Comparison Between Faecal Occult Blood Test (FOBT), Computed Tomographic Colonography (CTC) With Computer Aided Diagnosis (CAD) and Colonoscopy as a Primary Screening Test for Colorectal Cancer. Validation of a Teleradiology Model. Biological Banking in Subjects Recruited for Colonoscopy or CTC.
- To compare the participation rate to faecal occult blood test (FOBT), computed
tomographic colonography (CTC) and colonoscopy (CO) as a primary screening test in a
population-based programme for colorectal cancer.
- To compare the participation rate to CTC with reduced cathartic preparation versus CTC
with standard bowel preparation.
- To compare the detection rate for cancer or advanced adenomas of CTC with computer
aided diagnosis (CAD) versus three rounds of FOBT every second year.
- To evaluate referral rate for colonoscopy induced by primary CTC versus three rounds of
FOBT every second year.
- To compare costs of the three screening strategies.
- To compare the expected and perceived discomfort of colonoscopy and computed
tomographic colonography as assessed with a structured questionnaire.
- To evaluate the rate of complications in each group.
- To validate a teleradiology model for computed tomographic colonography.
- To create a biological bank of blood and stool specimens from subjects who undergo
computed tomographic colonography, primary colonoscopy and second level colonoscopy.
14,000 subjects aged 55-64 years, living in the Florence District and never screened for
colorectal cancer, will be randomized in 3 arms:
- group 1 (5,000 persons) invited to CTC (divided into: subgroup 1A with reduced
cathartic preparation and subgroup 1B with standard bowel preparation);
- group 2 (8,000 persons) invited to biannual FOBT for 3 rounds;
- group 3 (1,000 persons) invited to CO.
Subjects of each group will be invited by mail to undergo the selected test. Individuals of
each group will receive an invitation letter and an information leaflet, containing
information about colorectal cancer, importance of screening, and advantages and possible
risks of the selected test.
Invitation letter for the FOBT group contains instructions on how to pick-up the kit test at
the nearest pharmacy. The FOBT screening test adopted is OC-SENSOR DIANA (Eiken Chemical
Co., Tokyo, Japan), a quantitative, completely automated immunochemical test, based on latex
agglutination. Positivity threshold is set at 100 ng/ml of sample solution. Invited subjects
are asked to collect a single sample of faeces, without dietary restrictions. Sample are
retuned according to the routine procedure of Florence screening programme.
Invitation letter for CTC and colonoscopy contains a phone number and an email address of
the screening centre. All invitees have the option to call or send an email to the screening
centre in order to receive an appointment for a prior consultation. All non-responders will
receive a remainder by mail after three months. Non-responders to reminder will be invited
to FOBT according with current screening procedure.
Subjects who accept invitation for CTC or CO will have a consultation at the screening
centre with a trained nurse. During the consultation subjects will be informed about the
study protocol, the screening examination to which they are invited, the bowel preparation,
and the management in case of positive results. All subjects tested positive to FOBT or CTC
(mass or at least one polyp ≥ 6 mm) will be invited to undergo total colonoscopy. Then,
subjects will be scheduled for the selected examination (CTC or CO).
Allocation: Randomized, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Screening
Participation rate to faecal occult blood test (FOBT), computed tomographic colonography (CTC) and colonoscopy
Stefano Milani, MD
University of Florence
Italy: National Institute of Health