A review of 15 case-control studies confirmed individuals with diabetes have an excess risk for pancreatic cancer.
Results showed a 30% excess risk for pancreatic cancer persisted for more than 20 years after diabetes diagnosis. That finding supports a causal role of diabetes in pancreatic cancer, according to researchers.
Cristina Bosetti, PhD, of the department of epidemiology at Istituto di Ricerche Faracologiche in Italy, and colleagues sought to assess individual-level data from case-control studies included in the Pancreatic Cancer Case-Control Consortium.
The studies included 8,305 cases and 13,987 controls. The researchers used multiple logistic regression models to estimate pooled ORs, and they made adjustments for relevant covariates.
Overall, 1,155 cases (15%) and 1,087 (8%) of controls reported a diagnosis of diabetes two or more years prior to cancer diagnosis (or interview, for controls), translating to an odds ratio of 1.9 (95% CI, 1.72-2.09).
Researchers observed consistent risk estimates when selected covariates — including BMI and smoking — were taken into account.
The risk for pancreatic cancer decreased with duration of diabetes; however, researchers observed a significant increased risk for at least 20 years after diabetes diagnosis (OR=1.3; 95% CI, 1.17-2.03).
Diabetics who used oral antidiabetics for ≥15 years demonstrated a decreased pancreatic cancer risk (OR=.31; 95% CI, 0.14-0.69). Among insulin users, researchers observed increased pancreatic cancer risk among those who reported short-term use (OR=5.6; 95% CI, 3.75-8.35 for less than 5 years) but not for those who reported longer duration of use (OR=.95; 95% CI, 0.53-1.7 for ≥15 years).
Disclosure: See the study for a full list of the researchers’ relevant financial disclosures.