Blood test may spot hidden GIST recurrence before scans do

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: I. Inclusion Criteria for the Prospective Study on Postoperative Minimal Residual Disease (MRD) Surveillance in High-Risk Gastrointestinal Stromal Tumors (GIST) Without Adjuvant Therapy 1. Aged 18-75 years. 2. Patients suspected of having high-risk GIST based on preoperative imaging, or patients with biopsy-confirmed high-risk GIST who have not received preoperative neoadjuvant therapy. 3. Treatment-naive patients who have not previously received radiotherapy, chemotherapy, surgery, or any other anticancer treatment. 4. Adequate hepatic, renal, and other major organ function, with the patient considered medically fit to undergo surgery. 5. Postoperative pathological confirmation of gastrointestinal stromal tumor. 6. Tumor genotyping demonstrating a genotype associated with primary resistance to imatinib, such as a PDGFRA D842V mutation, or a clear decision by the patient to decline postoperative adjuvant imatinib therapy. 7. A definite contraindication to imatinib or another targeted therapy. 8. Patients who underwent R0 resection of the primary tumor, completed long-term postoperative adjuvant therapy, and discontinued treatment at least 3 months previously. 9. The patient and family members are able to understand the study protocol; the patient voluntarily agrees to participate and provides written informed consent. II. Inclusion Criteria for the Development of a Genomics-Based Recurrence Risk Prediction Model for High-Risk GIST and Identification of the Optimal Target Population for MRD Surveillance a. The inclusion criteria are identical to those of the prospective study on postoperative MRD surveillance in high-risk GIST without adjuvant therapy. Exclusion Criteria: I. Exclusion Criteria for the Prospective Study on Postoperative Minimal Residual Disease (MRD) Surveillance in High-Risk Gastrointestinal Stromal Tumors (GIST) Without Adjuvant Therapy 1. A history of another malignant tumor or the presence of another concurrent malignancy. 2. Emergency surgery required because of intestinal obstruction, perforation, bleeding, or a similar condition. 3. Pregnancy or breastfeeding. 4. A history of severe psychiatric illness. 5. Any contraindication to surgical treatment. 6. Failure to achieve R0 resection. 7. Low- or intermediate-risk disease according to postoperative pathological risk stratification. 8. Presence of distant metastasis. 9. Any other condition that, in the investigator's judgment, renders the patient unsuitable for enrollment. II. Exclusion Criteria for the Development of a Genomics-Based Recurrence Risk Prediction Model for High-Risk GIST and Identification of the Optimal Target Population for MRD Surveillance a. The exclusion criteria are identical to those of the prospective study on postoperative MRD surveillance in high-risk GIST without adjuvant therapy.