Oncologic Impact of Anastomotic Leakage Following Colorectal Cancer Surgery: A Systematic Review and Meta-Analysis

Background: Anastomotic leakage (AL) is a major complication of surgery for colorectal cancer (CRC), and is associated with increased morbidity and mortality; However, there are conflicting results on the impact of AL on long-term oncologic outcomes.

Objective: The aim of this meta-analysis was to assess the oncologic outcomes of AL following restorative surgery for CRC.

Methods: Multiple comprehensive databases, including PubMed, EMBASE, and The Cochrane Library, were searched for studies that assessed the oncologic effects of AL following surgery for CRC. The included studies evaluated local and distant recurrence, overall survival (OS), cancer-specific survival (CSS), and disease-free survival (DFS). Outcome data were pooled, and overall effect size was calculated using random effects models.

Results: Thirty-four nonrandomized studies including 78,434 patients met the inclusion criteria. The results show that AL was associated with increased local recurrence (relative risk [RR] 1.90, 95% confidence interval [CI] 1.48-2.44, I  = 78%) and reduced OS (RR 1.36, 95% CI 1.24-1.50, I  = 74%), CSS (RR 1.41, 95% CI 1.19-1.68, I  = 56%), and DFS (RR 1.40, 95% CI 1.20-1.63, I  = 86%). AL had no significant effect on distant recurrence (RR 1.20, 95% CI 0.94-1.53, I  = 61%).

Conclusions: AL after restorative surgery for CRC is associated with increased local recurrence and reduced long-term survival, including OS, CSS, and DFS.