Metformin significantly reduces colorectal cancer risk in diabetics, finds study
China: Metformin therapy significantly reduces the risk of colorectal cancer in diabetes patients, suggests a recent study in the International Journal of Colorectal Disease.
Metformin is most widely used drug in type 2 diabetes that helps diabetics to respond normally to insulin. Like most diabetic drugs, the ultimate goals of Metformin are to lower blood sugar to a normal level and maintain this level.
Many studies have been conducted on metformin and colorectal cancer risk in diabetes patients but the conclusions are contradictory. Wen-Tao Yang, Ningxia Medical University (Shuangyi Campus), Yinchuan City, China, and colleagues comprehensively collected the published literature and systematically evaluated the relationship between metformin and colorectal cancer risk in diabetes patients.
The researchers systematically searched the online databases up to March 2020. Adjusted estimates and their 95% confidence intervals (CI) were adopted to calculate summary effect estimates using either a fixed-effects or a random-effects model. A total of 17 articles were included in this study, with a total of 1,092,074 diabetes patients.
Key findings of the study include:
- Meta-analysis of observational studies showed that metformin treatment could significantly reduce the incidence of colorectal cancer in diabetic patients (adjusted RR = 0.884), and there was heterogeneity between studies.
- Subgroup analysis showed that metformin treatment was significantly associated with a significantly reduced risk of colorectal cancer in diabetics in America and Europe (adjusted RR = 0.852, adjusted RR = 0.900).
- Patients with diabetes treated with metformin had a significantly lower risk of colorectal cancer compared with patients who had never been treated with metformin or sulfonamide monotherapy (adjusted RR = 0.863, adjusted RR = 0.911).
"Metformin therapy is associated with a significantly reduced risk of colorectal disease in patients with diabetes, and it is necessary to conduct larger, more standardized clinical studies to verify this conclusion," concluded the authors.
The study, "Relationship between metformin therapy and risk of colorectal cancer in patients with diabetes mellitus: a meta-analysis," is published in the International Journal of Colorectal Disease.