Histopathological Spectrum and Yield of Advanced Neoplasia in Opportunistic Colonoscopy Without Organised Screening: A Single-Centre Cross-Sectional Study from Western Romania

Background/Objectives: Organised colorectal cancer screening is still being introduced in Romania, and the yield of opportunistic colonoscopy outside it is poorly documented. Our primary aim was to describe the histopathological spectrum and the yield of advanced neoplasia in an opportunistic colonoscopy service; a secondary, exploratory aim was to describe self-reported lifestyle items in a questionnaire subgroup. Methods: This study represents a retrospective cross-sectional analysis of consecutive colonoscopies (June 2023–June 2024) at a county hospital outside organised screening, restricted to patients from whom material reached histopathology; the comparison group therefore comprises patients whose sampled lesions were benign, not patients without neoplasia. Advanced neoplasia was defined histologically as adenocarcinoma or adenoma with high-grade dysplasia, without the 10 mm size criterion. A convenience subgroup self-completed a locally developed, unvalidated questionnaire before the procedure; its items were tested against advanced neoplasia and adenocarcinoma with false discovery rate correction. Results: Among 274 patients, 45 (16.4%) had adenocarcinoma, 139 (50.7%) adenoma and 72 (26.3%) advanced neoplasia; per examination (n = 978), detection was 4.6% for adenocarcinoma and 7.4% for advanced neoplasia. Forty-four of 45 carcinomas were graded as moderately differentiated, and no serrated lesion was separately reported. Age was associated with advanced neoplasia (OR 1.34 per decade, 95% CI 1.01–1.79). Questionnaire data were available for only 79 patients (28.8%), among whom adenocarcinoma was more frequent than among non-respondents (26.6% vs. 12.3%). In this subgroup, obesity was inversely (OR 0.07, 95% CI 0.02–0.28) and reported weight loss positively (OR 6.77, 2.26–20.30) associated with advanced neoplasia, and two coffee items were inversely associated; processed meat, dairy, aspirin and supplement use were not associated after correction. Conclusions: Opportunistic colonoscopy at this centre recovered a high proportion of carcinoma, consistent with symptom-driven presentation, and the reporting of serrated lesions and tumour grade requires standardisation. The questionnaire findings rest on a small, selected subgroup and are hypothesis-generating only. The inverse obesity association is most plausibly explained by selection of the comparison group and of respondents, and none of the associations identifies a risk factor.