Abstract
INTRODUCTION: Metastatic and recurrent gastrointestinal stromal tumors (GISTs) present challenging clinical management. Imatinib is the standard first-line therapy, improving survival and reducing tumor burden in the neoadjuvant use, facilitating surgical intervention. This systematic review and meta-analysis assessed the efficacy of neoadjuvant imatinib in metastatic/recurrent GISTs, highlighting its potential to enhance surgical outcomes and overall patient management. METHODS: A systematic search was conducted in PubMed, Embase and Scopus (end-of-search: February 13, 2025) for records on neoadjuvant imatinib therapy in recurrent/metastatic GISTs. Pooled proportions and 95% confidence intervals were calculated with common-effect and random-effects models. Subgroup and meta-regression analysis were performed, addressing heterogeneity and examining any potential association between the factors that varied and the outcomes reported. The present meta-analysis was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. RESULTS: The search identified 957 articles, and 14 were analyzed. The meta-analysis of proportions indicated that 2-year and 5-year PFS were 76% (95% CI 58-88%) and 43% (95% CI 17-74%), respectively, while 2-year and 5-year OS were 84% (95% CI 78-89%) and 60% (95% CI 51-68%), respectively. The pooled R0 resection rate was 82% (95% CI 64-92%), associated positively with that of radiological partial response (PR) (β = 3.92, p < 0.001). Further meta-regression analysis yielded no significant association with preoperative imatinib duration. CONCLUSION: The present meta-analysis of trials and studies on metastatic or recurrent GISTs highlights key insights into post-surgery patient outcomes following neoadjuvant treatment with imatinib. Pooled effect estimates revealed promising 2-year and 5-year PFS rates of 76% and 43%, respectively, and 2-year and 5-year OS rates of 84% and 60%, respectively. Furthermore, the high pooled R0 resection rate of 82% emphasizes a substantial surgical efficacy in this population, while it was significantly correlated with successful R0 resections in patients with favorable outcomes.