Association of elevated risk of pancreatic cancer in diabetic patients: A systematic review and meta-analysis

Pancreatic cancer has a five-year overall survival rate <5%, a situation that has not improved since for 40 years. Diabetes mellitus including type 2 diabetes mellitus (T2D) is a suspected risk factor for the development of pancreatic cancer and nearly 45% of the pancreatic cancer cases are likely to present as new onset diabetes cases; however, the nature of association between T2D and pancreatic cancer is still controversial. In this meta-analysis, we examined the association specifically of T2D with pancreatic cancer and the influence of insulin therapy. PubMed, EMBASE, Scholar, Web of Science and Scopus databases were searched to identify clinical and patient oriented studies that examined the incidence of diabetes in pancreatic cancer patients and vice versa, over the last 10 years. All the authors independently screened the articles, and a collective decision was reached about the studies included in the meta-analysis. Parameters analyzed included, the Incidence of diabetes in pancreatic cancer patients; duration history of T2D in pancreatic cancer patients; influence of insulin therapy in T2D patients on pancreatic cancer incidence. Eleven studies with a total of 14,399 patients, of whom 4,080 were T2D-positive and 9,721 were non-diabetic were included in this meta-analysis. T2D duration history was significantly related to pancreatic cancer incidence and insulin therapy effects. In conclusion, recent-onset T2D is probably a manifestation of pancreatic cancer whereas long-term T2D is likely a risk factor for this cancer. Insulin therapy appears to decrease the incidence of pancreatic cancer.