactic mastectomy, 32.2% underwent one, 45.8% underwent a unilateral mastectomy, and 22.8% underwent breast conservation surgery. The majority of women (68.9%) who underwent a contralateral prophylactic mastectomy had no significant genetic or familial risk factors for contralateral disease (cancer in the opposite breast). Statistical analysis found that undergoing a contralateral prophylactic mastectomy (vs. either unilateral mastectomy or breast conservation surgery) was significantly associated with genetic testing, a strong family history of breast or ovarian cancer, undergoing an MRI, higher education, and greater worry about recurrence.
The authors concluded that many women considered a contralateral prophylactic mastectomy and a substantial number of then underwent one; however, only a small proportion of these women had a clinically significant risk of contralateral breast cancer. Undergoing an MRI when the breast cancer diagnosis was made increased the odds of undergoing a contralateral prophylactic mastectomy. Worry about breast cancer recurrence appeared to promote a decision to undergo a contralateral prophylactic mastectomy; however, the procedure has not been shown to reduce recurrence risk. The researchers recommended that further research should be conducted regarding the underlying factors driving the use of a contralateral prophylactic mastectomy.
The study authors are affiliated with the Ann Arbor Healthcare System (Ann Arbor, Michigan), University of Michigan Medical School (Ann Arbor, Michigan), University of Michigan School of Public Health (Ann Arbor, Michigan), Memorial Sloan Kettering Cancer Center (New York, New York), University of Southern California (USC; Los Angeles, California), and Rutgers Cancer Institute of New Jersey (New Brunswick, New Jersey).
Take home message:
The decision to undergo a contralateral prophylactic mastectomy should only be made after a thorough discussion with one’s physician. A contralateral prophylactic mastectomy decreases the risk of recurrence; however, it does not totally eliminate it because a small amount of breast tissue may remain after the procedure.The UCLA Breast Reconstructive Center offers full range of options to meet every patient's needs