Molecular Residual Disease Monitoring and Early Recurrence Prediction in Solid Tumors: Clinical Applications and Evidence

Recent advances in liquid biopsy technologies, particularly circulating tumor DNA (ctDNA) analysis, have enabled the sensitive and non-invasive detection of molecular residual disease (MRD) in solid tumors. This review summarizes the current clinical evidence and applications of MRD monitoring in solid cancers, focusing on colorectal cancer and non-small cell lung cancer (NSCLC). Tumor-informed and tumor-uninformed ctDNA assays are compared, highlighting their respective advantages and limitations. Landmark studies such as the DYNAMIC and GALAXY trials in colorectal cancer, and the TRACERx study in NSCLC, have demonstrated the prognostic value of ctDNAbased MRD detection for recurrence risk stratification and for guiding adjuvant therapy decisions. Ongoing research and standardization efforts are expected to further establish MRD assessment as an integral component of precision oncology.