Triage Process at Endoscopy With ColonView Fecal Immunochemical Test (FIT) Will Enhance Diagnostic Accuracy (DA) of Colorectal Cancer Screening

Abstract

Background/aim: This study assessed the diagnostic accuracy (DA) of the predictive features of colorectal cancer (CRC, predictCRC), triage process (triage), and ColonView (CV) fecal immunochemical test (FIT) in a CRC screening setting. The diagnostic score models (DMs) including predictCRC with triage and CV test were also calculated.

Patients and methods: The study cohort of 544 patients included 58 CRC patients and 486 non-CRC patients who submitted three consecutive fecal samples for analysis, by two fecal occult blood (FOB) assays (CV FIT test, HemoccultSENSA test). Hierarchical multilevel logistic models were used to test the DA (for CRC) of each item of predictCRC (with triage I and II) and DMs, visualized as hierarchical summary receiving operating characteristic (HSROC) curves.

Results: The DA of the predictCRC location of neoplasm (Loc), triage I, and triage II showed 49%, 41%, and 93% sensitivity (Se), and 70%, 99.5%, and 88% specificity (Sp), respectively. The PPV+ of triage I (92%) was higher than that of Loc (22%) or triage II test (45%). In the conventional receiver operating characteristic (ROC) analysis, the area under the curve (AUC) values for the different DMs ranged from 0.880 (for DM without triage I and II), whereas the highest AUC value of 0.960 was reached for DM with triage I and II included in the formula. In the HSROC analysis, the AUC values were as follows: i) with all predictCRCs, AUC=0.717 and ii) with DMs, AUC=0.937. In the roccomp analysis, the difference in AUC values between i) and ii) was statistically significant (p<0.0001).

Conclusion: In the detection of CRC, the DA of the new DMs with triage was far superior to that of DMs without triage. This is the first study to report evidence of improved DA in the detection of CRC using DMs including predictCRC with triage and CV FIT test.

Keywords: Colorectal cancer; FIT; clinical features; colonoscopy; diagnosis; multivariate analysis; triage.