Contralateral prophylactic mastectomy more common in US

Nearly half of American women diagnosed with breast cancer who are BRCA1 or BRCA2 mutation carriers elect prophylactic contralateral mastectomy, but the acceptance of such preventive surgery is much lower in Europe, according to research published online Jan. 14 in advance of publication in the Journal of Clinical Oncology.

Canadian investigators followed an international cohort of 927 women with unilateral breast cancer and BRCA1/BRCA 2 mutations for a minimum of 1.5 years to evaluate the frequency of and factors predicting prophylactic contralateral mastectomy.

In total, 253 women (27.3%) underwent prophylactic contralateral mastectomy after an initial diagnosis of cancer. Rates of contralateral mastectomy varied greatly by country, ranging from 0% in Norway to 49.3% in the United States. Among North American women, those undergoing prophylactic mastectomy were younger (mean age, 39 years) than those without preventive surgery (mean age, 43 years). In addition, prophylactic contralateral mastectomy was more common in women who elected initial mastectomy versus breast-conserving surgery, and in women who underwent prophylactic bilateral oophorectomy compared to those with intact ovaries.

"Age, type of initial breast cancer surgery, and prophylactic oophorectomy are all predictive of prophylactic contralateral mastectomy in women with breast cancer and a BRCA mutation. The acceptance of contralateral preventive mastectomy was much higher in North American than in Europe," the authors conclude.

Metcalfe KA, Lubinski J, Ghadirian P, et al. Predictors of contralateral prophylactic mastectomy in women with a BRCA1 or BRCA2 mutation: the Hereditary Breast Cancer Clinical Study Group. J Clin Oncol. [Published online ahead of print January 14, 2008.] J Clin Oncol. 2008;26:1083-1097. doi:10.1200/JCO.2007.12.6078.