Comparing CT colonography and flexible sigmoidoscopy: A randomised trial within a population-based screening programme

Daniele Regge, Gabriella Iussich, Nereo Segnan, Loredana Correale, Cesare Hassan, Arrigo Arrigoni, Roberto Asnaghi, P. Bestagini, Gianmarco Bulighin, M. C. Cassinis, Andrea Ederle, Andrea Ferraris, Giovanni Galatola, Teresa Gallo, Giovanni Gandini, L. Garretti, Maria Cristina Martina, Daniela Molinar, Stefania Montemezzi, Lia MorraMassimiliano Motton, P. Occhipinti, Lucia Pinali, Gian Alberto Soardi, Carlo Senore

Research output: Contribution to journalArticlepeer-review


Importance and aims The role of CT colonography (CTC) as a colorectal cancer (CRC) screening test is uncertain. The aim of our trial was to compare participation and detection rate (DR) with sigmoidoscopy (flexible sigmoidoscopy (FS)) and CTC in a screening setting. Design setting and participants We conducted two randomised clinical trials (RCTs). (1) Participation RCT: individuals, aged 58 years, living in Turin (Italy), were randomly assigned to be invited to FS or CTC screening; (2) detection RCT: residents in northern Italy, aged 58-60, giving their consent to recruitment, were randomly allocated to CTC or FS. Polyps =6 mm at CTC, or 'high-risk' distal lesions at FS, were referred for colonoscopy (TC). Main outcome measures Participation rate ( proportion of invitees examined); DR of advanced adenomas or CRC (advanced neoplasia (AN)). Results Participation was 30.4% (298/980) for CTC and 27.4% (267/976) for FS (relative risk (RR) 1.1; 95% CI 0.98 to 1.29). Among men, participation was higher with CTC than with FS (34.1% vs 26.5%, p=0.011). In the detection RCT, 2673 subjects had FS and 2595 had CTC: the AN DR was 4.8% (127/2673, including 9 CRCs) with FS and 5.1% (133/2595, including 10 CRCs) with CTC (RR 1.08; 95% CI 0.85 to 1.37). Distal AN DR was 3.9% (109/2673) with FS and 2.9% (76/2595) with CTC (RR 0.72; 95% CI 0.54 to 0.96); proximal AN DR was 1.2% (34/2595) for FS vs 2.7% (69/2595) for CTC (RR 2.06; 95% CI 1.37 to 3.10). Conclusions and relevance Participation and DR for FS and CTC were comparable. AN DR was twice as high in the proximal colon and lower in the distal colon with CTC than with FS. Men were more likely to participate in CTC screening. Trial registration number NCT01739608; Preresults.

Original languageEnglish
Pages (from-to)1434-1440
Number of pages6
Publication statusPublished - Aug 2017

ASJC Scopus subject areas

  • Gastroenterology


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