Abstract
Although there has been significant advancement in the identification and management of colorectal cancer (CRC) in recent years, there is still room for improvement in the current standard treatment regimen. One area of concern is the lack of reliable tumor markers to predict treatment efficacy and guide tailored care. Due to its dynamic, effective, and non-invasive benefits over tissue biopsy, the detection of minimal or molecular residual lesions (MRD) based on circulating tumor DNA (ctDNA) is beneficial to the clinical development of drugs for patients with CRC after radical treatment, as well as for continuous monitoring of tumor recurrence and malignancy molecular gene evolution. The detection of ctDNA can currently be used to guide individual postoperative auxiliary treatment decisions (upgrade or downgrade treatment) in CRC, stratify the risk of clinical recurrence more precisely, and predict the risk of recurrence in advance of imaging examination, according to a large number of observational or prospective clinical studies. With increasing clarity comes the possibility of selecting a regimen of treatment based on postoperative ctDNA, which also improves the accuracy of clinical recurrence risk assessment for CRC. Therefore, it is anticipated that the identification of ctDNA would alter the current framework for dealing with CRC and lead to individualized, stratified precision therapy; however, additional confirmation will require subsequent high-quality, prospective, large-scale randomized controlled studies. This article will provide an overview of the definition and clinical significance of MRD, the primary indications and technological challenges for MRD detection, along with the advancement in clinical research about ctDNA detection following radical resection of the CRC.