Objective Postpolypectomy colonoscopy surveillance aims to prevent colorectal cancer (CRC). The 2002 UK surveillance guidelines define low-risk, intermediate-risk and high-risk groups, recommending different strategies for each. Evidence supporting the guidelines is limited. We examined CRC incidence and effects of surveillance on incidence among each risk group. Design Retrospective study of 33 011 patients who underwent colonoscopy with adenoma removal at 17 UK hospitals, mostly (87%) from 2000 to 2010. Patients were followed up through 2016. Cox regression with time-varying covariates was used to estimate effects of surveillance on CRC incidence adjusted for patient, procedural and polyp characteristics. Standardised incidence ratios (SIRs) compared incidence with that in the general population. Results After exclusions, 28 972 patients were available for analysis; 14 401 (50%) were classed as low-risk, 11 852 (41%) as intermediate-risk and 2719 (9%) as high-risk. Median follow-up was 9.3 years. In the low-risk, intermediate-risk and high-risk groups, CRC incidence per 100 000 person-years was 140 (95% CI 122 to 162), 221 (195 to 251) and 366 (295 to 453), respectively. CRC incidence was 40%–50% lower with a single surveillance visit than with none: hazard ratios (HRs) were 0.56 (95% CI 0.39 to 0.80), 0.59 (0.43 to 0.81) and 0.49 (0.29 to 0.82) in the low-risk, intermediate-risk and high-risk groups, respectively. Compared with the general population, CRC incidence without surveillance was similar among low-risk (SIR 0.86, 95% CI 0.73 to 1.02) and intermediate-risk (1.16, 0.97 to 1.37) patients, but higher among high-risk patients (1.91, 1.39 to 2.56). Conclusion Postpolypectomy surveillance reduces CRC risk. However, even without surveillance, CRC risk in some low-risk and intermediate-risk patients is no higher than in the general population. These patients could be managed by screening rather than surveillance.

中文翻译：

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腺瘤切除后的长期结直肠癌发病率和监测对发病率的影响：一项多中心、回顾性、队列研究

目的 息肉切除术后结肠镜检查旨在预防结直肠癌 (CRC)。2002 年英国监测指南定义了低风险、中风险和高风险人群，并为每个人群推荐了不同的策略。支持指南的证据有限。我们检查了每个风险组的 CRC 发病率和监测对发病率的影响。设计 在英国 17 家医院接受结肠镜检查和腺瘤切除术的 33 011 名患者的回顾性研究，大部分 (87%) 从 2000 年到 2010 年。患者随访至 2016 年。使用时变协变量的 Cox 回归来估计监测对CRC 发生率根据患者、手术和息肉特征进行了调整。标准化发病率 (SIR) 将发病率与一般人群进行了比较。结果排除后，28 972 名患者可供分析；14 401 (50%) 被归类为低风险，11 852 (41%) 被归类为中风险，2719 (9%) 被归类为高风险。中位随访时间为 9.3 年。在低危、中危和高危组中，每 10 万人年的 CRC 发生率分别为 140（95% CI 122 至 162）、221（195 至 251）和 366（295 至 453）。单次监测随访的 CRC 发生率比无随访低 40%–50%：风险比 (HR) 为 0.56（95% CI 0.39 至 0.80）、0.59（0.43 至 0.81）和 0.49（0.29 至 0.82） - 风险，中风险和高风险组，分别。与普通人群相比，低风险（SIR 0.86，95% CI 0.73 至 1.02）和中风险（1.16，0.97 至 1.37）患者的未监测CRC 发生率相似，但高风险患者（1.91， 1.39 到 2.56）。结论 息肉切除术后监测可降低 CRC 风险。然而，即使没有监测，一些低危和中危患者的 CRC 风险也不高于一般人群。这些患者可以通过筛查而不是监测来管理。