Triple-negative metaplastic breast cancer: treatment and prognosis by type of surgery.

BACKGROUND The role of surgery type in the prognosis of triple-negative metaplastic breast cancer (TN-MBC) patients remains controversial. Our study was designed to assess the role of surgery type in patient outcomes. MATERIALS AND METHODS Data from the Surveillance, Epidemiology, and End Results database were extracted to analyze patients with TN-MBC between 2010 and 2016. Kaplan-Meier analyses and multivariate Cox proportional models were used to estimate the prognoses. RESULTS We included 1,146 patients with a median follow-up time of 26 months (range 1-83 months). 470 (41.0%), 369 (32.2%), 244 (21.3%), and 63 (5.5%) patients underwent breast-conserving surgery (BCS), total mastectomy (TM), radical mastectomy, or no surgery. With the multivariate Cox analysis, the prognosis was related to age, TNM stage, and surgery type. With the Kaplan-Meier analysis, the more radical the operation, the worse the prognosis for the patients in the entire cohort. Within stage I-III disease, the best prognoses were observed in the patients undergoing BCS, followed by TM and radical mastectomy. The adjusted survival analysis showed that the prognoses of the patients undergoing BCS were better than the prognoses of the patients undergoing TM. Within stage IV disease, the patients who underwent an operation had a better prognosis regardless of the mode. CONCLUSION Patients undergoing BCS had the best prognoses among the patients with early and locally advanced TN-MBC. This improves our understanding of the clinicopathological and prognostic features of this rare entity but also provides more convincing therapeutic guidelines for TN-MBC.