Hyderabad: Colorectal cancer screening is recommended for people aged 50–75 years, but the optimal screening test and strategy are not established. The study aimed to compare single CT colonography versus three faecal immunochemical test (FIT) rounds for population-based screening of colorectal cancer. The randomised controlled trial was done in Florence, Italy.
Exclusion criteria included previous colorectal cancer, advanced adenoma, or inflammatory bowel disease, colonoscopy within the last 5 years or severe medical conditions. Participants who had a colonic mass or at least one polyp of 6 mm or more in diameter in the CT colonography group and those who had at least 20 μg haemoglobin per g faeces in the FIT group were referred for work-up optical colonoscopy. The primary outcome was the detection rate for advanced neoplasia.
From Dec 12, 2012, to March 5, 2018, 14 981 adults were randomised and invited to screening interventions. 5242 individuals (2809 [53·6%] women and 2433 [46·4%] men) were assigned to the CT colonography group and 9739 individuals (5208 [53·5%] women and 4531 [46·5%] men) were assigned to the FIT group. Participation in the screening intervention was lower in the CT colonography group than it was for the FIT group.
The detection rate for advanced neoplasia of CT colonography was significantly lower than the detection rate after three FIT rounds in the modified intention-to-screen analysis, but the detection rate was significantly higher in the CT colonography group than in the FIT group in the per-protocol analysis. Referral rate to work-up optical colonoscopy was significantly lower for the CT colonography group than for the FIT group after three FIT rounds in the modified intention-to-screen analysis, whereas no significant difference was observed in the per-protocol analysis.
No major complications were observed in the CT colonography group after screening and work-up optical colonoscopy, whereas three cases of bleeding were reported in the FIT group after work-up optical colonoscopy. Greater participation makes FIT more efficient than single CT colonography for the detection of advanced neoplasia in population screening for colorectal cancer. Nonetheless, a higher detection rate in participants and fewer work-up colonoscopies are possible advantages of CT colonography as a screening tool, which might deserve consideration in future trials.
