Screening uptake of colonoscopy versus fecal immunochemical testing in first-degree relatives of patients with non-syndromic colorectal cancer: A multicenter, open-label, parallel-group, randomized trial (ParCoFit study).

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).

Colonoscopy versus fecal immunochemical testing in colorectal-cancer screening.

BACKGROUND: Colonoscopy and fecal immunochemical testing (FIT) are accepted strategies for colorectal-cancer screening in the average-risk population. METHODS: In this randomized, controlled trial involving asymptomatic adults 50 to 69 years of age, we compared one-time colonoscopy in 26,703 subjects with FIT every 2 years in 26,599 subjects. The primary outcome was the rate of death from colorectal cancer at 10 years. This interim report describes rates of participation, diagnostic findings, and occurrence of major complications at completion of the baseline screening. Study outcomes were analyzed in both intention-to-screen and as-screened populations. RESULTS: The rate of participation was higher in the FIT group than in the colonoscopy group (34.2% vs. 24.6%, P<0.001). Colorectal cancer was found in 30 subjects (0.1%) in the colonoscopy group and 33 subjects (0.1%) in the FIT group (odds ratio, 0.99; 95% confidence interval [CI], 0.61 to 1.64; P=0.99). Advanced adenomas were detected in 514 subjects (1.9%) in the colonoscopy group and 231 subjects (0.9%) in the FIT group (odds ratio, 2.30; 95% CI, 1.97 to 2.69; P<0.001), and nonadvanced adenomas were detected in 1109 subjects (4.2%) in the colonoscopy group and 119 subjects (0.4%) in the FIT group (odds ratio, 9.80; 95% CI, 8.10 to 11.85; P<0.001). CONCLUSIONS: Subjects in the FIT group were more likely to participate in screening than were those in the colonoscopy group. On the baseline screening examination, the numbers of subjects in whom colorectal cancer was detected were similar in the two study groups, but more adenomas were identified in the colonoscopy group. (Funded by Instituto de Salud Carlos III and others; ClinicalTrials.gov number, NCT00906997.).

Risk of advanced proximal neoplasms according to distal colorectal findings: comparison of sigmoidoscopy-based strategies.

BACKGROUND: Screening for colorectal cancer with sigmoidoscopy benefits from the fact that distal findings predict the risk of advanced proximal neoplasms (APNs). This study was aimed at comparing the existing strategies of postsigmoidoscopy referral to colonoscopy in terms of accuracy and resources needed. METHODS: Asymptomatic individuals aged 50-69 years were eligible for a randomized controlled trial designed to compare colonoscopy and fecal immunochemical test. Sigmoidoscopy yield was estimated from results obtained in the colonoscopy arm according to three sets of criteria of colonoscopy referral (from those proposed in the UK Flexible Sigmoidoscopy, Screening for COlon REctum [SCORE], and Norwegian Colorectal Cancer Prevention [NORCCAP] trials). Advanced neoplasm detection rate, sensitivity, specificity, and number of individuals needed to refer for colonoscopy to detect one APN were calculated. Logistic regression analysis was performed to identify distal findings associated with APN. All statistical tests were two-sided. RESULTS: APN was found in 255 of 5059 (5.0%) individuals. Fulfillment of UK (6.2%), SCORE (12.0%), and NORCCAP (17.9%) criteria varied statistically significantly (P < .001). The NORCCAP strategy obtained the highest sensitivity for APN detection (36.9%), and the UK approach reached the highest specificity (94.6%). The number of individuals needed to refer for colonoscopy to detect one APN was 6 (95% confidence interval [CI] = 4 to 7), 8 (95% CI = 6 to 9), and 10 (95% CI = 8 to 12) when the UK, SCORE, and NORCCAP criteria were used, respectively. The logistic regression analysis identified distal adenoma ≥10 mm (odds ratio = 3.77; 95% CI = 2.52 to 5.65) as the strongest independent predictor of APN. CONCLUSIONS: Whereas the NORCCAP criteria achieved the highest sensitivity for APN detection, the UK recommendations benefited from the lowest number of individuals needed to refer for colonoscopy.