Survey finds substantial use of CPM procedure among women with unilateral breast cancer

In a survey of women who underwent treatment for early-stage breast cancer in one breast, contralateral prophylactic mastectomy (CPM; both breasts are surgically removed, the breast that contains cancer and the healthy breast) use was substantial among patients without clinical indications but was low when patients reported that their surgeon recommended against it, according to a study published online by JAMA Surgery. Many patients considered CPM, but knowledge about the procedure was low and discussions with surgeons appeared to be incomplete.

Contralateral prophylactic mastectomy is a controversial procedure for patients with a diagnosis of unilateral breast cancer (cancer in one breast) because no compelling evidence suggests a survival advantage and the risk of contralateral breast cancer development is low for most patients. Yet celebrity exposure and publicity have recently drawn attention to this approach for the management of early-stage, unilateral breast cancer. Rates of this aggressive, costly and burdensome procedure are increasing, even among patients without a high genetic risk of a second primary breast cancer who would otherwise be candidates for breast-conserving therapy.

Little is known about treatment decision making or physician interactions in diverse patient populations.

Reshma Jagsi, M.D., D.Phil., of the University of Michigan, Ann Arbor, and colleagues conducted a survey of patients who underwent recent treatment for breast cancer to evaluate patient motivations, knowledge, and decisions, as well as the impact of surgeon recommendations. The survey was sent to 3,631 women with newly diagnosed unilateral stage 0, I, or II breast cancer between July 2013 and September 2014. Women were identified through the population-based Surveillance Epidemiology and End Results registries of Los Angeles County and Georgia. Data on surgical decisions, motivations for those decisions, and knowledge were included in the analysis.

Of the women selected to receive the survey, 2,578 (71 percent) responded and 2,402 of these respondents who did not have bilateral disease and for whom surgery type was known constituted the final analytic sample. Overall, 44 percent of patients considered CPM; only 38 percent of them knew that CPM does not improve survival for all women with breast cancer. Ultimately, 17 percent received CPM. Among 1,569 patients (66 percent) without high genetic risk or an identified mutation, 39 percent reported a surgeon recommendation against CPM, of whom only 12 (1.9 percent) underwent CPM, but among the 47 percent of these women who received no recommendation for or against CPM from a surgeon, 19 percent underwent CPM.

"When [patients] do not perceive a surgeon's recommendation against it, even patients without a high genetic risk for a second primary breast cancer choose CPM at an alarmingly high rate (nearly 1 in 5). However, CPM rates are very low among patients who report a surgeon's recommendation against it. Our findings should motivate surgeons to broach these difficult conversations with their patients, to make their recommendations clear, and to promote patients' peace of mind by emphasizing how other treatments complement surgery to reduce the risk of both tumor recurrence and subsequent cancer development," the authors write.

"These findings should also motivate efforts to inform and support surgeons in this challenging communication context, understand surgeons' perspectives more fully, and design physician-facing interventions to reduce excessive treatment."