Chronic pancreatitis and cancer risk in a matched cohort study using national claims data in South Korea

This study aimed to examine the association between chronic pancreatitis (CP) and cancer incidence and mortality among the Korean population. Based on a cancer-free cohort of 8,317,616 individuals between 2002 and 2010, a matched cohort study was conducted, including 10,899 patients with CP, matched for sex and age with 32,697 individuals without CP. The case and control groups were followed up until the date of onset of cancer or death or the end of follow-up date (December 31, 2018). Cox proportional hazards regression was performed to assess the risk of cancer incidence and mortality. Compared to the control group, patients with CP had a higher risk of all cancers with a hazard ratio (HR) of 1.2 [95% confidence interval (CI) 1.1-1.3]. CP was associated with an increased risk of esophageal cancer (HR 3.9, 95% CI 1.8-8.5) and pancreatic cancer (HR 3.9, 95% CI 2.7-5.5) and a decreased risk of colorectal cancer (HR 0.7, 95% CI 0.5-0.9). Regarding cancer mortality, patients with CP had a 1.2-fold risk of all cancer mortality (95% CI 1.1-1.4), compared with the control group. Patients with CP had a higher risk of death from esophageal cancer (HR 3.5, 95% CI 1.5-8.0) and pancreatic cancer (HR 3.3, 95% CI 2.3-4.7) but had a lower risk of death due to stomach cancer (HR 0.4, 95% CI 0.2-0.8). Patients with CP had a higher risk for both incidence and mortality of all cancer types, especially pancreatic and esophageal cancers, compared with the sex- and age-matched control group.