Oncologic outcome and recurrence rate following anastomotic leakage after curative resection for colorectal cancer.

INTRODUCTION: Anastomotic leakage is one of the most severe early complications after colorectal surgery, and it is associated with a high reoperation rate-, and increased in short-term morbidity and mortality rates. It remains unclear whether anastomotic leakage is associated with poor oncologic outcomes. The aim of this study was to determine the impacts of anastomotic leakage on long-term oncologic outcomes, disease-free survival and overall mortality in patients who underwent curative surgery for colorectal cancer. METHODS: This single-centre, retrospective, observational cohort study included patients who underwent curative surgery for colorectal cancer between 2005 and 2015 and who had a primary anastomosis. Survival- and multivariate cox regression analyses were performed to adjust for confounding. RESULTS: A total of 1984 patients had a primary anastomosis after surgery. The overall incidence of anastomotic leakage was 7.5%; 19 patients were excluded because they were lost to follow-up. Of the remaining 1965 patients, 41 (2.1%) developed local recurrence associated with anastomotic leakage [adjusted hazard ratio (HR) = 2.25; 95% confidence interval (CI) 1.14-5.29; P = 0.03]. Distant recurrence developed in 291(14.8%) patients with no association with anastomotic leakage [adjusted HR = 1.30 (95% CI: 0.85-1.97) P = 0.23]. Anastomotic leakage was associated with increased long-term mortality [adjusted HR = 1.69 (95% CI 1.32-2.18) P < 0.01]. Five year disease-free survival was significantly decreased in patients with anastomotic leakage, (log rank test P < 0.01). CONCLUSION: Anastomotic leakage was significantly associated with increased rates of local recurrence, disease free-survival and overall mortality. Associations of anastomotic leakage with distant recurrence was not found.