The professional oncology community has worked diligently to generate data that facilitate surgical planning and the decision-making process for patients with newly diagnosed breast cancer. Several lines of evidence support the importance of prioritizing treatment of the known cancer over and above consideration of a risk-reducing mastectomy for the unaffected breast (contralateral prophylactic mastectomy [CPM]). For example, the equivalent overall survival for breast-conserving surgery (BCS) and mastectomy makes CPM an unnecessary option for women who are eligible for lumpectomy and desire breast preservation. Incidence of metachronous contralateral breast cancer (ie, contralateral cancer detected several months after initial breast cancer diagnosis) is relatively low, at 0.25% to 1% per year,1,2 and these cancers are usually detected at early, highly curable stages. Synchronous occult contralateral breast cancer is uncommon, as documented by studies revealing incidental cancer in only 1% to 3% of CPM specimens.3,4 Survival is comparable for patients with unilateral vs metachronous bilateral breast cancer5,6 and typically is associated with the stage of first cancer, consistent with the concept that the initially presenting tumor has a lead-time advantage in establishing distant organ micrometastases.
Newman LA. Contralateral Prophylactic MastectomyIs It a Reasonable Option?. JAMA. 2014;312(9):895-897. doi:10.1001/jama.2014.11308