Diagnostic Yield and Histopathological Features of Colorectal Lesions Detected Through a Regional Screening Program...

Background/Objectives: Colorectal cancer (CRC) represents a major cause of cancer-related morbidity and mortality worldwide, particularly in regions with delayed or incomplete implementation of population-based screening programs. Evidence describing the burden and characteristics of colorectal lesions detected through organized screening initiatives in Eastern Europe is still limited. Methods: This retrospective study analyzed data from a regional CRC screening program conducted between November 2020 and December 2023 in South-West Oltenia, Romania. A total of 1550 individuals aged 50-74 years underwent colonoscopic evaluation following fecal immunochemical testing or direct referral based on risk assessment. Lesion characteristics, including size, anatomical distribution, histopathological subtype, dysplasia grade, tumor differentiation, and resection margin status, were systematically analyzed. Associations between demographic variables and lesion characteristics were evaluated using appropriate statistical methods. Results: At least one colorectal lesion was identified in 63.7% of colonoscopies, with a total of 5001 lesions detected. Most lesions measured <10 mm. Serrated lesions (51.4%) and conventional adenomas (42.2%) predominated, while invasive adenocarcinoma was identified in 6.2% of cases. Increasing lesion size was significantly associated with higher-grade dysplasia, incomplete resection margins and advanced histopathological features (p < 0.05). Age showed significant associations with histopathological subtype and resection margin status, whereas male sex was linked to higher-grade dysplasia and adenocarcinoma (p < 0.05). Conclusions: This study revealed a relatively high prevalence of precancerous and malignant colorectal lesions in a previously unscreened population. The strong associations between lesion size, dysplasia severity, and resection completeness underscore the importance of early detection and quality-controlled colonoscopy. These findings support the expansion of organized CRC screening programs and the integration of quality indicators to enhance diagnostic accuracy.