Sensitivity of immunochemical fecal occult blood test to small colorectal adenomas.
BACKGROUND
Although the immunochemical fecal occult blood test (FOBT) is reportedly more sensitive to large adenomas or colorectal cancer (CRC) than the guaiac-based FOBT, the sensitivity of the immunochemical FOBT to small adenomas has scarcely been reported. Previous reports have indicated that the guaiac-based FOBT can detect small adenomas only by serendipity.


OBJECTIVE
To investigate the sensitivity of immunochemical FOBT to small adenomas using a large-scale cohort.


METHODS
We analyzed 21,805 consecutively enrolled asymptomatic persons who underwent colonoscopy and immunochemical FOBT.


RESULTS
The sensitivity to adenomas </=9 mm was significantly higher than the false-positive rate as revealed by analysis of all eligible subjects (7.0%vs 4.5%, P < 0.001). In men, the sensitivity was superior to the false-positive rate and increased with age (<50 yr 6.1% and >60 yr 11.3%). On the other hand, the sensitivity in women was not significantly different from the false-positive rate in any generation (5.1%vs 4.7% for all eligible women, P= 0.72).


CONCLUSIONS
Immunochemical FOBT detected a small percentage of small adenomas in men at a rate that is significantly higher than the false-positive rate. Studies comparing the guaiac and immunochemical FOBTs using the end point of CRC-related death are expected.
Morikawa
Tamiya
T
Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
Kato
Jun
J
Yamaji
Yutaka
Y
Wada
Ryoichi
R
Mitsushima
Toru
T
Sakaguchi
Kohsaku
K
Shiratori
Yasushi
Y
D000236:Adenoma / Q000175:diagnosis* / Q000473:pathology; D000328:Adult; D015331:Cohort Studies; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D006801:Humans; D007120:Immunochemistry; D008297:Male; D008875:Middle Aged; D009780:Occult Blood; D012680:Sensitivity and Specificity