Prediction of Postoperative Treatment Efficacy and Recurrence Risk of High-risk GIST Based on Minimal Residual Disease Detected by Liquid Biopsy

Assessing MRD (Minimal Residual Disease) and predicting the postoperative adjuvant treatment efficacy and recurrence risk of tumor patients based on ctDNA (circulating tumor DNA) detected by liquid biopsy have been exploratorily studied and applied in many types of cancers. However, as for GISTs (gastrointestinal stromal tumors), the most common mesenchymal neoplasm of the gastrointestinal tract, they have less peripheral ctDNA fragments compared with those tumors of hematological or epithelial origins. Since there are also some limitations of previous detection technology and detection depth, prospective study for prediction of postoperative treatment efficacy and recurrence risk of high-risk GIST is lacking.

In this study, a prospective multi-center, single-arm observational study is conducted to collect operable patients with locally advanced GIST. According to results of preoperative imaging examinations or pathological biopsy, 45 high-risk GIST patients will be screened and enrolled. Next-Generation Sequencing (NGS) genetic testing platform (Burning Rock Oncoscreen Plus TM) is used to detect the baseline tumour tissues (detection depth 1000X) of these patients. And peripheral ctDNA (detection depth 30000X) of multiple pre/postoperative time points will be detected. The genetic profile and clinical information of each patient will be collected. Combining all the information, bioinformatics analysis will be carried out on the gene detection results of these patients at each time point, and the correlation between the postoperative recurrence time and the ctDNA positive rate/postoperative clearance rate of patients will be compared. The characteristics changes and dynamic changes of tumor release degree will also be analyzed. To explore the correlation between PFS/OS and MRD in high-risk GIST patients, we plan to analyze the relationship between dynamic changes in ctDNA mutation spectrum and postoperative adjuvant therapy efficacy, and to evaluate MRD-based genomic characteristics to guide further treatment.