A novel prognostic system for locally advanced gastrointestinal stromal tumors after neoadjuvant imatinib therapy based on the metro-ticket paradigm: a retrospective dual-center study

The source explains the development and validation of the ypT-TRG staging system, designed to improve the prognosis assessment for patients with locally advanced gastrointestinal stromal tumors (LA-GIST) treated with preoperative imatinib. This new system was created to overcome limitations in the existing NIH criteria, which struggle to accurately assess prognostic factors like the mitotic index after neoadjuvant therapy. By integrating the tumor regression grade (TRG) and ypT staging, researchers constructed a more robust staging tool using a retrospective analysis of 200 patients. The study found that the ypT-TRG system provided superior prognostic stratification and discriminatory ability compared to the NIH criteria. Crucially, the system offers practical clinical utility by aiding in the selection of patients for minimally invasive surgery and optimizing postoperative imatinib treatment strategies.