Association between Type 2 diabetes mellitus and gastrointestinal cancers: A meta-analysis

Abstract

Background: We analysed the association between Type 2 Diabetes Mellitus and pancreatic cancer (PaC), liver cancer (LC) and colo-rectal cancer (CRC) along with sub-group analysis on risk modification by duration of diabetes and gender-based differences. Methods: A systematic literature search was conducted using Pubmed, Google scholar, Medline and Scopus for observational studies on DM and gastro-intestinal cancers published over two decades from January 2005 till March 2023. Accordingly, 36 studies were selected (14 case-control and 22 cohort studies) estimated summary odds-ratio (OR)/risk-ratio (RR) using Mantel-Haenzel method along with 95%CI. Results: Among cohort studies, CRC showed highest risk (pooled RR=2.49, 95%CI: 2.43-2.54) followed by PaC (RR=2.06, CI:2.0-2.13) and LC (RR=1.70, CI:1.6-1.81). Among case-control studies, LC showed highest risk (OR=3.16, CI: 2.89-3.46) followed by PaC (OR=2.8, CI:2.48-3.17) and CRC (OR=1.43, CI:1.3-1.57). Risk of PaC with DM duration showed Only cohort studies of 2.31 (CI: 2.20-2.43) for DM <5yrs and RR of 1.67 (CI:1.57-1.77) for ≥ 5yrs. Higher risk in females than males, except in LC where males showed higher risk irrespective of study design. In conclusion, diabetes and gastro-intestinal cancers showed positive association which varied with duration of DM. Shorter DM duration was associated with more risk for PaC. Screening for markers of PaC in new-onset DM is advantageous. LC and CRC that develop with increasing duration of DM need frequent screening and regular follow-up for early detection and timely intervention. Males with DM are at greater risk of LC and efforts to reduce contributing risk factors, mainly alcoholism, are imperative.