Noninvasive diagnosis of colorectal adenoma: The emerging potential of blood-based biomarkers

Colorectal cancer (CRC) is the third most commonly diagnosed cancer and the second leading cause of cancer-related death globally. Most CRCs arise from colorectal adenomas (CRAs), particularly advanced adenomas, which are recognized as critical precancerous lesions. Early detection and intervention at the adenoma stage are essential for alleviating the global disease burden of CRC. However, conventional screening methods such as colonoscopy are invasive and have poor compliance, underscoring the urgent need for efficient, noninvasive diagnostic alternatives. Blood-based biomarkers have gained substantial attention because of their accessibility, reproducibility, and potential for early detection. Advances in multiomics technologies including proteomics, metabolomics, transcriptomics, and epigenomics have led to the identification of numerous plasma- and serum-derived biomarkers. These include noncoding RNAs (e.g., microRNAs, circular RNAs, PIWI-interacting RNAs), DNA methylation signatures, disease-specific proteins, and metabolic profiles. Moreover, emerging platforms such as liquid biopsy, extracellular vesicle profiling, and machine learning further expand the landscape of early CRA detection. The integration of multiomics data holds promise for substantially increasing the sensitivity and specificity of early adenoma detection, offering a transformative framework for precise CRC screening and risk stratification.