A Prospective Study on Predicting Recurrence Risk of Postoperative High-risk GISTs in NED State Based on MRD Detection Via Liquid Biopsy

The goal of this single-center, prospective, observational cohort study is to learn whether tumor-informed minimal residual disease (MRD) testing in blood can predict recurrence in 66 patients with high-risk gastrointestinal stromal tumor (GIST) who are not currently receiving postoperative adjuvant therapy. The main questions it aims to answer are: Can changes in MRD during follow-up predict tumor recurrence? How closely do MRD results agree with contrast-enhanced computed tomography (CT) findings, and can MRD identify recurrence earlier than CT? Can tumor genomic features, changes in MRD, and clinicopathological features be combined to develop a model for predicting recurrence risk? Participants will have their surgical tumor tissue analyzed, provide blood samples for MRD testing, and undergo regular clinical follow-up and contrast-enhanced CT examinations for 3 years. Participants may choose to receive and discuss their MRD results. This study will not assign or change treatment based on MRD results. Recurrence and treatment decisions will remain based on routine clinical assessment, primarily contrast-enhanced CT and multidisciplinary review.