The impact of liver resection on survival for patients with metastatic breast cancer – A systematic review and meta-analysis

Introduction: There is uncertainty surrounding the role of resection as an option for curative treatment of breast cancer with liver metastases (BCLM). Aim: To perform a systematic review and meta-analysis evaluating the role of liver resection for BCLM. Methods: A systematic review was performed as per PRISMA guidelines. Hazard ratio (HR) for overall survival (OS) and standard error was obtained from each study and expressed using the generic inverse variance method, with a corresponding 95% confidence interval (CI). OS outcomes at 1- 3- and 5-years were expressed as dichotomous variables and pooled as odds ratios (OR) using the Mantel-Haenszel method. Results: Nine studies with 1732 patients were included. Of these, 24.5% underwent surgical resection of BCLM (424/1732) and 75.5% did not (1308/1732). Overall, OS was significantly better among those who underwent surgery versus controls (HR: 0.69, 95% CI: 0.59–0.80, P < 0.00001). Mortality rates were significantly reduced at 1-year (7.5% (10/134) vs 20.3% (79/390), OR: 0.25, 95% CI: 0.08–0.74, P = 0.010) and 5-years (54.0% (190/352) vs 75.3% (940/1249), OR: 0.46, 95% CI: 0.25–0.87, P = 0.020) respectively for those undergoing surgery versus controls. Mortality rates at 3 years after surgery were lower than the control group (19.1% (29/152) vs 53.0% (222/419)), however this failed to achieve statistical significance at meta-analysis (OR: 0.32, 95% CI: 0.09–1.12, P = 0.070). Conclusion: Liver resection may be considered at multidisciplinary meetings for those with BCLM and offers a potentially curative option. However, judicious patient selection is crucial prior to making decisions in relation to resection of BCLM.