NEW YORK (Reuters Health) – The risk of pancreatic malignancy is increased in patients with diabetes, researchers from Taiwan report in a pre-print version of a study that is scheduled to be published in the May issue of Diabetes Care.

“Although some other studies concluded that diabetes is simply a consequence of pancreatic cancer, we found that diabetic men and women without prior pancreatic cancer all experienced significantly increased risks of malignant neoplasm of the pancreas,” Dr. Chung-Yi Li from National Cheng Kung University, Tainan City, Taiwan told Reuters Health in an email.

Dr. Li and colleagues used data from Taiwan’s National Health Insurance database to investigate age- and sex-specific incidence rates and relative risks of pancreatic cancer in Taiwan’s diabetic population between 2000 and 2006.

The analysis included 615,532 diabetic patients and 614,871 age- and sex-matched controls.

“Although we could not differentiate between type 1 and type 2 diabetes in our study, type 1 diabetes constitutes only 1.8% of all diabetes in Taiwan,” the researchers note. “Therefore, the majority of diabetic patients in our study are likely to be type 2 diabetic patients.”

The overall incidence density of pancreatic malignancy was 3.34 per 10,000 patient-years for diabetic men and 2.58 per 10,000 patient-years for diabetic women, compared with 1.88 and 1.71 per 10,000 patient-years for control men and women, respectively.

The incidence density increased with age among diabetics and controls, with the highest density in those over age 65 years.

Overall, the risk of pancreatic malignancy was 66% higher in diabetic men and 43% higher in diabetic women than in their respective controls.

In the stratified analyses, the risk of pancreatic malignancy was significantly higher among diabetic men age 45 to 65 years (2.46 versus 1.28 per 10,000 patient-years, adjusted risk 1.91), diabetic men over age 65 years (3.71 versus 2.66 per 10,000 patient-years, adjusted risk 1.47), diabetic women age 45 to 65 years (1.43 versus 0.81 per 10,000 patient-years, adjusted risk 1.80), and diabetic women over age 65 years (3.23 versus 2.62 per 10,000 patient-years, adjusted risk 1.26). Differences in the under-45 years age groups did not reach statistical significance.

“The possible underlying biologic mechanism with which type 2 diabetes may cause malignant neoplasm of the pancreas has not been fully elucidated,” the investigators say.

“Our previous studies found that diabetes is not only associated with increased risk for pancreatic cancer but also with other gastrointestinal and hepatobiliary cancers,” Dr. Li said. “Further studies involving familial aggregation and metabolic factors behind these associations are warranted.”

“Screening of every diabetic patient for pancreatic neoplasm might not be cost effective, as these outcomes are rare even among diabetic patients,” Dr. Li explained. “Besides, screening of pancreatic neoplasm is difficult, because the presently available screening tests are not sensitive enough to detect small resectable neoplasms.”

Diabetes Care