S328 Aspirin in Diverticulitis: A Hidden Risk? Uncovering Cancer and Mortality Dangers to Shape Future Guidelines

Introduction: Aspirin is commonly used for cardiovascular prevention, yet its impact on patients with diverticulitis remains under explored. Given emerging concerns about aspirin's risks in certain populations and the evolving guidelines around its use, this study aimed to evaluate whether aspirin use in patients with diverticulitis is associated with increased risk of colorectal cancer, colonic adenoma, all-cause mortality, and need for colectomy. Methods: We conducted a retrospective analysis of deidentified, aggregate patient data from the TriNetX research network. The cohort comprised patients ≥18 years old with a diagnosis of diverticulitis. Within this cohort, patients who were on aspirin with a diagnosis of diverticulitis were identified. Primary outcomes were the incidence of colorectal cancer, colonic adenoma, all-cause mortality, and the need for colectomy. Variables including age, sex, race, comorbidities (such as diabetes, obesity, and chronic kidney disease), and lifestyle factors (such as tobacco use and alcohol dependence) known to confound the association between aspirin use and the composite outcomes underwent 1:1 propensity matching. Cox proportional hazards regression analysis was also utilized to analyze the matched cohorts. Hazard ratios and 95% confidence intervals (95% CI) were reported in this analysis. Results: The matched cohort analysis revealed that aspirin use was associated with a significantly higher risk of colorectal cancer (hazard ratio [HR] 1.313, 95% confidence interval [CI] 1.272-1.356, P < 0.001), colonic adenoma (HR 1.336, 95% CI 1.292-1.382, P < 0.001), and all-cause mortality (HR 1.914, 95% CI 1.874-1.955, P < 0.001). However, a lower risk of requiring colectomy was observed among aspirin users (HR 0.931, 95% CI 0.876-0.989, P = 0.021). Conclusion: Our findings suggest that aspirin use in patients with diverticulitis is associated with significantly elevated risks of colorectal neoplasia and mortality, despite a modest reduction in colectomy rates. These results underscore the need to reconsider aspirin’s routine use in patients at risk for or diagnosed with diverticulitis. Given shifting guidelines that discourage aspirin for primary prevention in older adults, clinicians should carefully weigh the risks and benefits in this population. Further prospective studies are warranted to guide evidence-based recommendations.