Comparison of the performance of guaiac‐based and two immunochemical fecal occult blood tests for identifying advanced colorectal neoplasia in T aiwan

Objectives We aimed to evaluate the performance of fecal occult blood tests (FOBT) for the screening of colorectal cancer (CRC). Methods We selected participants from a medical center in Taiwan, China from N ovember 2009 to J une 2011. All participants underwent screening colonoscopy and were asked to provide their stool samples for qualitative immunochemical FOBT ( qlFIT ), quantitative immunochemical FOBT ( qnFIT ) and the guaiac‐based FOBT ( GT ). The receiver operating characteristic curve was utilized to determine the optimal cut‐off value of qnFIT . We measured the detection ability of the FOBT for colonic polypoid lesions. Results In all, 699 participants were enrolled in this study. For qnFIT , we found increased levels of fecal hemoglobin in participants with polyps ≥10 mm (251.0 ng/mL), villous‐containing adenomas (98.7 ng/mL) and advanced adenomas (187.9 ng/mL). The optimal cut‐off value for qnFIT was 25 ng/mL for detecting advanced colorectal neoplasms ( ACRN ). All three FOBT had a similar but low estimate in detecting small and tubular adenomatous polyps. The qnFIT had a better detection ability for large adenomas (positive likelihood ratio [ PLR ], 5.6 vs 3.1 vs 0.3) and adenomas with villous‐components ( PLR 3.7 vs 3.3 vs 0.3) than qlFIT and GT . For the ACRN group, qnFIT also showed the best screening ability with a sensitivity of 56.8%, accuracy of 86.7% and PLR 5.0. Conclusions Both qnFIT and qlFIT perform better than GT in detecting advanced adenomas and CRC in the T aiwanese population.