Objective: To systematically evaluate whether immunochemical fecal occult blood tests (iFOBT) could improve clinical performance and test accuracy in screening and surveillance for advanced colorectal neoplasms.
Methods: Eligible articles were identified by searches of electronic databases. All randomized trials and diagnostic cohort trials directly comparing iFOBT with guaiac-based FOBT (gFOBT) were included. A statistical analysis was performed using RevMan 4.2.8. A sensitivity, specificity and summary receiver operating characteristic curve was performed using Meta Disc.
Results: We identified five randomized trials and 11 diagnostic cohort trials. In the randomized trials, the detection rates of advanced colorectal neoplasms with iFOBT or gFOBT were 2.23 percent and 1.24 percent, respectively. The pooled odds ratio (OR) was 1.50 (95% CI 0.94-2.39). In cohort trials, the advanced neoplasm detection rates of iFOBT or gFOBT were 1.44 percent and 0.50 percent (OR 1.99, 95% CI 1.24-3.19) in the average-risk screened population, and were 8.8 percent and 7.1 percent (OR 1.27, 95% CI 1.01-1.60) in diagnosed patients scheduled for colonoscopy. The sensitivity of iFOBT (0.67, 95% CI 0.61-0.73) was superior to that of gFOBT (0.54, 95% CI 0.48-0.60), as well as the specificities (0.85, 95% CI 0.83-0.87 vs 0.80, 95% CI 0.78-0.82) and positive predictive values (0.41 vs 0.29) in cohort trials of diagnosed patients.
Conclusion: Our review suggests that iFOBT could perform better in increasing the detection rate of advanced colorectal neoplasm than gFOBT and possesses higher sensitivity and specificity in the surveillance of advanced colorectal neoplasm for patients.