Association of Type 2 Diabetes Mellitus and Risk of Colorectal Cancers in Pyogenic Liver Abscess

Pyogenic liver abscess (PLA) has been reported as a potential clinical marker for colorectal cancer (CRC). Patients with type 2 diabetes mellitus (T2DM) are generally considered at elevated risk for infections and cancers due to impaired immune function. However, the specific relationship between T2DM and CRC among individuals with PLA remains unclear.

This retrospective cohort study was conducted using the TriNetX Global Collaborative Network. Adult patients (≥20 years) with PLA between 2010 and 2024 were identified and stratified by the presence of T2DM. Patients with amebic liver abscess were excluded. A 1:1 propensity score matching was performed to balance baseline characteristics between T2DM and non-T2DM groups, with standardized mean differences (SMD) <0.1 indicating adequate balance. The primary outcome was incident colon cancer (C18). The site-specific composite outcomes were right-sided colon and appendix cancer (C18.0-C18.4) and distal colorectal and anal cancer (C18.5-C21). The secondary outcome was all-cause mortality. Kaplan-Meier analyses with log-rank tests were used to compare cumulative incidence and survival between groups, and hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated using Cox proportional hazards models across multiple follow-up periods.

In this TriNetX-based retrospective cohort, 52,440 adults with PLA were identified, including 16,149 with T2DM. After 1:1 propensity score matching, 11,757 patients remained in each group with balanced characteristics (SMD <0.1). T2DM was not associated with an increased risk of overall colon cancer. Similar null associations were observed for the right-sided colon and appendix cancer composite and the distal colorectal and anal cancer composite., including at 3 months (HR 1.059, 95% CI 0.738-1.519), and remained non-significant at 5 years (HR 1.000, 95% CI 0.808-1.237). Findings were consistent across tumor locations. In contrast, T2DM was associated with higher all-cause mortality from 30 days (HR 1.181, 95% CI 1.051-1.326) to 5 years (HR 1.152, 95% CI 1.093-1.213).

In patients with PLA, T2DM was not associated with an increased risk of overall colon cancer or either site-specific cancer composite. However, T2DM was consistently linked to significantly higher short- and long-term mortality, highlighting its adverse prognostic impact in this population.