Diagnostic Accuracy of Fecal Immunochemical Test (FIT) in Bleed-positive and Bleed-negative Colorectal Cancer (CRC) Among a Cohort of 5,090 Subjects who Participated in the Colorectal Neoplasia (CRN) Screening in Brazil.

BACKGROUND/AIM: This study assessed the diagnostic accuracy (DA) of fecal immunochemical test (FIT) ColonView (CV) and guaiac-based fecal occult blood test (HemoccultSENSA) among bleed-positive (history or signs of intestinal bleeding) and bleed-negative participants (no history or signs of intestinal bleeding) (n=5,090) in colorectal neoplasia (CRN) screening in Brazil. PATIENTS AND METHODS: The eligible patients for the study (n=506) collected three consecutive stool samples, to be analyzed by both assays (CV, SENSA). Finally, 421/5090 (8.3%) patients returned both samples, which were subjected to final analysis. Receiver operating characteristic (ROC) analysis with different cut-offs was performed to assess the DA. RESULTS: The area under curve (AUC) values for i) visually analyzed (VA) CV for bleed-positive CRC, ii) automatically analyzed (AA) CV for bleed-positive CRC, iii) VA CV for bleed-negative CRC, and iv) AA CV for bleed-negative CRC as endpoints were as follows: i) AUC=0.864, ii) AUC=0.933, iii) AUC=0.836, and iv) AUC=0.892. In roccomp analysis, the differences in AUC values were: between i) and ii) p=0.068; between i) and iii) p=0.497; between i) and iv) p=0.488; between ii) and iii) p=0.0058; between ii) and iv) p=0.229; and between iii) and iv) p=0.138. CONCLUSION: This is the first investigation where two modes of CV test, VA, and AA, for bleed-positive and bleed-negative CRC patients were used as the endpoint. The AA reading of the CV test showed higher DA in bleed-positive than in bleed-negative CRC patients.

The Automatically Analyzed (AA) ColonView (CV) Quick Test for Fecal Occult Blood Shows Higher Diagnostic Accuracy in Detection of Colorectal Adenoma than Visually Analyzed Tests.

BACKGROUND/AIM: The present study compared the accuracy of visually analyzed (VA) and automatically analyzed (AA) ColonView (CV) quick test; a new-generation fecal immunochemical test (FIT) for hemoglobin (Hb) and hemoglobin/haptoglobin (Hb/Hp) (Biohit Oyj, Helsinki, Finland) in subjects participating in colorectal neoplasia (CRN) detection in Brazil. A traditional guaiac-based fecal occult blood test (gFOBT) test (HemoccultSENSA) was used as a reference. PATIENTS AND METHODS: A cohort of 509 colonoscopy-referral patients were asked to collect three consecutive fecal samples, to be analyzed by both CV and SENSA. RESULTS: In ROC analysis for the AA reading, the optimal cut-off value for CV Hb was ≥8.0912 and that for CV Hb/Hp was ≥1.8983. With these cut-offs, the sensitivity (Se), specificity (Sp), and efficiency of CV AA in detecting colorectal adenoma (CRA) were: 64.2%/78.6%, 53.4%/35.3%, and 58.6%/56.5%, for Hb and Hb/Hp, respectively. In the HSROC analysis, the AUC values for i) VA and ii) AA modes were as follows: i) AUC=0.551 (95%CI=0.500-0.602), ii) AUC=0.606 (95%CI=0.550-0.662). The difference between these AUC values was statistically significant (p=0.0160). CONCLUSION: The present study confirms the previous results on the applicability of the ColonView quick test in CRN screening. Of the two optional reading modes, the AA reading showed significantly better diagnostic accuracy as compared to the VA reading (or SENSA), in detecting the CRA endpoint in colonoscopy-referral patients.