Pyogenic Liver Abscess as a Warning Sign for Primary Liver Cancer: A Nationwide Population-based Study

Background: There have been no large-scale population-based studies to estimate the subsequent risk ofprimary liver cancer (PLC) among patients with pyogenic liver abscess (PLA). This study aimed to providerelevant data. Materials and
Methods: The Taiwan Longitudinal Health Insurance Database for the years 2000and 2005 was used. The PLA group were adult inpatients who were newly diagnosed with PLA from 2000 to2008. The control group was randomly selected and matched with the PLA group in terms of age, sex, and datein which medical treatment was sought other than for PLA.
Results: There were 1,987 patients each in the PLAand control groups. In total, 56 had PLC, 48 (2.4%, 601.5 per 100,000 person-years) from the PLA group, and8 from the control group. After adjusting for potential covariates, the hazard ratio of PLC for the PLA groupwas 3.4 times that of the control group (95% confidence interval = 1.6-7.3, p <0.001). The PLC risk for the PLAgroup was significantly higher within the first year after PLA diagnosis (hazard ratio: 35.4) as compared withthe control group and became insignificant (hazard ratio: 2.0, 95% confidence interval = 0.8-4.9) more than oneyear after PLA diagnosis.
Conclusions: Patients with PLA have a higher rate of PLC than matched controls,especially within the first year after the diagnosis of PLA, suggesting PLA is a warning sign for PLC.