Advances in non-invasive screening tests for colorectal cancer and adenoma
摘要
<p indent="0mm">Colorectal cancer (CRC) ranks as the fourth leading cause of cancer-related deaths in China. Early detection of CRC and its precursor, colorectal adenoma (CRA), is crucial to reduce morbidity and mortality rates. However, the current gold standard for CRC diagnosis, colonoscopy, is invasive, requires cumbersome preoperative bowel preparation, and is expensive, leading to poor patient compliance. Therefore, the development of noninvasive diagnostic methods is urgently needed to improve patient adherence. This review provides a comprehensive overview of the advancements in noninvasive diagnostic tests for CRC and CRA. Various modalities, including nucleic acid markers, circulating tumor cells (CTCs), circulating free DNA (cfDNA), protein markers, gut microbiome analysis, gut metabolomics, and imaging techniques, are discussed, along with their underlying principles and diagnostic accuracies. The advantages and limitations of each diagnostic modality are also examined, and future trends in the development of noninvasive biomarkers for CRC and CRA diagnosis are explored. Noninvasive diagnostic markers for CRC and CRA are predominantly sourced from blood and fecal samples. Nucleic acid markers derived from exfoliated tumor cells can be detected in both blood and fecal samples. Blood-based markers, such as cfDNA and CTCs, are also utilized. Fecal protein markers originate from host cells or bleeding, including hemoglobin, transferrin, calreticulin, and M2-PK. Additional fecal markers encompass metagenomic DNA markers, bacterial markers, and bacterial metabolites. Stool-based testing has proven to be a valuable CRC screening approach, with the fecal immunochemical test (FIT) being the most widely used noninvasive method. However, FIT sensitivity for CRC detection varies across different studies and is particularly inadequate for adenoma detection. Recent investigations have demonstrated that fecal bacterial biomarkers exhibit superior diagnostic sensitivity