Insulin therapy contributes to the increased risk of colorectal cancer in diabetes patients: a meta-analysis

Recent epidemiological studies suggest that treatment with insulin may promote cancer growth. The present systematic review and meta-analysis of published observational studies was conducted to assess the risk of cancer during treatment with insulin.A compressive search was conducted through MEDLINE, PubMed, Web of Science, EMBASE, and Chinese Biomedical Literature databases (CBM). Pooled relative risks (RRs) and 95% confidence intervals (CIs) were calculated with a random-effects model.A total of four studies with one case-controls study and three cohort studies comparing the insulin therapy and colorectal cancer susceptibility were identified. When all four studies were analyzed, the summary RRs were 1.61 (95% CI = 1.18-1.35) in a random-effects model for individuals with insulin therapy, compared with individuals without insulin therapy, which suggests a statistically significant association between insulin use and colorectal cancer.Our findings provides the evidence that insulin therapy may contribute to the risk of colorectal cancer.The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/9339731010859509.