Clinicopathological and prognostic features of colorectal mucinous adenocarcinomas: a systematic review and meta-analysis

Abstract Background Many studies have explored the clinicopathological features and prognosis between colorectal mucinous adenocarcinoma (MAC) and adenocarcinoma (AC) and have given different results. This meta-analysis summarizes previous evidence and evaluates the clinicopathological and prognostic features of MAC relative to AC in colorectal cancers (CRCs). Methods The meta-analysis was conducted by searching the databases of PubMed, China National Knowledge Infrastructure (CNKI), WANFANG data, Embase, and Web of Science. Pooled odds ratios (ORs) and hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) were calculated to assess the clinicopathological and prognostic differences between MAC and AC. Results Fifty-six studies involving 803157 patients met the inclusion criteria and were included in this meta-analysis. The clinicopathological features of MAC were greatly different from AC, except for lymphatic invasion (OR = 1.07, 95% CI: 0.99–1.15, P = 0.09) and perineural invasion (OR = 0.92, 95% CI: 0.79–1.06, P = 0.09). Further investigation found that MAC predicted poor OS (HR = 1.04, 95% CI: 1.03–1.04, P