DIABETES AND THE RISK OF PANCREATIC-CANCER

Background. Diabetes and pancreatic cancer are known to be associated, but the cause of the association and whether diabetes is a risk facto r for pancreatic cancer remain controversial. Methods. A total of 720 patients with pancreatic cancer and 720 control patients from 14 Itali an centers were enrolled in the study. All subjects were interviewed p ersonally and in detail about their clinical history. The diagnosis of diabetes was based on criteria recommended by the American Diabetes A ssociation. Results. One hundred sixty-four patients with pancreatic c ancer (22.8 percent) and 60 controls (8.3 percent) had diabetes. In th e majority of the patients with pancreatic cancer (56.1 percent), diab etes was diagnosed either concomitantly with the cancer (in 40.2 perce nt), or within two years before the diagnosis of cancer (in 15.9 perce nt). The association between the two conditions was significant (odds ratio, 3.04; 95 percent confidence interval, 2.21 to 4.17). However, w hen only patients with diabetes of three or more years' duration were considered, the association was no longer significant (odds ratio, 1.4 3; 95 percent confidence interval, 0.98 to 2.07). All the patients wit h pancreatic cancer whose diabetes had been diagnosed before the cance r had non-insulin-dependent diabetes; all but one of the control patie nts with diabetes had the noninsulin-dependent form of the disease. Co nclusions. Diabetes in patients with pancreatic cancer is frequently o f recent onset and is presumably caused by the tumor. Diabetes is not a risk factor for pancreatic cancer.