Outcomes of partial mastectomy in male breast cancer patients: analysis of SEER, 1983-2009.

BACKGROUND: Although mastectomy is considered the gold standard for male breast cancer (MBC), the utilization of lumpectomy and its impact on outcomes in MBC patients has not been previously studied.
METHODS: The Surveillance, Epidemiology and End Results (SEER) database was used to identify all MBC patients who underwent either mastectomy or less than mastectomy (i.e., lumpectomy) between 1983 and 2009.
RESULTS: A total of 4707 (86.8 %) men underwent mastectomy and 718 (13.2 %) underwent lumpectomy. A greater proportion of patients underwent lumpectomy later in the study period (1983 to 1986, 10.6 %, vs. 2007 to 2009, 15.1 %). A greater percentage of lumpectomy patients were 80 years or older (21.3 % vs. 16.3 %), had stage IV disease (7.3 % vs. 3.1 %), and received no lymph node sampling (34.3 % vs. 6.9 %). Only 35.4 % of patients underwent adjuvant radiotherapy after lumpectomy. Ten-year breast cancer-specific survival and overall survival were 82.8 % and 46.9 %, respectively, in lumpectomy patients vs. 77.3 % and 46.4 %, respectively, in mastectomy patients. On Cox proportional hazards regression, lumpectomy was not independently associated with worse breast cancer-specific survival (odds ratio 1.09, 95 % confidence interval 0.87-1.37) or overall survival (odds ratio 1.12, 95 % confidence interval 0.98-1.27) after controlling for age, race, stage, and grade, as well as whether radiotherapy was received.
CONCLUSIONS: Lumpectomy is performed in a small but growing proportion of MBC patients. These patients are not only older and more likely to have advanced disease at the time of diagnosis, but they also are less likely to receive standard of care therapy, such as lymph node sampling and adjuvant radiotherapy. Despite these observations, breast cancer-specific survival is unaffected by the type of surgery.