Article Text

Download PDFPDF
Original article
Comparing CT colonography and flexible sigmoidoscopy: a randomised trial within a population-based screening programme
  1. Daniele Regge1,
  2. Gabriella Iussich2,
  3. Nereo Segnan3,
  4. Loredana Correale4,5,
  5. Cesare Hassan6,
  6. Arrigo Arrigoni7,
  7. Roberto Asnaghi8,
  8. Piero Bestagini9,
  9. Gianmarco Bulighin10,
  10. Maria Carla Cassinis11,
  11. Andrea Ederle10,
  12. Andrea Ferraris11,
  13. Giovanni Galatola1,
  14. Teresa Gallo12,
  15. Giovanni Gandini11,
  16. Licia Garretti13,
  17. Maria Cristina Martina11,
  18. Daniela Molinar14,
  19. Stefania Montemezzi15,
  20. Lia Morra4,5,
  21. Massimiliano Motton15,
  22. Pietro Occhipinti16,
  23. Lucia Pinali15,
  24. Gian Alberto Soardi15,
  25. Carlo Senore3
    1. 1 Candiolo Cancer Institute-FPO, IRCCS, Candiolo, Italy
    2. 2 Ospedale Regionale di Locarno La Carità, Locarno, Switzerland
    3. 3 AOU S Giovanni Battista-CPO Piemonte, SCDO Epidemiologia dei Tumori 2, Turin, Italy
    4. 4 im3D S.p.A., Turin, Italy
    5. 5 Endoscopy Unit, Nuovo Regina Margherita Hospital, Rome, Italy
    6. 6 AOU Città della Salute e della Scienza, CPO Piemonte, SCDO Epidemiologia screening e registro tumori, Turin, Italy
    7. 7 Endoscopy Unit, Ospedale San Giovanni Antica Sede, Turin, Italy
    8. 8 Radiology Unit, Fondazione Salvatore Maugeri, IRCCS, Istituto Scientifico di Veruno, Veruno, Italy
    9. 9 Screening Unit, ASL Novara, Novara, Italy
    10. 10 Endoscopy and Gastroenterology Unit, U.l.s.s. 20 Verona, Ospedale G. Fracastoro—San Bonifacio, Verona, Italy
    11. 11 Radiology Unit, Department of Surgical Science, University of Torino, A.O.U. Città della Salute e della Scienza di Torino, Turin, Italy
    12. 12 Radiology Unit, Ospitale Mauriziano, Turin, Italy
    13. 13 Radiology Unit, Ospedale San Giovanni Antica Sede, Turin, Italy
    14. 14 Radiology Unit, Ospedale degli Infermi, Biella, Italy
    15. 15 Radiology Unit, Azienda Ospedaliera Universitaria Integrata di Verona, Verona, Italy
    16. 16 AOU Ospedale Maggiore della Carità, Novara, Italy
    1. Correspondence to Dr Carlo Senore, AOU Città della Salute e della Scienza, CPO Piemonte, SCDO Epidemiologia, screening e registro Tumori. Via Cavour 31, 10123, Turin, Italy; carlo.senore{at}


    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; Pre-results.


    Statistics from

    Request Permissions

    If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.