Colonoscopy Intervals and Colorectal Cancer Incidence after Adenoma Removal.

Methods

In this ongoing noninferiority trial conducted in eight European countries, we randomly assigned patients with high-risk adenomas (defined as ≥1 adenoma with a diameter of ≥10 mm, high-grade dysplasia, or villous growth or 3 to 10 adenomas of any kind) to undergo a first colonoscopy at 5 years after polyp removal or at 3 years; surveillance at 3 years is currently recommended in guidelines.

在这项正在进行的非劣效试验中，我们在八个欧洲国家随机分配了高风险腺瘤患者（定义为≥1个直径≥10毫米的腺瘤、高级别异型增生或绒毛生长，或3至10个任何类型的腺瘤）在息肉移除后5年或3年进行首次结肠镜检查；目前的指南推荐在3年后进行监测。

The 3-year group also underwent colonoscopy at 5 years.

3年组的患者也在5年时进行了结肠镜检查。

The primary end point is the cumulative incidenceof colorectal cancer at 10 years, with a prespecified noninferiority margin of 0.7 percentage points for the upper boundary of the confidence intervalfor the difference between the two groups.

主要终点是10年时结直肠癌的累积发生率，两个组之间差异的95%置信区间的上限预设非劣效边界为0.7个百分点。

Here, we report the results of an interim analysis conducted after 5.5 years of follow-up.

在这里，我们报告了在5.5年随访后进行的中期分析结果。

Inverse probability weighting was used to account for missing data owing to nonparticipation in surveillance colonoscopy at 5 years.

逆概率加权被用来考虑由于5年时未参与监测结肠镜检查而产生的缺失数据。

In this analysis, the incidenceof colorectal cancer is reported with a one-sided 99.12% confidence interval; for the final analysis at 10 years, the plan is to calculate a 95.33% confidence intervalto maintain an overall type I error of 5%.

在这次分析中，结直肠癌的发生率报告了一个单侧99.12%的置信区间；对于10年的最终分析，计划计算一个95.33%的置信区间，以保持总体I型错误为5%。

Results

A total of 10,799 patients underwent randomization: 5398 patients were assigned to the 5-year group and 5401 to the 3-year group.

共有10,799名患者进行了随机分配：5398名患者被分配到5年组，5401名患者被分配到3年组。

The 5-year cumulative incidenceof colorectal cancer was 0.77% with less-frequent surveillance and 0.82% with more-frequent surveillance (difference, -0.05 percentage points); the upper boundary of the 99.12% confidence intervalwas 0.68, which met the criterion for noninferiority.

在较少监测的情况下，结直肠癌的5年累积发生率为0.77%，而在较多监测的情况下为0.82%（差异为-0.05个百分点）；99.12%置信区间的上限为0.68，满足了非劣效性的标准。

The distribution of cancer stage at diagnosis did not appear to differ substantially between the two groups.

两组在诊断时癌症分期的分布似乎没有显著差异。

A total of 5 patients died of colorectal cancer: 3 patients (0.06%) in the 5-year group and 2 (0.04%) in the 3-year group.

共有5名患者死于结直肠癌：5年组中有3名患者（0.06%），3年组中有2名患者（0.04%）。

Conclusions

In this interim analysis of a 10-year noninferiority trial, beginning surveillance colonoscopy at 5 years after polyp removal was noninferior to beginning at 3 years with respect to the cumulative incidenceof colorectal cancer at 5 years among patients with high-risk adenomas.

在这项为期10年的非劣效性试验的中期分析中，对于高风险腺瘤患者，从息肉切除后5年开始进行监测结肠镜检查，在5年时的结直肠癌累积发生率方面，与从3年开始进行监测相比，是非劣效的。

(Funded by the Research Council of Norway and others; EPoS II ClinicalTrials.gov number, NCT02319928.).

该项目由挪威研究委员会和其他机构资助；EPoS II的ClinicalTrials.gov编号为NCT02319928。