Local Surgery Improves Survival in Patients with Primary Metastatic Breast Cancer: A Population-Based Study.

The clinical value of local surgery in the breast cancer patients with distant metastasis is still unclear. A total of 8,922 primary metastatic breast cancer patients from the Surveillance, Epidemiology, and End Results (SEER) database were analyzed in the current study. Primary outcome variables included breast cancer-specific survival (BCSS) and overall survival (OS). Among the patients, 1,724 (19.3%) who underwent surgical treatment (ST) of primary breast tumor had increased OS (p < 0.001) and BCSS (p < 0.001) compared with those in the nonsurgical treatment (NST) group. Multivariate analysis revealed that surgery improved survival and was an independent prognostic factor for OS (hazard ratio [HR] = 0.617; 95% confidence interval [CI], 0.562-0.676, p < 0.001) and BCSS (HR = 0.623; 95% CI, 0.565-0.686, p < 0.001). Further result showed that ST tended to prolong the survival of patients with 1 or 2 distant metastatic sites (p < 0.05 for OS, p < 0.05 for BCSS). However, no differences were found in prognostic outcomes between different surgical procedure groups (p = 0.886 for OS, p = 0.943 for BCSS). In conclusion, our study suggested that local surgery appeared to confer a survival benefit, which may provide new understanding of treatment for these patients.