Comparing attendance and detection rate of colonoscopy with sigmoidoscopy and FIT for colorectal cancer screening.
OBJECTIVE
We conducted a study to estimate population coverage and detection rate (DR) achievable through different strategies of colorectal cancer (CRC) screening.


METHODS
A population-based multicenter randomized trial comparing 3 strategies was used: (1) biennial immunologic fecal occult blood test (FIT), (2) "once only" sigmoidoscopy (FS), and (3) "once only" colonoscopy (TC). A random sample of men and women, aged 55 to 64 years, was drawn from general practitioners' (GP) rosters. Eligible subjects, randomized within GP, were mailed a personal invitation. Nonresponders in groups 2 and 3 were invited again at 12 and 24 months. Screenees with "high-risk" distal polyps (villous component >20%, high-grade dysplasia, CRC, size >or=10 mm, >2 adenomas) at FS, or with positive FIT, were referred for TC.


RESULTS
The attendance rate was 32.3% (1965/6075) for FIT, 32.3% (1944/6018) for FS, 26.5% (1597/6021) for TC. FIT detected 2 patients with CRC (0.1%) and 21 with an advanced adenoma (1.1%). The corresponding figures were as follows: 12 (0.6%) and 86 (4.5%) patients, respectively, for FS; 13 (0.8%) and 100 (6.3%) patients, respectively, for TC. To detect 1 advanced neoplasm, it would be necessary to invite 264 people with FIT, 60 with FS, 53 with TC. FS would have detected 27.3% of the proximal advanced neoplasms detected at TC. Assuming the same participation rate at TC as at FS, 48 TCs would be necessary to detect 1 additional advanced neoplasm missed by FS.


CONCLUSIONS
When participants are offered 1 screening test, participation is lower in a TC than in an FS program. However, DR of advanced neoplasia is higher with TC.
Segnan
Nereo
N
CPO Piemonte, Torino, Italy. nereo.segnan@cpo.it
Senore
Carlo
C
Andreoni
Bruno
B
Azzoni
Alberto
A
Bisanti
Luigi
L
Cardelli
Alessandro
A
Castiglione
Guido
G
Crosta
Cristiano
C
Ederle
Andrea
A
Fantin
Alberto
A
Ferrari
Arnaldo
A
Fracchia
Mario
M
Ferrero
Franco
F
Gasperoni
Stefano
S
Recchia
Serafino
S
Risio
Mauro
M
Rubeca
Tiziana
T
Saracco
Giorgio
G
Zappa
Marco
M
D000236:Adenoma / Q000175:diagnosis; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000453:epidemiology; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D009780:Occult Blood; D010349:Patient Compliance; D018579:Patient Selection; D015995:Prevalence; D012812:Sigmoidoscopy