title: Once-only sigmoidoscopy in colorectal cancer screening: follow-up findings of the Italian Randomized Controlled Trial--SCORE.
abstract: BACKGROUND
  A single flexible sigmoidoscopy at around the age of 60 years has been proposed as an effective strategy for colorectal cancer (CRC) screening.
  
  
  METHODS
  We conducted a randomized controlled trial to evaluate the effect of flexible sigmoidoscopy screening on CRC incidence and mortality. A questionnaire to assess the eligibility and interest in screening was mailed to 236,568 men and women, aged 55-64 years, who were randomly selected from six trial centers in Italy. Of the 56,532 respondents, interested and eligible subjects were randomly assigned to the intervention group (invitation for flexible sigmoidoscopy; n = 17,148) or the control group (no further contact; n = 17,144), between June 14, 1995, and May 10, 1999. Flexible sigmoidoscopy was performed on 9911 subjects. Intention-to-treat and per-protocol analyses were performed to compare the CRC incidence and mortality rates in the intervention and control groups. Per-protocol analysis was adjusted for noncompliance.
  
  
  RESULTS
  A total of 34,272 subjects (17,136 in each group) were included in the follow-up analysis. The median follow-up period was 10.5 years for incidence and 11.4 years for mortality; 251 subjects were diagnosed with CRC in the intervention group and 306 in the control group. Overall incidence rates in the intervention and control groups were 144.11 and 176.43, respectively, per 100,000 person-years. CRC-related death was noted in 65 subjects in the intervention group and 83 subjects in the control group. Mortality rates in the intervention and control groups were 34.66 and 44.45, respectively, per 100,000 person-years. In the intention-to-treat analysis, the rate of CRC incidence was statistically significantly reduced in the intervention group by 18% (rate ratio [RR] = 0.82, 95% confidence interval [CI] = 0.69 to 0.96), and the mortality rate was non-statistically significantly reduced by 22% (RR = 0.78; 95% CI = 0.56 to 1.08) compared with the control group. In the per-protocol analysis, both CRC incidence and mortality rates were statistically significantly reduced among the screened subjects; CRC incidence was reduced by 31% (RR = 0.69; 95% CI = 0.56 to 0.86) and mortality was reduced by 38% (RR = 0.62; 95% CI = 0.40 to 0.96) compared with the control group.
  
  
  CONCLUSIONS
  A single flexible sigmoidoscopy screening between ages 55 and 64 years was associated with a substantial reduction of CRC incidence and mortality.
authors.affiliation: Centro di Prevenzione Oncologica Piemonte and S. Giovanni University Hospital, Turin, Italy. nereo.segnan@cpo.it
authors.forename: Nereo
authors.initials: N
authors.lastname: Segnan
authors.forename: Paola
authors.initials: P
authors.lastname: Armaroli
authors.forename: Luigina
authors.initials: L
authors.lastname: Bonelli
authors.forename: Mauro
authors.initials: M
authors.lastname: Risio
authors.forename: Stefania
authors.initials: S
authors.lastname: Sciallero
authors.forename: Marco
authors.initials: M
authors.lastname: Zappa
authors.forename: Bruno
authors.initials: B
authors.lastname: Andreoni
authors.forename: Arrigo
authors.initials: A
authors.lastname: Arrigoni
authors.forename: Luigi
authors.initials: L
authors.lastname: Bisanti
authors.forename: Claudia
authors.initials: C
authors.lastname: Casella
authors.forename: Cristiano
authors.initials: C
authors.lastname: Crosta
authors.forename: Fabio
authors.initials: F
authors.lastname: Falcini
authors.forename: Franco
authors.initials: F
authors.lastname: Ferrero
authors.forename: Adriano
authors.initials: A
authors.lastname: Giacomin
authors.forename: Orietta
authors.initials: O
authors.lastname: Giuliani
authors.forename: Alessandra
authors.initials: A
authors.lastname: Santarelli
authors.forename: Carmen Beatriz
authors.initials: CB
authors.lastname: Visioli
authors.forename: Roberto
authors.initials: R
authors.lastname: Zanetti
authors.forename: Wendy S
authors.initials: WS
authors.lastname: Atkin
authors.forename: Carlo
authors.initials: C
authors.lastname: Senore
mesh_terms: D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000453:epidemiology* / Q000401:mortality / Q000517:prevention & control; D055088:Early Detection of Cancer / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007558:Italy / Q000453:epidemiology; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D016017:Odds Ratio; D010349:Patient Compliance; D012812:Sigmoidoscopy / Q000592:standards; D011795:Surveys and Questionnaires; D013997:Time Factors