Abstract:Colorectal cancer (CRC) ranks among the leading causes of cancer incidence and mortality worldwide. Microsatellite instability (MSI) is a key molecular biomarker with important implications for prognosis and immunotherapy selection. Although conventional detection methods such as immunohistochemistry, PCR, and next-generation sequencing have been standardized, they remain limited by high costs, technical complexity, and inconsistent results. In recent years, artificial intelligence (AI) has shown great potential in MSI detection by integrating multimodal data that includes histopathological images, genomic information, and medical imaging to achieve accurate prediction and enable a data-driven paradigm in oncology. This review summarizes the latest advances in AI-based multimodal modeling for MSI detection in CRC, compares different methodological approaches and their translational challenges, and discusses future directions such as multimodal integration, model generalizability, and interpretability enhancement, providing new insights for precision medicine.