Carlo Senore MD, Abstract Co-Author: Nothing to Disclose

Gabriella Iussich MD, Abstract Co-Author: Consultant, im3D SpA

Loredana Correale PhD, Abstract Co-Author: Researcher, im3D SpA

Nereo Segnan, Abstract Co-Author: Nothing to Disclose

Cesare Hassan, Abstract Co-Author: Nothing to Disclose

Daniele Regge MD, Presenter: Nothing to Disclose

Paolo Falco, Abstract Co-Author: Employee, im3D SpA

Alberto Bert PhD, Abstract Co-Author: Employee, im3D SpA

To compare the participation rate of Flexible Sigmoidoscopy (FS) vs. CT Colonography (CTC) in a population-based colorectal cancer (CRC) screening program in Turin, Italy. 

A sample of 58 years olds in the general population living in Turin, Italy were randomly allocated (1:1) to be invited by mail for primary screening with FS or CTC. Those with a history of CRC, adenomas, inflammatory bowel disease, recent colonoscopy, or two first-degree relatives with CRC were ineligible. Non-responders to invitation for FS screening were re-invited to attend for screening with CTC or immunological Fecal Occult Blood Test (FOBT). The primary outcome was screening participation rate, defined as numbers of invitees undergoing to the screening relative to the total number of invitees. Participation rates were also compared in a multivariate model to assess the effect of covariates (sex, screening arm). Data on reasons for non-participation were collected.  

Of the 1984 eligible subjects included in the study, 995 and 989 were randomly assigned to CTC and FS arm, respectively. After excluding 27 people who could not be traced (1.4% across intervention groups), the participation rate following the first invitation and mail remainder was 27.1% (265/977) for FS and 30.5% (299/980) for CTC (P=0.09). Participation in screening with CTC was significantly better than with FS (34%, 95% CI: 30-39% vs. 26%, 95% CI: 22-31; OR, 1.6; 95% CI: 1.1-2.3; P=0.01) among men, while no difference between CTC and FS screening was observed among women (27%, 95% CI: 23-31% vs. 28%; 95% CI:24-32; OR, 0.91; 95% CI: 0.7-1.2; P=0.53). Invitation for FS non-responders to undergo screening with CTC or FOBT increased participation (80-100 days after invitation) by 5% (18 of 330 invitees) and 4.8% (16 of 330 invitees), respectively.  

A numerical trend of increased participation in CTC vs. FS screening was seen. Moreover, men were significantly more likely than women to adhere to screening with CTC than with FS. 

Our study showed a higher participation of men in CTC screening (vs. FS screening). Additional effort may be needed to improve participation of women in CRC screening  regardless of screening strategy. 

Senore, C, Iussich, G, Correale, L, Segnan, N, Hassan, C, Regge, D, Falco, P, Bert, A, Screening for Colorectal Cancer: A Randomized Trial Comparing Patient Response of Sigmoidoscopy vs. CT Colonography.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14004128.html