Increased incidence of gastrointestinal cancers among patients with pyogenic liver abscess: a population-based cohort study.

ABSTRACT

BACKGROUND & AIMS: The relationship between pyogenic liver abscess (PLA) and gastrointestinal (GI) cancer was first reported more than 20 years ago, yet little is known about this connection. We evaluated this association in a population-based, retrospective, cohort study. METHODS: Using Taiwan National Health Insurance claims data, we collected data on a cohort of 14,690 patients with PLA diagnosed from 2000 to 2007. A reference cohort of 58,760 persons without PLA (controls) was selected from the same database, frequency matched by age, sex, and index year. Both cohorts were followed up until the end of 2009, and incidences of GI cancer were calculated. RESULTS: The incidence of GI cancer was 4.30-fold higher among patients with PLA compared with controls (10.8 vs 2.51/1000 person-years). Site-specific analysis showed that the highest incidence of colorectal cancer was among patients with PLA and diabetes mellitus, followed by patients with PLA without diabetes and controls with diabetes (9.58, 5.76, and 1.49/10,000 person-years, respectively). The PLA cohort also had a high risk of small intestine cancer (adjusted hazard ratio [aHR], 12.7; 95% confidence interval [CI], 5.79-27.7) and biliary tract cancer (aHR, 9.56; 95% CI, 6.68-13.7). Their risk of pancreatic cancer (aHR, 2.51; 95% CI, 1.68-3.76) was also significant. However, patients with PLA did not have an increased risk of gastric cancer compared with controls. CONCLUSIONS: In a population-based study, we found that the incidence of GI cancer is increased more than 4-fold among patients with PLA compared with controls. PLA might therefore be an indicator of GI cancer. Patients with PLA had the highest incidence of colorectal cancer, followed by cancers of the biliary tract, pancreas, and small intestine.