Evaluating Performance of Combined Hemoglobin and Transferrin Detection in Fecal Immunochemical Testing for Colorectal Neoplasia

Background. Evidence-based screening strategies can substantially reduce colorectal cancer (CRC) mortality. While colonoscopy is the gold standard, its invasiveness renders it less preferable as an initial screening tool. A two-step approach using a non-invasive fecal immunochemical test (FIT) followed by a confirmatory colonoscopy is gaining favor. A novel FIT that simultaneously detects fecal hemoglobin (F-Hb) and fecal transferrin (F-Tf) demonstrates variable diagnostic performance. Aim. This study compared the diagnostic performance of four screening strategies using three FITs with different cutoffs for F-Hb and F-Tf to detect neoplastic lesions in patients with suspected CRC. Materials and Methods. We conducted a cross-sectional study involving suspected CRC patients aged ≥ 18 at Hasan Sadikin Hospital, Bandung, from March 2023 to August 2023. The study included 72 clinically suspected CRC patients who underwent colonoscopy. We compared four CRC screening strategies using FITs designated as FIT-I (F-Hb ≥ 10 ng/mL), FIT-II (F-Hb ≥ 50 ng/mL), FIT-IIIa (F-Hb ≥ ≥ 100 ng/mL or F-Tf ≥ 40 ng/mL), and FIT-IIIb (F-Hb ≥ 100 ng/mL and F-Tf ≥ 40 ng/mL). Results. The FIT-IIIb strategy, which requires positive results for both markers, yielded the highest diagnostic performance for detecting neoplastic lesions, with 60.0% sensitivity, 96.6% specificity, a 93.8% positive predictive value, and a 73.7% negative predictive value. Conclusion. A dual-marker FIT detecting both F-Hb and F-Tf is a promising and effective screening tool for CRC. Future research should explore its implementation in broader populations and potential impacts on screening guidelines.