Trends in Contralateral Prophylactic Mastectomy for Unilateral Cancer: A Report From the National Cancer Data Base, 1998-2007

Background. Several studies have reported an increased rate of contralateral prophylactic mastectomy (CPM) in patients with unilateral breast cancer. This study reports on CPM trends from the American College of Surgeon's National Cancer Data Base (NCDB) diagnosed over a 10-year period. Methods. Data about women diagnosed with unilateral breast cancer between 1998 and 2007 undergoing CPM were extracted from the NCDB. Temporal trends were analyzed across patient demographic, tumor, and provider characteristics. Logistic regression models identified characteristics independently associated with use of CPM. Results. A total of 1,166,456 patients, of whom 23,218 patients underwent CPM, were reviewed; use increased from 0.4% in 1998 to 4.7% in 2007 of surgically treated patients. The greatest comparative increases in CPM was among white patients <40 years of age residing in high socioeconomic status areas with private or managed care insurance plans and treated at high-volume medical centers in the Midwest region of the country. A greater proportion of patients with in-situ disease undergo CPM compared to invasive disease. Independent factors associated with CPM include patient demographic and socioeconomic factors, tumor stage and histopathology, and provider characteristics. Conclusions. Although an increase in the proportion of surgically treated women undergoing CPM was universally observed across a broad range of patient, biological, and provider factors, the increase was more noticeably associated with patient-related factors rather than tumor or biological characteristics. Further studies are needed to determine why patients seem to choose CPM and whether a survival benefit can be associated with this choice of surgical management.