For the majority of women, the risk of contralateral breast cancer is very low. We want them to know that [prophylactic mastectomy] is not a risk-free operation.
—Fahima Osman, MD
A retrospective analysis of a large surgical database has documented that bilateral mastectomy is associated with a doubling in complication rates, compared with unilateral mastectomy. Researchers reported the findings at the 14th Annual Meeting of the American Society of Breast Surgeons in Chicago.1
Recent studies have shown that women with unilateral breast cancer are choosing contralateral prophylactic mastectomy at an increasing rate despite the well-established evidence of a low risk for future contralateral breast cancer and no strong evidence supporting a survival benefit. (There is evidence showing benefit, however, that evidence is not strong.) With the exception of a minority of high-risk patients who benefit from risk reduction with contralateral prophylactic mastectomy, there is evidence suggesting that the majority of women choose contralateral mastectomies based on fear of recurrence and a perceived survival benefit, said Fahima Osman, MD, a fellow at the University of Toronto.
“For the majority of women, the risk of contralateral breast cancer is very low. We want them to know that this is not a risk-free operation. Removing a healthy breast is associated with complications,” Dr. Osman said.
Few studies have evaluated the postoperative complication rates associated with contralateral prophylactic mastectomy without breast reconstruction. Using data from the American College of Surgeons Surgery Quality Improvement Program (ACS NSQIP) Participant Use Data Files from 2007 to 2010, Dr. Osman and colleagues compared patients with breast cancer undergoing unilateral mastectomies to those with bilateral mastectomies. Both groups had unilateral sentinel lymph node biopsy, and none had immediate reconstruction.
“We wanted to estimate the risk of complications in low-risk patients. We used several exclusion criteria to create a group of patients that had low operative risk factors. Despite that selection of low-risk patients, we found increased complications associated with bilateral mastectomies. The complication rate can potentially be higher if a reconstruction procedure is added,” she told The ASCO Post. “It makes sense that more operations can translate into more potential for complications.”
Large Database Probed
The study identified 4,219 patients who underwent sentinel lymph node biopsy, of whom 3,722 (88.2%) had a unilateral mastectomy and 497 (11.8%) a bilateral mastectomy. Wound and infectious complications were significantly higher in the bilateral mastectomy group. The overall 30-day complication rate was nearly doubled: 7.6% vs 4.2%, for an unadjusted odds ratio of 1.9 (P < .05), Dr. Osman reported.
The wound complication rate (infection and wound dehiscence) was 5.8% for the bilateral group vs 2.9% in the unilateral group, for an unadjusted odds ratio of 2.1 (P < .05). Infectious complications occurred in 2.2% vs 0.8% (P < .05).
In the multivariable analysis, which accounted for a number of preoperative risk factors, bilateral mastectomy still carried an odds ratio for overall postoperative complications of 1.9 (P = .001). Independent predictors were body mass index (on a continuous scale; average, 29.1 kg/m2) (odds ratio = 1.05; P < .001) and smoking (odds ratio = 2.21; P < .001).
‘Deal With the Cancer First’
When a woman with unilateral breast cancer and a low risk of developing contralateral breast cancer insists on having mastectomies simultaneously, Dr. Osman tries to discourage that. “It is always best to deal with the cancer first,” she said.
After patients have “digested the news of the cancer diagnosis,” she discusses the actual risk vs the patient’s perceived risk of a second breast cancer and the risks associated with contralateral prophylactic mastectomy. “I tell them we need to concentrate on treating the primary tumor and not take a risk on delaying chemotherapy and radiation due to complications. I would also advise patients with high preoperative risk factors such as smoking and obesity to look at these risks carefully. It is important that we, surgeons discuss these complication rates with patients contemplating contralateral prophylactic mastectomy. ■
Disclosure: Dr. Osman reported no potential conflicts of interest.
1. Osman F, Saleh F, Corrigan M, et al: Increased postoperative complications in bilateral mastectomy patients compared to unilateral mastectomy: An analysis of NSQIP data. American Society of Breast Surgeons Annual Meeting. Abstract 0167. Presented May 3, 2013.