Colonoscopic screening for colorectal cancer

Intervention 1: Intervention group: Colonoscopy. The subjects will receive screening colonoscopic examination. In case of any abnormal pathological findings, appropriate treatment will be considered for the subject. Intervention 2: Control group: No colonoscopy. Primary outcome(s): Incidence of Colorectal cancer. Timepoint: 3 years. Method of measurement: All participants in the intervention and control groups will be followed annually. Each subject will annually be contacted by a telephone call, and questions about the subject’s vital status and cancer incidence will be asked. If there is any possible evidence of developing cancer or death in each subject, the follow up team will collect supportive documents (from patient’s hospital files,...) to define the exact cause of death or type of cancer. Study Design: Randomization: Not randomized, Blinding: Not blinded, Placebo: Not used, Assignment: Parallel, Purpose: Screening.干预1：干预组：结肠镜检查（Colonoscopy）。受试者将接受结肠镜筛查。若发现任何异常病理结果，将为受试者考虑采取恰当的治疗措施。干预2：对照组：不接受结肠镜检查。主要结局指标：结直肠癌（Colorectal cancer）的发病率。随访周期：3年。测量方式：对干预组与对照组的全部受试者开展年度随访。每年将通过电话联络每位受试者，询问其生存状况与癌症发病情况。若某受试者存在疑似癌症发病或死亡的迹象，随访团队将收集佐证资料（如患者的医院档案等）以明确确切死因或癌症类型。研究设计：随机化：未实施随机分组，设盲：未采用设盲措施，安慰剂：未使用，分配方案：平行组设计，研究目的：筛查。