Impact of Postoperative Complications on Survival and Recurrence After Resection of Colorectal Liver Metastases Systematic Review and Meta-analysis

Objective: To study the effect of postoperative complications (POC) on overall survival (OS) and disease-free survival (DFS) after surgical resection of colorectal liver metastases (CRLM). Summary Background Data: Morbidity rates after liver resection can reach 45%. The negative impact of POC on oncologic outcomes has been reported in various types of cancer, especially colorectal. However, data on the consequences of POC after CRLM resection on long-term survival are scarce. Methods: Eligible studies examining the association between POC after CRLM resection and OS/DFS were sought using the PubMed and Web of Science databases. A random-effects model was used to calculate pooled effect estimate for OS and DFS hazard ratios (HR), estimating between-study variance with restricted maximum likelihood estimator with Hartung-Knapp adjustment. Subgroup analysis was used to control the effect of POC on OS and DFS for: 1) Method used to define postoperative complications, 2) Exclusion of early postoperative death from survival analysis, 3) Method of data extraction used, and 4) Tumor and treatment characteristics. Results: Forty-one studies were deemed eligible, including 12,817 patients. POC patients had a significant risk of reduced OS compared with no POC group (HR 1.43 [95% CI: 1.3, 1.57], P < 0.0001). POC had also a negative impact on DFS. The HR for reduced DFS was 1.38 [95% CI 1.27, 1.49], P < 0.0001. The negative impact of POC on survival and recurrence was confirmed in subgroup analysis. Conclusions: Our findings evidence the negative impact of POC on survival and recurrence after CRLM resection.