OBJECTIVETo investigate the changes of blood glucose in pancreatic cancer patients associated with diabetes mellitus (DM) after radiotherapy and analyze the related factors.

METHODSClinical data of 69 cases of stage I to III pancreatic carcinoma associated with DM were retrospectively analyzed. All patients were divided into four groups according to the history of DM, and the clinical characteristics and blood glucose changes after stereotactic radiotherapy were analyzed. The correlation between blood glucose and serum tumor markers was analyzed.

RESULTSNo significant differences were found in clinical characteristics of the four groups. The history of DM <12 months accounted for 39.1% of the pancreatic cancer patients, much more higher than that of patients with a longer disease course. After radiotherapy, the blood glucose changes were not significantly different between the two groups with DM history <12 months and 12-24 months (P = 0.519), but there were significant differences between the patients with DM history <12 months and those with DM history 25-36 months and >36 months (P < 0.05 for both). After radiotherapy, CA199/CEA was reduced and blood glucose was also improved in the patients with DM history <12 months and 12-24 months, and the reduction of CA199/CEA showed a significant positive correlation with the improvement of blood glucose (r = 0.834 and r = 0.660, P < 0.01 for both), however, no significant correlation was found between the two parameters in patients with DM history 25-36 months and >36 months (r = 0.319 and r = 0.439, P > 0.05 for both).

CONCLUSIONSHyperglycemia in diabetic patients with a disease course <24 months might be a clinical manifestation secondarily developed in pancreatic cancer patients. Therefore, patients with new onset diabetes should be closely followed-up for early detection of pancreatic cancer.