Incidence of Colorectal Cancer in Patients Diagnosed with Pyogenic Liver Abscess

Abstract

Importance: Colorectal cancer (CRC) can compromise the mucosal barrier and subsequently allow a route for bacterial invasion into the portal system or systemic circulation. Despite preliminary data suggesting that patients who experienced pyogenic liver abscess (PLA) have higher CRC incidence rates, data from outside the Southeast Asian population are sparse. Objective: To investigate whether there is an association between PLA and the subsequent incidence of diagnosed CRC using the Veterans Health Administration (VHA) cohort. Design, Setting, and Participants: A patient-level matched retrospective cohort study was conducted at 127 VHA hospitals across the US from January 1, 2003, to December 31, 2020. Patients were followed up to 10 years from PLA diagnosis. Data analysis was performed from April 14, 2002, to October 31, 2023. All patients who were admitted to VHA hospitals with a diagnosis of PLA were included. For each patient with PLA, up to 3 controls without diagnosis of PLA, matching age, sex, and health care facility, were selected. Exposure: Pyogenic liver abscess. Main Outcomes and Measures: The primary outcome was CRC diagnosis during the follow-up period. A multivariable Fine-Gray subdistribution regression model with time-dependent coefficient was used to estimate the time-varying hazard ratio (HR) of CRC incidence while accounting for mortality as a competing event. Results: A total of 8286 patients with PLA (male, 96.5%; mean [SD] age, 65.8 [11.9] years) and 23201 patient-level matched controls (male, 96.3%; mean age, 65.3 [11.7] years) were included. A diagnosis of CRC was found in a significantly higher proportion of patients with PLA compared with controls (1.9% [159 of 8286] vs 0.8% [196 of 23201]; P