Clinical epidemiological analysis of the relationship between pancreatic cancer and diabetes mellitus: Data from a single institution in China

To investigate the relationship between pancreatic cancer (PC) and diabetes mellitus. All PC patients diagnosed and treated at Zhongshan hospital from January 1991 to December 2007 were retrospectively analyzed. During this period, 770 non-digestive tract, non-neoplastic and non-hormone-related patients matched for sex and age were collected as controls. The incidence of diabetes mellitus between the two groups was compared. Between the PC group and the control group, sex and age of the patients were well matched. The incidence of diabetes mellitus was 34.63% in the PC group and 8.83% in the control group (P < 0.001, RR = 5.19). In the PC group there was no correlation between age, sex, site of the cancer, tumor differentiation, lymph node metastasis, TNM staging and the incidence of diabetes mellitus. In this group with diabetes, 74.56% experienced onset within two years of cancer diagnosis. Of the control patients, 57.35% had had diabetes for under 2 years (P = 0.009, RR = 2.18). In the PC group with diabetes, 5.9% had had diabetes for more than 10 years while compared with 8.8% of the controls (P = 0.42). Whether diabetes mellitus is a result of or a risk factor for PC is still unclear. The incidence of diabetes mellitus is much higher in the PC patients. The onset of diabetes mellitus in adults might be an alerting factor that could lead to an early diagnosis of pancreatic cancer.