Non-invasive colorectal cancer screening: emerging tools and clinical evidence

The fecal immunochemical test (FIT) is a widely used non-invasive screening method for colorectal cancer (CRC) in many countries, valued for its simplicity, affordability, and reasonable sensitivity. Typically recommended on an annual or biennial basis, the FIT is effective in reducing CRC incidence and mortality by facilitating early detection. Stool DNA tests, including multitarget DNA tests and DNA methylation assays, demonstrate higher sensitivity than FIT for CRC and advanced adenomas, although they have slightly lower specificity and higher cost. These tests are generally performed at longer intervals, such as every 3 years, and are useful alternatives for individuals who are unwilling or unable to undergo a colonoscopy. Emerging non-invasive CRC screening tools, such as liquid biopsy, microRNA, microbiome tests, and urine-based tests, are being developed to improve patient compliance and test convenience. In particular, liquid biopsy offers a minimally invasive option that may be more acceptable to populations hesitant to undergo stool-based tests. Furthermore, the integration of machine learning with metagenomic sequencing data has shown promise in distinguishing patients with CRC from healthy individuals. As CRC screening evolves, these novel approaches may enable the development of more personalized, accessible, and effective screening strategies, ultimately improving adherence and reducing CRC-related mortality.