Fecal immunochemical test (FIT) sensitivity for colorectal cancer (CRC) is often cited at about 80%, using the 20 microgram Hgb/g feces cut-off. However, it is important to know the stage-specific performance because detection of early stages has greater value than detection of late stages.
In a systematic review and meta-analysis of 44 studies, the pooled sensitivity estimates for stages I, II, III, and IV were 73%, 80%, 82%, and 79%, respectively, with significant differences between stages I versus II and I versus III. The pooled sensitivities by T stage showed more striking differences: the respective sensitivities for T1, T2, T3, and T4 were 40%, 79%, 83%, and 66%, with significantly lower sensitivity for T1 than each of the higher T stages.
This analysis is informative, suggesting that FIT sensitivity for T1 cancers is comparable to FIT sensitivity for advanced adenomas. The study is likely to be viewed as a modest setback to the rising enthusiasm for FIT as a CRC screening test.
Niedermaier T, Balavarca Y, Brenner H. Stage-specific sensitivity of fecal immunochemical tests for detection colorectal cancer: systematic review and meta-analysis. Am J Gastroenterol
2019 Dec 10. (Epub ahead of print) (https://doi.org/10.14309/ajg.0000000000000465