A multicenter prospective study of immunochemical fecal occult blood testing for colorectal cancer detection.
BACKGROUND
Colorectal cancer (CRC) screening by guaiac fecal occult blood test (gFOBT) can reduce the mortality of CRC. The new immunochemical fecal occult blood test (iFOBT) has possibly improved sensitivity and specificity without any dietary restriction.


OBJECTIVE
The present study aimed to evaluate the sensitivity, specificity, positive and negative predictive values of iFOBT for CRC detection compared to the colonoscopic and pathologic findings in known CRC cases.


METHODS
A multicenter prospective study was conducted in three university hospitals in Bangkok, Thailand, between May and August 2006. Stool samples from 100 histologically-proven CRC patients and 64 control cases with normal colonoscopic findings were collected for iFOBT (OC-Light, Nagase, Singapore) without dietary restriction.


RESULTS
The results showed the sensitivity, specificity, positive and negative predictive values of iFOBT for CRC detection to be 91.0% (95% CI: 83.8-95.2), 93.8% (95% CI: 85.0-97.5), 95.8% (95% CI: 89.7-98.4) and 87.0% (95% CI: 77.0-93.0) respectively. The sensitivity for CRC according to Dukes'stage was 71.4% (Dukes' A), 88.0% (Dukes' B), and 96.7% (Dukes' C or D). The sensitivity was 84.2% for proximal colon and 92.6% for distal colon and rectum.


CONCLUSIONS
The iFOBT revealed high sensitivity, specificity, positive and negative predictive values for CRC detection without dietary restriction. It should be considered as a noninvasive tool for CRC detection.
Lohsiriwat
Varut
V
Department of Surgery, Faculty of Medicine, Siriraj Hospital, Mahidol University, Prannok Rd, Bangkok 10700, Thailand. sislr@mahidol.ac.th
Thavichaigarn
Parinya
P
Awapittaya
Burin
B
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000503:physiopathology; D005243:Feces; D005260:Female; D006305:Health Status Indicators; D006785:Hospitals, University; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009780:Occult Blood; D011446:Prospective Studies; D018434:Sickness Impact Profile