Significantly increased risk of cancer in patients with diabetes mellitus: A systematic review and meta-analysis

Objective: To conduct a review and meta-analysis of the effect of diabetes mellitus on the incidence of and mortality attributable to cancer at any anatomic site.Methods: We performed a search of MEDLINE and the Cochrane Library for pertinent articles published from the origin of these databases to July 5, 2010, and included them in a qualitative review and meta-analysis of the risk of all-cancer incidence and mortality in patients with diabetes.Results: Among patients with diabetes (n = 257,222) in 12 cohort studies, the cancer incidence was about 7%. The cancer mortality was approximately 3% among patients with diabetes (n = 152,091) in 19 cohort studies. The pooled adjusted risk ratio (RR) of all-cancer incidence was significantly elevated-RR, 1.10 (95% confidence interval [CI], 1.04 to 1.17) overall; RR, 1.14 (CI, 1.06 to 1.23) for men; and RR, 1.18 (CI, 1.08 to 1.28) for women. Diabetes was also associated with an increased RR of mortality across all cancer types-RR, 1.16 (CI, 1.03 to 1.30) overall; RR, 1.10 (CI, 0.98 to 1.23) for men; and RR, 1.24 (CI, 1.11 to 1.40) for women.Conclusion: Cancer prevention and early detection by appropriate screening methods in patients with diabetes should be important components of clinical management and investigation, inasmuch as the exponentially increasing prevalence of diabetes will translate into substantial clinical and public health consequences on a global scale.