Meta-Analysis to Determine if Surgical Resection of the Primary Tumour in the Setting of Stage IV Breast Cancer Impacts on Survival

The role of primary tumor excision in patients with stage IV breast cancer is unclear. Therefore, a meta-analysis of relevant studies was performed to determine whether surgical excision of the primary tumor enhances oncological outcome in the setting of stage IV breast cancer. A comprehensive search for relevant published trials that evaluated outcomes following excision of the primary tumor in stage IV breast cancer was performed using MEDLINE and available data were cross-referenced. Data were extracted following review of appropriate studies by authors. The primary outcome was overall survival following surgical removal of the primary tumor. Data from ten studies included 28,693 patients with stage IV disease of whom 52.8 % underwent excision of the primary carcinoma. Surgical excision of the primary tumor in the setting of stage IV breast cancer was associated with a superior survival at 3 years (40 % (surgery) versus 22 % (no surgery) (odds ratio 2.32, 95 % confidence interval 2.08-2.6, p < 0.01). Subgroup analyses for selection of patients for surgery or not, favored smaller primary tumors, less competing medical comorbidities and lower metastatic burden (p < 0.01). There was no statistical difference between the two groups regarding location of metastatic disease, grade of tumor, or receptor status. Patients with stage IV disease undergoing surgical excision of the primary tumor achieve a superior survival rate then their nonsurgical counterparts. In the absence of robust evidence, this meta-analysis provides evidence base for primary resection in the setting of stage IV breast cancer for appropriately selected patients.