GRIm Score Predicts Curative Conversion Surgery in Unresectable Gastric Cancer

Background/Aim: Conversion surgery can prolong survival in initially unresectable gastric cancer when curative (R0) resection is achieved; however, pre-treatment predictors of R0 conversion remain limited. We investigated whether the Gustave Roussy Immune (GRIm) score predicts R0 resection and survival in patients considered for conversion surgery. Patients and Methods: We retrospectively analyzed 57 patients with unresectable advanced gastric cancer treated with systemic chemotherapy from January 2019 to July 2025. Patients were classified as achieving conversion (AC; conversion surgery with R0 resection) or non-conversion (NC). The GRIm score (albumin, lactate dehydrogenase, and neutrophil-to-lymphocyte ratio) and clinicopathological variables were evaluated as predictors of R0 resection using univariate and multivariate logistic regression. Overall survival (OS) was assessed using the Kaplan-Meier method. Results: Ten patients (17.5%) achieved R0 resection. The AC group had lower GRIm scores and a more favorable Yoshida classification than the NC group, and intestinal-type histology was more frequent in the AC group. In multivariate analysis, a low GRIm score (0-1) and Yoshida classification C1-2 were independently associated with R0 resection. OS was significantly longer in patients with low GRIm scores than in those with high scores. Conclusion: The GRIm score is an accessible pre-treatment biomarker associated with successful R0 conversion surgery and improved survival in unresectable gastric cancer and may complement the Yoshida classification in candidate selection.