SP 11.09 Incidence of Colorectal Neoplasia ≥40 Years Following Presentation with Acute Appendicitis: A Meta-Analysis
Imad-ud-din Saqib, Arzaan Shaikh, Bisam Ul Haq, Michael Powar, Heman JoshiAbstract
Introduction
Colorectal cancer is the third most common cancer worldwide and is the second leading cause of cancer-related deaths. Identifying risk factors and implementing effective screening programs are imperative in improving outcomes. We assessed the risk of colorectal cancer in adults aged ≥40 years following their first presentation with acute appendicitis due to suggestions about a possible strong link between the two.
Methods
We conducted a systematic review of the entire literature available (till May 2025) on Medline and Embase. An electronic search was conducted to identify all relevant studies. The pooled incidence was calculated using multiple methods. Heterogeneity was assessed using three complimentary tests; I² statistic, τ² (tau-squared), and Cochran’s Q test and a random-effects model utilised for all pooled estimates.
Results
Twenty eligible studies were published between 1982 and 2024 and comprised a total of 90,310 participants. The pooled incidence was estimated to be 1.0% (95% CI: 1.0% to 2.0%) with considerable statistical heterogeneity, I² = 97.2%, τ² = 1.0488 and p < 0.0001. Egger’s test for funnel plot asymmetry (z = –0.1608, p = 0.8722) showed no evidence of publication bias, indicating that smaller studies with non-significant findings were not systematically underrepresented.
Conclusion
The pooled incidence from the meta-analysis confirmed a tenfold increase compared to the reported incidence of 0.1% in the literature. This supports consideration of routine postoperative colonic evaluation in adults aged ≥40 years presenting with acute appendicitis, ideally by colonoscopy, although optimal strategies should be refined through prospective studies and cost-effectiveness analyses.