The impact of anastomotic leakage on oncology after curative anterior resection for rectal cancer

BACKGROUND: Anastomotic leakage (AL) is a serious clinical complication after anterior resection for rectal cancer and will lead to an increase in postoperative mortality. However, the effect on long-term oncology outcomes remains controversial. METHODS: We searched the PubMed, Embase, and Cochrane library databases for related articles. The included studies assessed local recurrence, distant recurrence, overall survival, cancer-specific survival and disease-free survival. The systematic reviews and meta-analyses was conducted in accordance with the PRISMA guidelines. The combined RRs with 95% CI were then calculated using a fixed effects model or a randomized effect model. RESULTS: A total of 18 cohort studies included 34,487 patients who met the inclusion criteria. The meta-analysis demonstrated that AL was associated with increased local recurrence (RR 1.47, 95% CI 1.14-1.90, I = 57.8%). Anastomotic leakage decreased overall survival (RR 0.92, 95% CI 0.88-0.96, I = 58.1%), cancer-specific survival (RR 0.96, 95% CI 0.92-1.00, I = 30.4%), and disease-free survival (RR 0.85, 95% CI 0.77-0.94, I = 80.4%). Distant recurrence may had no significant effects of AL (RR 1.16, 95% CI 0.91-1.46, I = 58.4%). CONCLUSION: AL has a negative effect on local recurrence and long-term survival (including overall survival, cancer-specific survival, and disease-free survival) after anterior resection for rectal cancer, but not related to distant recurrence.