Impact of anastomotic leakage on postoperative survival of patients with colorectal cancer: A meta-analysis using propensity score matching studies

To explore the influence of anastomotic leakage (AL) on postoperative survival in patients with colorectal cancer (CRC). Although several studies have compared the postoperative survival of patients with CRC with and without AL, the background characteristics of the two groups were not aligned in most studies. We performed a comprehensive electronic search of the literature up to March 2020 to identify propensity score matching (PSM) studies that compared postoperative survival between CRC patients with and without AL. A meta-analysis was performed using random-effects models to calculate the risk ratio (RR) and 95% confidence interval (CI), and heterogeneity was analyzed using I (Akiyoshi et al., 2011) [2] statistics. Four PSM studies involving a total of 1676 patients with CRC undergoing surgery were included in this meta-analysis. Among 234 patients who had AL, 163 (69.7%) survived at 5 years after surgery, whereas among 1422 patients who did not have AL, 1156 (81.3%) survived at 5 years after surgery. Background characteristics of the two groups were adjusted with PSM in all 4 studies. The result of the meta-analysis revealed a significant difference between the two groups (RR, 1.63; 95% CI, 1.09–2.45; P = 0.02; I2 = 66%) in 5-year overall survival (OS). The results of this meta-analysis demonstrate a significantly decreased 5-year OS in patients with CRC who had AL compared with patients with CRC who did not have AL. •Background characteristics of the two groups were adjusted with propensity score matching in all 4 studies.•The result of the meta-analysis revealed a significant difference between the two groups in 5-year overall survival.•The result demonstrated a significantly decreased 5-year overall survival in patients with colorectal cancer who had anastomotic leakage.