Comparison of the yield from two faecal immunochemical tests at identical cutoff concentrations - a randomized trial in Latvia.
OBJECTIVE
We have compared the performance of two faecal immunochemical tests (FIT) in an average-risk population.


METHODS
Altogether, 10 000 individuals aged 50-74 were selected randomly from the population of Latvia in 2011 and assigned randomly either to OC-Sensor or to FOB Gold single-time testing. Positivity of the test, frequency of colonic lesions, number needed to screen (NNscreen) and scope for the detection of an advanced neoplasm (cancer and advanced adenoma) were compared between the tests using the same cutoff concentrations in µg/g faeces. Confidence intervals (CIs) at 95% were calculated.


RESULTS
Positivity with the cutoff set at 10 µg/g faeces was 12.8% (95% CI: 11.4-14.2) for FOB Gold and 8.3% (95% CI: 7.2-9.4) for OC-Sensor (P<0.001). Positivity was higher in men and the older age groups. Colonoscopy compliance was 55.5%. There was no significant difference between the two tests at comparable cutoff concentrations in µg/g, colonoscopy attendance rate or colonoscopy results. For advanced neoplasm detection, there was no significant difference in number needed to scope and NNscreen at a cutoff of 10 µg/g faeces; however, lower NNscreen was required to detect advanced neoplasms with the FOB Gold test at increased cutoff concentrations.


CONCLUSIONS
Different quantitative FIT systems may report different positivity rate at identical cutoff concentrations, which has to be considered when implementing the use of FIT in national screening programmes.
aDepartment of Medicine, Riga East University Hospital bDepartment of Medicine, University of Latvia cDepartment of Medicine, Riga East University Hospital, University of Latvia, Digestive Diseases Centre Gastro dDigestive Diseases Centre Gastro eDigestive Diseases Centre Gastro, Riga Stradins University, Riga, Latvia.
Daiga
D
Santare
Ilona
I
Kojalo
Inta
I
Liepniece-Karele
Ilze
I
Kikuste
Ivars
I
Tolmanis
Inese
I
Polaka
Uldis
U
Vikmanis
Viesturs
V
Boka
Marcis
M
Leja
D000236:Adenoma / Q000175:diagnosis* / Q000473:pathology; D000368:Aged; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007844:Latvia; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D009780:Occult Blood; D011237:Predictive Value of Tests; D015203:Reproducibility of Results