Abstract / Summary
9Objective To characterise age-related gradients in colorectal lesion severity and prespecified high-risk endoscopic features in a lesion-confirmed screening colonoscopy cohort and to evaluate an investigator-defined red-flag composite as an exploratory marker of advanced pathology. Helicobacter pylori was assessed as a secondary exposure. Methods This retrospective cohort included 291 participants with histologically confirmed lesions in four age groups (36–45, 46–55, 56–65 and 66–72 years). Logistic regression evaluated predictors of advanced neoplasia (high-grade dysplasia [HGD] or adenocarcinoma); adenocarcinoma-only and age × H. pylori interaction analyses were exploratory because events were sparse. Results With advancing age, body mass index, H. pylori positivity, adenoma, sessile serrated lesions, HGD, adenocarcinoma and high-risk endoscopic features increased, whereas hyperplastic polyps decreased (all P < 0.05). Age (per 10 years), male sex, H. pylori positivity, lesion size ≥10 mm, proximal location and JNET 2B/3 pattern were independently associated with advanced neoplasia. Red-flag positivity (≥2 of four features) increased from 5.2% to 32.7% and enriched for adenocarcinoma, although positive predictive values were imprecise and non-monotonic. Conclusions Colorectal lesion severity and high-risk endoscopic features showed an age-related gradient. The red-flag composite is an exploratory descriptive construct, not a validated predictive score. H. pylori findings, especially interaction analyses, are hypothesis-generating and require prospective validation.