Efficacy of Colonoscopy, Colon Capsule and Fecal Immunological Test for Colorectal Cancer Screening

Fecal immunological test (FIT) is the reference screening method in average risk patient. FIT is proposed every 2 years to all asymptomatic subjects with average risk aged from 50 to 74 years in France. Optical colonoscopy (OC) is the gold standard examination for patients at increased risk of colorectal cancer, like those with a first degree relative with colorectal cancer (relative risk between 2 and 4 times that of the general population). Colonoscopy should be performed in this high risk group before 50 years or 5 to 10 years before the earliest case of colorectal cancer. Optical colonoscopy has important limitations: complications (perforation, bleeding), need to use general anesthesia (in France 95% of colonoscopy are performed under general anesthesia), and low acceptability for screening even in high risk persons (40% in the best cases). In this high risk population, there is a potentially important place for alternative methods. FIT could be one of them, with already a significant amount of data suggesting its interest. No data are available in high risk French patients. Colon capsule endoscopy (CC) is a more recent technique with sparse data in this high risk group, and no prospective comparison with optical colonoscopy in this indication. Capsule endoscopy has the advantage of high feasibility, very low risk, probably (but to be demonstrated) increased acceptability, and represents the closest examination as compared to colonoscopy. This justifies a prospective study comparing in a randomized methodology these 3 modalities for the identification of advanced neoplastic lesions of the colon in well characterized group of subjects at high risk of colorectal cancer. The investigators propose a prospective, randomized protocol of non-inferiority in order to compare the two new strategies to the reference strategy for the detection of advanced colorectal neoplasia (colon or rectal cancers, large adenoma \> 1 cm or high grade dysplasia ; 1st arm: OC first; 2nd arm: CC first, OC at 3 years for those patients with negative initial CC; 3rd arm: annual FIT for 2 years (t0, t = 1 year, t = 2 years), colonoscopy at 3 years for those patients with negative FIT during the study). The new strategies will be considered non-inferior to the reference strategy if the study allows to conclude that the absolute reduction of the proportion of detected patients is not greater than 3% in comparison to the reference strategy.