title: Comparing CT colonography and flexible sigmoidoscopy: a randomised trial within a population-based screening programme.
abstract: 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.
  
  
  
  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).
  
  
  
  Participation rate (proportion of invitees examined); DR of advanced adenomas or CRC (advanced neoplasia (AN)).
  
  
  
  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).
  
  
  
  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.
  
  
  
  NCT01739608; Pre-results.
authors.affiliation: Candiolo Cancer Institute-FPO, IRCCS, Candiolo, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Regge
authors.affiliation: Ospedale Regionale di Locarno La Carità, Locarno, Switzerland.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Iussich
authors.affiliation: AOU S Giovanni Battista-CPO Piemonte, SCDO Epidemiologia dei Tumori 2, Turin, Italy.
authors.forename: Nereo
authors.initials: N
authors.lastname: Segnan
authors.affiliation: im3D S.p.A., Turin, Italy.|Endoscopy Unit, Nuovo Regina Margherita Hospital, Rome, Italy.
authors.forename: Loredana
authors.initials: L
authors.lastname: Correale
authors.affiliation: AOU Città della Salute e della Scienza, CPO Piemonte, SCDO Epidemiologia screening e registro tumori, Turin, Italy.
authors.forename: Cesare
authors.initials: C
authors.lastname: Hassan
authors.affiliation: Endoscopy Unit, Ospedale San Giovanni Antica Sede, Turin, Italy.
authors.forename: Arrigo
authors.initials: A
authors.lastname: Arrigoni
authors.affiliation: Radiology Unit, Fondazione Salvatore Maugeri, IRCCS, Istituto Scientifico di Veruno, Veruno, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Asnaghi
authors.affiliation: Screening Unit, ASL Novara, Novara, Italy.
authors.forename: Piero
authors.initials: P
authors.lastname: Bestagini
authors.affiliation: Endoscopy and Gastroenterology Unit, U.l.s.s. 20 Verona, Ospedale G. Fracastoro-San Bonifacio, Verona, Italy.
authors.forename: Gianmarco
authors.initials: G
authors.lastname: Bulighin
authors.affiliation: Radiology Unit, Department of Surgical Science, University of Torino, A.O.U. Città della Salute e della Scienza di Torino, Turin, Italy.
authors.forename: Maria Carla
authors.initials: MC
authors.lastname: Cassinis
authors.affiliation: Endoscopy and Gastroenterology Unit, U.l.s.s. 20 Verona, Ospedale G. Fracastoro-San Bonifacio, Verona, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Ederle
authors.affiliation: Radiology Unit, Department of Surgical Science, University of Torino, A.O.U. Città della Salute e della Scienza di Torino, Turin, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Ferraris
authors.affiliation: Candiolo Cancer Institute-FPO, IRCCS, Candiolo, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Galatola
authors.affiliation: Radiology Unit, Ospitale Mauriziano, Turin, Italy.
authors.forename: Teresa
authors.initials: T
authors.lastname: Gallo
authors.affiliation: Radiology Unit, Department of Surgical Science, University of Torino, A.O.U. Città della Salute e della Scienza di Torino, Turin, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Gandini
authors.affiliation: Radiology Unit, Ospedale San Giovanni Antica Sede, Turin, Italy.
authors.forename: Licia
authors.initials: L
authors.lastname: Garretti
authors.affiliation: Radiology Unit, Department of Surgical Science, University of Torino, A.O.U. Città della Salute e della Scienza di Torino, Turin, Italy.
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Martina
authors.affiliation: Radiology Unit, Ospedale degli Infermi, Biella, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Molinar
authors.affiliation: Radiology Unit, Azienda Ospedaliera Universitaria Integrata di Verona, Verona, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Montemezzi
authors.affiliation: im3D S.p.A., Turin, Italy.|Endoscopy Unit, Nuovo Regina Margherita Hospital, Rome, Italy.
authors.forename: Lia
authors.initials: L
authors.lastname: Morra
authors.affiliation: Radiology Unit, Azienda Ospedaliera Universitaria Integrata di Verona, Verona, Italy.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Motton
authors.affiliation: AOU Ospedale Maggiore della Carità, Novara, Italy.
authors.forename: Pietro
authors.initials: P
authors.lastname: Occhipinti
authors.affiliation: Radiology Unit, Azienda Ospedaliera Universitaria Integrata di Verona, Verona, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Pinali
authors.affiliation: Radiology Unit, Azienda Ospedaliera Universitaria Integrata di Verona, Verona, Italy.
authors.forename: Gian Alberto
authors.initials: GA
authors.lastname: Soardi
authors.affiliation: AOU S Giovanni Battista-CPO Piemonte, SCDO Epidemiologia dei Tumori 2, Turin, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Senore
mesh_terms: D000236:Adenoma / Q000000981:diagnostic imaging* / Q000473:pathology; D003111:Colonic Polyps / Q000000981:diagnostic imaging*; D023881:Colonography, Computed Tomographic; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D055088:Early Detection of Cancer / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010342:Patient Acceptance of Health Care / Q000706:statistics & numerical data; D012737:Sex Factors; D012812:Sigmoidoscopy
keywords: COLONIC NEOPLASMS; COLORECTAL CANCER SCREENING