Background: Diabetes is a risk factor for pancreatic cancer; however, its association with survival from pancreatic cancer is poorly understood. Because diabetes is a para-neoplastic manifestation of pancreatic cancer, it is vital for studies evaluating this association to establish history of diabetes before pancreatic cancer diagnosis, but such studies are lacking. Our objective was to investigate for the first time the association of diabetes with survival among pancreatic cancer patients in a cohort-based study where diabetes history was ascertained before pancreatic cancer diagnosis.

Methods: We evaluated survival by baseline (1993-2001) self-reported diabetes history (n=62) among 504 participants that developed exocrine pancreatic cancer within the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. The PLCO Screening Trial is a randomized, two-armed, controlled trial that enrolled 154,901 men and women aged 55-74 years from 10 centers in the United States between November 1993 and July 2001. Pancreatic cancer stage was abstracted at the PLCO centers in categories of localized, locally advanced, and metastatic in 2010 from previously collected pathology reports and medical records used for cancer confirmation. Information on deaths and causes of death were obtained by linking the study population to the National Death Index. Hazard ratios (HRs) and 95% confidence intervals (CIs) for mortality were estimated using Cox proportional hazards model, adjusted for age, body mass index, race, smoking, and stage.

Results: Median survival was shorter among those with diabetes (92 days) than those without diabetes (139 days, p-value=0.05). The multivariable adjusted HR for mortality comparing participants with diabetes to those without was 1.52 (95%CI 1.13-2.03, p-value <0.0001). After excluding those diagnosed with pancreatic cancer within 3 years of study enrollment, HR for mortality among those with diabetes was 1.40 (95%CI 1.05-1.99, p-value= 0.02). The association appeared to be stronger among men (HR=1.73, 95%CI 1.17-2.57, p-value= 0.006) than women (HR=1.36, 95%CI=0.84-2.22, p-value=0.216).

Conclusion: In this survival analysis using incident cases ascertained from the PLCO prospective cohort, a history of diabetes prior to pancreatic cancer diagnosis was associated with higher mortality among pancreatic cancer patients. Studies characterizing the molecular mechanisms driving this association are needed as these can provide insights into relevant pathways that could be targeted for possible therapeutic interventions.

Citation Format: Adetunji T. Toriola, Lara Dalidowitz, David Linehan, Rachael Stolzenberg-Solomon, Graham A. Colditz. Diabetes and pancreatic cancer survival: a prospective cohort study. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2169. doi:10.1158/1538-7445.AM2014-2169