Bilateral Mastectomy for Unilateral Breast Cancer: a Perplexing Trend

Abstract

In the United States, there has been a trend towards the increased utilization of bilateral mastectomy for the treatment of unilateral breast cancer. Yet, breast conserving surgery rates have increased slightly, so it is among women choosing mastectomy that the use of bilateral mastectomy is increasing. Ironically, since about 1985, the risk of developing contralateral breast cancer has decreased, likely due to the widespread use of adjuvant systemic therapy for the treatment of early breast cancer. The increased utilization of bilateral mastectomy is therefore puzzling, and this article discusses factors that may account for this trend. Several observational studies have shown that bilateral mastectomy is associated with improved survival when compared to unilateral mastectomy. However, these associations are probably due to selection bias, and bilateral mastectomy is unlikely to have an independent effect in improving survival for the majority of women with unilateral breast cancer. Bilateral mastectomy might be indicated for women with a high risk of developing contralateral breast cancer, such as those with a history of mantle irradiation or mutations in the BRCA 1 or BRCA 2 genes, but it cannot be entirely justified in the majority of women with unilateral breast cancer. Keywords Breast cancer . Contralateral prophylactic mastectomy . Bilateral mastectomyThe use of bilateral mastectomy for the treatment of unilateral breast cancer is increasing rapidly. In the United States, this perplexing trend began in the late 1990s, was first reported in 2007, and has now been observed in other parts of the world as well [1][2][3]. Surprisingly, during this same period, the use of breast conserving surgery (lumpectomy) in the United States has slightly increased [4]. Thus, among women choosing mastectomy, there is a trend towards increased utilization of bilateral mastectomy rather than unilateral mastectomy. The surgical treatment of unilateral breast cancer is therefore becoming increasingly polarized; large numbers of women are choosing either lumpectomy or bilateral mastectomy, while the use of unilateral mastectomy is declining. The removal of the opposite uninvolved breast in women with unilateral breast cancer is often referred to as Bcontralateral prophylactic mastectomy (CPM)^. In this article, BCPM^will refer to bilateral mastectomy in women with unilateral breast cancer. This review discusses CPM, its implications, and possible underlying factors responsible for its increased utilization.In 2007, Tuttle et al. reported that the overall rate of CPM in the United States increased from 1.8 % in 1998 to 4.5 % in 2003, based upon analysis of the Surveillance, Epidemiology, and End Results (SEER) database [1]. These investigators subsequently reported that the overall rate of CPM had also increased for women with ductal carcinoma in situ (DCIS), from 2.1 % in 1998 to 5.2 % in 2005 [5]. Yet, the overall rate of mastectomy in the United States decreased from 40.8 % in 2000 to 37 % in 2006 (when mastectomy ra...