Development of pancreatic cancer during observation for hepatocellular carcinoma: A retrospective cohort study

BACKGROUND/AIMS: We aimed to investigate incidence, characteristics, and possible risk factors of pancreatic cancer in patients under observation for hepatocellular carcinoma (HCC) because the association of hepatitis virus B infection and pancreatic cancer has been reported. PATIENTS AND METHODS: We performed a retrospective cohort study in the Gastroenterology Department of a University Hospital in Japan between 2004 and 2012. A total of 1848 patients who underwent treatment for HCC were included at the initiation of treatment for HCC (mean follow-up period, 33.6 months). The patients received trimonthly radiological follow-ups. Newly developed cases of pancreatic cancer during follow-up for HCC were compared with that of an age- and sex-matched theoretical cohort from national statistics. Possible predisposing factors for pancreatic cancer related to HCC were assessed. Cumulative probabilities of developing a pancreatic cancer were compared using log-rank test. RESULTS: About 13 of 1848 patients developed pancreatic cancer (mean follow-up period, 45.2 months). The risk ratio for all patients was 3.02 (log-rank test: P =0.01). Statistical analyses showed no effects of the following factors on the development of pancreatic cancer: age, sex, follow-up period, alcohol intake, laboratory data, presence of hepatitis virus, characteristics of HCC, type of treatment, number of radiological examinations, and cumulative effective dose. CONCLUSIONS: Increased incidence of pancreatic cancer was found in patients under observation for HCC in a relatively small cohort. HCC or other common underlying conditions might be a risk factor for development of pancreatic cancer.