A Comprehensive Analysis of Integrating Guaiac Fecal Occult Blood Test and Fecal Immunochemical Test for Colorectal Cancer Screening

Abstract

Background: Colorectal cancer (CRC) accounts for a significant share of cancer mortality globally, highlighting the critical importance of early detection through screening. Non-invasive methods such as fecal immunochemical tests (FIT) and guaiac-based fecal occult blood tests (gFOBT) are established to identify occult blood in stool specimens. Integrating FIT and gFOBT may improve diagnostic accuracy for CRC screening. Methods: A comprehensive literature review was conducted across PubMed/MEDLINE, Scopus, and Google Scholar, utilizing targeted keywords to identify relevant human studies. The primary aim was to explore whether combining FIT and gFOBT could yield improved diagnostic performance and screening efficacy for CRC and adenomatous lesions. Findings: A review of the literature revealed no studies explicitly assessing the integration of FIT and gFOBT compared to each test individually or to colonoscopy. Nevertheless, several investigations assessing both modalities in comparable cohorts indicated that, despite the lower overall sensitivity of gFOBT, positive results from gFOBT can emerge even when FIT results are negative. The proposed integration of these tests holds the potential to enhance sensitivity, specificity, and cost-effectiveness in CRC screening. Conclusion: Integrating FIT and gFOBT offers a promising approach to enhancing the effectiveness of CRC screening through complementary detection mechanisms, better management of intermittent bleeding patterns, and improved detection of proximal lesions. While this hypothesis presents several challenges and limitations, preliminary validation could be performed using existing data from previous studies. Further research is necessary to evaluate this integrative approach rigorously. © 2025, Isfahan University of Medical Sciences(IUMS). All rights reserved.