Survival of colorectal cancer patients with diabetes mellitus: A meta-analysis

Abstract Background Diabetes mellitus (DM) is associated with an elevated risk of various cancers, among which is colorectal cancer (CRC). Similarly, pre-existing DM may also influence prognosis among patients with CRC. We have performed a systematic review and meta-analysis to assess the association between DM and risk of death and relapse after a diagnosis of CRC. Methods PubMed, SCOPUS, Web of Science, the Cochrane Library, and EMBASE were searched from inception until July 2019, for studies reporting prognosis of patients with DM and CRC. The primary outcome of the study refers to overall mortality (OM) in patients with vs.without diabetes. Secondary endpoints were cancer-specific mortality (CSM) and progression or relapse free survival (PFS or RFS). The risk of death and relapse were reported as hazard ratios (HRs) with a 95% confidence interval (95%CI), and an HR >1 associated with the worst outcome in patients with compared to those without diabetes Results Mortality and relapse associated with DM in patients with CRC were evaluated among 5,267,980 participants (n=82 studies). Overall, concomitant diagnosis of CRC and DM were associated with an independent increased risk of OM (HR=1.21 [95%CI 1.17-1.25], P Conclusions In CRC patients with DM, diabetes reduced survival and increased the risk of relapse. Adequate control of lifestyle choices more intensive follow-ups, use of some oral antidiabetics, dietary restrictions, physical activity, and monitoring of diabetes-associated complications are measures for reducing mortality in this setting.