Recurrent, metastatic, and locally advanced gastrointestinal stromal tumors (GISTs) can be treated successfully with imatinib mesylate. Surgery for residual disease has been suggested for nonrefractory metastatic GISTs to reduce the probability of resistant recurrent clones, although no randomized Phase III trial has been performed to answer the question about its benefit. We carried out an analysis of the outcome of patients with recurrent unresectable locally advanced or metastatic imatinib-sensitive priamary GIST in 14 institutions in Spain. We compared two cohorts: treated or not treated with surgery after partial response or stabilization by imatinib.
Data were obtained from the online GIST registry of the Spanish Group for Research in Sarcomas. Selected patients were then divided into two groups: group A, treated initially only with imatinib, and group B, treated additionally with metastasectomy. Baseline characteristics between groups were compared, and univariate and multivariate analysis for progression-free survival and overall survival (OS) were performed.
Analysis was undertaken in 171 patients considered nonrefractory to imatinib. The median follow-up time was 56.6 months. Focusing on OS, the Eastern Cooperative Oncology Group performance status different than 0, extent of disease limited to one metastatic organ, and comparison between groups A or B achieved statistical difference in the multivariate analysis. Median survival was 59.9 months in group A and 87.6 months in group B.
Based in its benefit in OS, our study supports surgery of metastatic disease in GIST patients who respond to imatinib therapy.