S677 Long-Term Risk of Colorectal Cancer Following Cholecystectomy: A Nationwide Cohort Study

Introduction: Cholecystectomy is among the most common abdominal surgeries in the U.S. and is known to alter bile acid physiology, potentially promoting mucosal inflammation and dysplasia. While associations with colonic disorders have been hypothesized, population-level data on long-term colorectal cancer (CRC) risk after cholecystectomy remain limited. We aimed to evaluate the association between cholecystectomy and incident CRC using a large national database. Methods: We conducted a retrospective cohort study using the TriNetX research network between 2010 and 2024 to identify adult patients (≥18 years) with a history of cholecystectomy. These patients were matched 1:1 using propensity score matching with adult patients without a history of cholecystectomy, based on demographics, comorbidities, and risk factors for colorectal cancer (CRC). Patients with prior history of CRC were excluded from the analysis. The primary outcome was the risk of first diagnosis of CRC that occurred after the index event (cholecystectomy). Secondary outcomes assessed included colon cancer, rectal cancer, and subsite-specific cancers involving the right, transverse, and descending/sigmoid colon. Subgroup analyses were performed by gender and age categories. With censoring applied, Kaplan-Meier analysis with hazard ratios (HRs) and 95% CIs were used to compare time-to-event rates at daily time intervals. Results: A total of 613,396 patients with a history of cholecystectomy (mean age 48.5 ± 18.1; 68.1% female; 71.2% White) were matched to 613,396 controls. CRC incidence was significantly higher in the cholecystectomy group (1.11% vs 0.61%; aHR: 2.16, 95% CI: 2.08–2.25; P < 0.001). Risk was elevated across all age groups, with the highest aHR in patients aged 18–45 (aHR: 2.31, 95% CI: 2.08–2.56). Men had a stronger association (aHR: 2.57) compared to women (aHR: 1.93). By subsite, the right colon showed the highest CRC risk (aHR: 3.04, 95% CI: 2.81–3.28). Conclusion: Our results provide real-world evidence that cholecystectomy could be an independent risk factor for CRC development. These findings suggest that clinicians should consider incorporating CRC risk assessment into the long-term follow-up of patients post-cholecystectomy, particularly those with additional risk factors.