Introduction  Patients with unilateral breast cancer have an increased risk of developing contralateral breast cancer. A recent population-based study demonstrated that the proportion of patients with unilateral breast cancer in the United States who underwent contralateral prophylactic mastectomy (CPM) has increased by 150% in recent years. The current study evaluated patients who underwent breast cancer surgery in a metropolitan-based hospital system to determine factors associated with CPM.

Methods  We reviewed the records of all patients who underwent surgical treatment for breast cancer in 2006 and 2007 in a single health care system, which included six different hospitals. Exclusion criteria included preoperative diagnosis of bilateral disease, stage IV disease, and a history of previous breast cancer. We recorded patient, treatment, tumor, and surgeon characteristics. Multivariate logistic regression models were used to predict CPM use.

Results  Of 571 eligible patients, 276 (48.3%) underwent breast-conserving surgery (BCS), 130 (22.8%) underwent unilateral mastectomy, and 165 (28.9%) underwent mastectomy and a CPM. Among mastectomy patients, 55.9% underwent CPM. Young age (<40 vs. >55 years), large tumor size (>5 vs. <2 cm), positive family history, lobular histology, multicentric disease, and surgeon gender (female) were independent predictors of increased CPM rates. Body mass index, tumor grade, estrogen receptor status, and preoperative breast magnetic resonance imaging were not associated with increased CPM rates.

Conclusions  Our study is the first to evaluate specific surgeon characteristics associated with CPM use. Prospective studies are needed to examine factors affecting patient decision-making to develop resources that may assist patients in this process.