BACKGROUND Colonoscopy screening is underused by first-degree relatives (FDRs) of patients with non-syndromic colorectal cancer (CRC) with screening completion rates below 50%. Studies conducted in FDR referred for screening suggest that fecal immunochemical testing (FIT) was not inferior to colonoscopy in terms of diagnostic yield and tumor staging, but screening uptake of FIT has not yet been tested in this population. In this study, we investigated whether the uptake of FIT screening is superior to the uptake of colonoscopy screening in the familial-risk population, with an equivalent effect on CRC detection. METHODS AND FINDINGS This open-label, parallel-group, randomized trial was conducted in 12 Spanish centers between February 2016 and December 2021. Eligible individuals included asymptomatic FDR of index cases <60 years, siblings or ≥2 FDR with CRC. The primary outcome was to compare screening uptake between colonoscopy and FIT. The secondary outcome was to determine the efficacy of each strategy to detect advanced colorectal neoplasia (adenoma or serrated polyps ≥10 mm, polyps with tubulovillous architecture, high-grade dysplasia, and/or CRC). Screening-naïve FDR were randomized (1:1) to one-time colonoscopy versus annual FIT during 3 consecutive years followed by a work-up colonoscopy in the case of a positive test. Randomization was performed before signing the informed consent using computer-generated allocation algorithm based on stratified block randomization. Multivariable regression analysis was performed by intention-to-screen. On December 31, 2019, when 81% of the estimated sample size was reached, the trial was terminated prematurely after an interim analysis for futility. Study outcomes were further analyzed through 2-year follow-up. The main limitation of this study was the impossibility of collecting information on eligible individuals who declined to participate. A total of 1,790 FDR of 460 index cases were evaluated for inclusion, of whom 870 were assigned to undergo one-time colonoscopy (n = 431) or FIT (n = 439). Of them, 383 (44.0%) attended the appointment and signed the informed consent: 147/431 (34.1%) FDR received colonoscopy-based screening and 158/439 (35.9%) underwent FIT-based screening (odds ratio [OR] 1.08; 95% confidence intervals [CI] [0.82, 1.44], p = 0.564). The detection rate of advanced colorectal neoplasia was significantly higher in the colonoscopy group than in the FIT group (OR 3.64, 95% CI [1.55, 8.53], p = 0.003). Study outcomes did not change throughout follow-up. CONCLUSIONS In this study, compared to colonoscopy, FIT screening did not improve screening uptake by individuals at high risk of CRC, resulting in less detection of advanced colorectal neoplasia. Further studies are needed to assess how screening uptake could be improved in this high-risk group, including by inclusion in population-based screening programs. TRIAL REGISTRATION This trial was registered with ClinicalTrials.gov (NCT02567045).

中文翻译：

---

在非综合征性结直肠癌患者的一级亲属中筛查结肠镜检查与粪便免疫化学检测的情况：一项多中心、开放标签、平行组、随机试验（ParCoFit 研究）。

背景 非综合征性结直肠癌 (CRC) 患者的一级亲属 (FDR) 未充分利用结肠镜筛查，筛查完成率低于 50%。FDR 进行的筛查转介研究表明，粪便免疫化学检测 (FIT) 在诊断率和肿瘤分期方面并不逊色于结肠镜检查，但尚未在该人群中测试 FIT 的筛查吸收情况。在这项研究中，我们调查了在家族风险人群中 FIT 筛查的接受率是否优于结肠镜检查筛查的接受率，并且对 CRC 检测的效果相当。方法和结果 这项开放标签、平行组、随机试验于 2016 年 2 月至 2021 年 12 月在西班牙 12 个中心进行。符合条件的个体包括 <60 岁的无症状 FDR 病例、兄弟姐妹或≥2 个 FDR 患有 CRC 的病例。主要结果是比较结肠镜检查和 FIT 的筛查率。次要结果是确定每种策略检测晚期结直肠肿瘤（腺瘤或锯齿状息肉≥10毫米、具有管状绒毛状结构的息肉、高度不典型增生和/或结直肠癌）的有效性。首次筛查过的 FDR 被随机 (1:1) 接受一次性结肠镜检查与连续 3 年每年一次的 FIT，然后在检测呈阳性的情况下进行结肠镜检查。在签署知情同意书之前，使用基于分层分组随机化的计算机生成的分配算法进行随机化。通过意向筛选进行多变量回归分析。2019 年 12 月 31 日，当达到估计样本量的 81% 时，试验在中期分析无效后提前终止。通过两年的随访进一步分析研究结果。这项研究的主要局限性是无法收集拒绝参与的合格个人的信息。对 460 例索引病例中的总共 1,790 名 FDR 进行了纳入评估，其中 870 例被分配接受一次性结肠镜检查 (n = 431) 或 FIT (n = 439)。其中，383 名 (44.0%) 参加了预约并签署了知情同意书：147/431 (34.1%) 名 FDR 接受了基于结肠镜检查的筛查，158/439 (35.9%) 名接受了基于 FIT 的筛查（比值比 [OR] 1.08 ；95% 置信区间 [CI] [0.82, 1.44]，p = 0.564）。结肠镜检查组晚期结直肠肿瘤的检出率显着高于FIT组（OR 3.64，95% CI [1.55，8.53]，p = 0.003）。研究结果在整个随访过程中没有变化。结论 在这项研究中，与结肠镜检查相比，FIT 筛查并没有提高 CRC 高风险个体的筛查率，导致晚期结直肠肿瘤的检出率较低。需要进一步的研究来评估如何提高这一高危人群的筛查率，包括纳入基于人群的筛查计划。试验注册 该试验已在 ClinicalTrials 注册。