Prescreening evaluation of a brush-based faecal immunochemical test for haemoglobin.
OBJECTIVE
To undertake a prescreening evaluation of a new brush-based faecal immunochemical test for haemoglobin, relative to a traditional spatula-sampling immunochemical test.


METHODS



METHODS
Patients aged between 24 and 90 years, scheduled to undergo diagnostic colonoscopy in two major urban hospitals, for a range of clinical indications.


METHODS
Patients sampled three stools using a spatula for the reference FlexSure OBT test and two stools using a brush for the InSure test; order of sampling was randomised. Faecal haemoglobin was quantified by a modified InSure in a subset of patients to determine whether brush-sampling allowed discrimination between groups.


METHODS
Sensitivity for cancer or adenoma; false-positive rate in normals. Faecal haemoglobin levels. Preference for sampling method.


RESULTS
InSure and FlexSure OBT did not differ in their sensitivities for cancer (27/36, 75% vs 29/36, 80.5%, respectively), adenomas >or= 10 mm (12/29, 41.4% vs 13/29, 44.8%) or adenomas <10 mm (each 8/56, 14.3%). Likewise, false-positive rates in normals were similar: 4/179 (2.2%) and 5/179 (2.8%) respectively (specificities of 97.8% and 97.2%, respectively). Levels of faecal haemoglobin were highest in those with cancers; those with adenomas had intermediate levels which were also significantly higher than those in normals. The brush sampling method was preferred by 38/46 (82.6%), while 4/46 (8.7%) preferred the spatula (p<0.00001).


CONCLUSIONS
InSure is as sensitive and specific as FlexSure OBT for faecal haemoglobin. The novel stool-sampling method of InSure allows discrimination between normals and classes of neoplasia, and is highly preferred. The brush-sampling faecal immunochemical test InSure should now be evaluated in a screening population.
Young
G P
GP
Department of Medicine, Flinders University of South Australia, Bedford Park, SA, Australia. garaeme.young@flinders.edu.au
St John
D J B
DJ
Cole
S R
SR
Bielecki
B E
BE
Pizzey
C
C
Sinatra
M A
MA
Polglase
A L
AL
Cadd
B
B
Morcom
J
J
D000236:Adenoma / Q000209:etiology / Q000473:pathology; D000328:Adult; D000368:Aged; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000209:etiology / Q000473:pathology; D043963:Diverticulosis, Colonic / Q000473:pathology; D005189:False Positive Reactions; D005243:Feces / Q000737:chemistry; D005260:Female; D006454:Hemoglobins / Q000032:analysis*; D006484:Hemorrhoids / Q000473:pathology; D006801:Humans; D007159:Immunologic Tests / Q000295:instrumentation / Q000379:methods*; D008297:Male; D008403:Mass Screening / Q000379:methods* / Q000639:trends; D008875:Middle Aged; D009780:Occult Blood; D010358:Patient Participation; D011933:Reagent Kits, Diagnostic; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D006454:Hemoglobins; D011933:Reagent Kits, Diagnostic