[Accuracy of immunochemical faecal occult blood test for colorectal cancer: meta-analysis]

To assess the accuracy of immunological fecal occult blood test (iFOBT) for detection of colorectal cancer (CRC).

A total of 1 197 studies published before June 2014 were selected from PubMed and Embase and 17 of which were finally included in this meta-analysis. A bivariate mixed-effects models was used for overall value merging and heterogeneity testing. In addition to the overall sensitivity and specificity, the analyses were also performed among certain subgroups, including a "colonoscopy group" (all were referred for colonoscopy diagnosis regardless screening results) and a "follow-up group" (only the screening positive were referred and all were then followed up), a qualitative group and a quantitative group (classified by the way of iFOBT result reading).

A total of 161 502 subjects aged from 48 to 63 years were included in the analysis. IFOBT had an overall integrated sensitivity of 0.85 (95% CI: 0.79-0.89) (heterogeneity test: Q = 59.67, P < 0.001) and an overall integrated specificity of 0.93 (95% CI: 0.92-0.94) (heterogeneity test: Q = 1 722.53, P < 0.001) for detection of CRC. In the subgroup analysis, it was found that in the "colonoscopy group" and in the "follow-up group", the sensitivity were 0.81 (95%CI: 0.73-0.87) and 0.88 (95% CI: 0.81-0.92), respectively; the specificity were 0.92 (95% CI: 0.89-0.93) and 0.95 (95% CI: 0.94-0.96), respectively. It was also found that in the qualitative group and the quantitative group, the sensitivity were 0.84 (95% CI: 0.76-0.90) and 0.86 (95% CI: 0.78-0.92), respectively; the specificity were 0.94 (95% CI: 0.91-0.96) and 0.93 (95% CI: 0.91-0.94), respectively.

IFOBT had high overall sensitivity and specificity for detecting colorectal cancer.