Abstract 1917: History of diabetes mellitus, cholecystectomy, and gallstone disease and risk of pancreatic cancer

Abstract

Abstract Background: Studies have shown a relationship between history of diabetes and the subsequent risk of pancreatic cancer. However, the temporal relation between diabetes and pancreatic cancer is not clearly established. Several studies also detected a positive association between cholecystectomy or abdominal surgery and pancreatic cancer risk. We examined the link between pancreatic cancer and a history of these surgeries, gallstones and diabetes in a population-based case-control study conducted in 1994-98 in Minnesota. Methods: Cases 20 y or older, were ascertained from all hospitals in the metropolitan area of the Twin Cities and a series from the Mayo Clinic. Controls were randomly selected from the general population and frequency matched to cases by age (within 5 y), sex and race. All subjects were interviewed in-person regarding history of medical conditions, the age of the diabetes onset, insulin use, and dates of surgeries. Index dates for subjects were the date of pancreatic cancer diagnosis for cases or referent date for controls. Subjects were considered as having diabetes if they reported a diagnosis of diabetes two or more years before their index dates. Unconditional logistic regression was used to estimate odds ratios of pancreatic cancer and 95% confidence intervals: OR (95% CI). Results: The mean age of cases (n=201) was 65.4 y and controls (n=657), 66.1 y. The study population was 96% Caucasian, and 62% of the cases and 56% of the controls were males. In a model adjusted for age, race, gender, education, smoking, pack-years, and alcohol, OR for pancreatic cancer was 2.2 (1.15; 4.22) for those with versus without diabetes. Associations were similar for diabetes diagnosis less than and more than 5 y before the index date: ORs were 2.47 (0.73; 8.28) and 2.1 (1.01; 4.46) respectively, compared to no diabetes. The OR was slightly higher for diabetics using insulin versus non-diabetics: 3.16 (1.27; 7.90). Pancreatic cancer was also positively associated with gallstone disease: OR=1.87 (1.11; 3.17) in a multivariate model additionally adjusted for diabetes. Compared to no cholecystectomy, ORs for pancreatic cancer were 8.53 (2.80; 25.92) for cholecystectomy < 2 y before the index date, 1.37 (0.58; 3.22) for cholecystectomy within 2-20 y, and 1.77 (0.85; 3.68) for cholecystectomy >20 y before the index date. High OR for those with cholecystectomy close to cancer diagnosis may reflect ascertainment bias or surgery for symptoms of non-diagnosed pancreatic cancer. Further adjustment for total calories, fat, fiber intake or physical activity did not markedly change the results. There was no association between pancreatic cancer and abdominal surgery that occurred two or more years before the index date. Conclusions: Our study lends support to the hypothesis that history of diabetes and cholecystectomy (or gallstone disease) are associated with pancreatic cancer risk. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1917. doi:10.1158/1538-7445.AM2011-1917