Pancreatic cancer and diabetes mellitus

In a series of 6,500 patients with diabetes mellitus there were 37 cases of primary carcinoma of the pancreas which significantly exceeded the expected number for the patient years at risk in both males and females (p less than 0.01). There was no evidence that pancreatic cancer was more common in patients with long-standing diabetes. The increased incidence of pancreatic cancer in diabetic patients is probably the result of patients presenting with the symptoms of diabetes as long as four years before the cancer becomes manifest. An underlying pancreatic tumour should be suspected when an elderly diabetic proves difficult to control and loses weight despite adequate treatment.