Meta-analysis to determine if surgical resection of the primary tumour in the setting of stage IV breast cancer impacts on survival.

Introduction: 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.

Methods: 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.

Results: 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.

Conclusions: 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.