Colorectal Cancer Screening With Traditional and New-generation Fecal Immunochemical Tests: A Critical Review of Fecal Occult Blood Tests

Previous randomized studies suggest that fecal occult blood test (FOBT) screening can reduce mortality from colorectal cancer (CRC). Our aim was to review the current status of FOBTs in CRC screening. FOB is measured using either the traditional guaiac-based tests or more recently introduced fecal immunochemical tests (FITs). FITs have several advantages over guaiac-based FOBTs, including higher sensitivity and specificity, resulting in improved clinical performance and higher efficiency. Another advantage in population screening according to European Guidelines for quality assurance in CRC screening is that FITs can be automated and user can adjust the cutoff at which a positive result is reported. In population-based screening, all those testing positively with any FOBT should be referred for colonoscopy. Conclusion: Although a plethora of FOBTs are available on the market, relatively few have been extensively tested for clinical sensitivity and specificity in CRC screening. Current data imply that new FITs have superior test characteristics as compared with guaiac-based FOBTs. The latest development in the field is represented by the proteomic-based tests that may further reduce false-negative rates in CRC screening. Simple stool sample preservation and automatic analysis are other important issues in population-based screening for CRC.