S561 Aspirin's Potential in Colorectal Cancer Prevention Amidst Low Screening Rates: A Case-Control Study in a Southeast Asian Population

Introduction: Colorectal cancer (CRC) poses a substantial global health challenge. Among potential preventative strategies, long-term, low-dose daily aspirin is recognized for its chemopreventive effects against CRC, primarily through its anti-inflammatory and anti-platelet actions. To address this critical knowledge gap, we conducted a case-control study to evaluate the association between aspirin use and CRC risk within a Southeast Asian population, specifically accounting for varied colonoscopy screening histories. Methods: A case-control study was conducted among the Southeast Asian population considering 70 participants with biopsy confirmed diagnosis of CRC as case group and 70 participants with no diagnosis of CRC and age matched randomised selection as control group. Data related to sociodemographic factors, daily single dose of aspirin for at least 6 months prior to diagnosis or interview, and regular colonoscopy screening as per the guidelines were collected using a structured interview and records. Later, chi-square test and odds ratio was used to determine the association of incidence of CRC with sociodemographic factors and practicing preventive measures like usage of daily aspirin and regular colonoscopy screening. Results: A total of 140 participants were included in the study. A total of 70 patients with diagnosis of CRC were taken as case group, of which majority of them were men (64.3%), falling in the 61-90 years age group (42.9%), with education upto Mid School (28.6%), residing in urban areas (40%), and following a non-veg diet (58.6%). Statistical analysis revealed that the incidence of CRC was significantly associated with male gender (P < 0.05), age group of 61-70 years (P < 0.05), and non-veg diet (P < 0.05). Analysis revealed that individuals who underwent colonoscopy screening and reported regular aspirin use demonstrated a significantly lower risk of CRC (odds ratio [OR] = 0.27, 95% CI: 0.11-0.71, P = 0.007) compared to the reference group (neither colonoscopy nor aspirin use). The group with no history of colonoscopy and no aspirin use had the highest prevalence of CRC. Conclusion: This study highlights the potential of the combined protective role of colonoscopy screening and aspirin use in the prevention of CRC, particularly in a Southeast Asian population with low baseline screening rates. These findings underscore the importance of targeted screening programs and chemoprevention strategies to mitigate CRC burden in resource-limited settings.