Precision Screening

This is a multicenter, observational study designed to develop and validate a diagnostic model for colorectal cancer and advanced colorectal neoplasia among adults undergoing routine-care colonoscopy in the Chinese population. The study will enroll adults aged 18 to 80 years who have already been scheduled or planned to undergo colonoscopy according to routine clinical care, physical examination, or screening pathways at participating medical institutions. The study will not invite, organize, require, or otherwise arrange colonoscopy for any participant. Colonoscopy, bowel preparation, anesthesia assessment, biopsy, pathology examination, and subsequent clinical management will be performed solely according to the existing clinical pathway of each participating institution. After informed consent, participants will be invited to complete a standardized electronic questionnaire before their scheduled colonoscopy. The questionnaire will collect self-reported information on demographic characteristics, lifestyle factors, environmental exposures, personal medical history, family history of colorectal cancer, prior colonoscopy history, and gastrointestinal symptoms. The study team will also abstract colonoscopy and pathology results from medical records. No additional biological specimens will be collected for research purposes. The primary clinical outcome is prevalent colorectal advanced neoplasia, defined as colorectal cancer, advanced colorectal adenoma, or advanced colorectal serrated lesion identified through colonoscopy and associated pathology. Statistical and machine-learning approaches will be used to develop and validate diagnostic models. Model performance will be evaluated by discrimination, calibration, and clinical net benefit in internal validation and multicenter external validation.

To evaluate the feasibility, applicability, effectiveness, and health-economic value of the risk-based sequential screening modality for esophageal and gastric cancers, the investigators aim to initiate a community-based randomized controlled trial in Xun County, Henan Province, which is a high-risk region of upper gastrointestinal cancer (UGIC) in northern China. A total of 258 target villages from all the 11 communities (townships and streets) in Xun County will be randomly selected and assigned to the sequential screening group and the universal screening group at a ratio of 2:1 and the total sample size will be 21,000. In the sequential screening group, participants in the top 50% risk level (i.e., stratified as the high-risk subgroup) will be offered a standard upper gastrointestinal endoscopic screening. In contrast, all participants in the universal screening group will receive the endoscopic examination. The surveillance strategy for participants with screening-detected premalignant lesions in the sequential screening group will be tailored based on individualized risk assessment using endoscopic characteristics, pathological diagnosis, and biomarkers. Surveillance for participants in the universal screening group will adhere to current guidelines for UGIC screening and clinical treatment. Detection rates of upper gastrointestinal malignant lesions, early-stage malignant lesions and premalignant lesions, and health-economic indicators such as the unit cost per detected malignant lesions will be compared between the two groups.