Post-imatinib surgery in advanced/metastatic GIST: is it worthwhile in all patients?

Background: Surgical indication for metastatic gastrointestinal stromal tumor (GIST) treated with imatinib is not yet established. Materials and methods: We analyzed 80 patients who underwent surgery for metastatic GIST after imatinib therapy from July 2002 to October 2007. Patients were divided into those with surgery at best clinical response (group A, n = 49) and those with surgery at focal progression (group B, n = 31). Primary end points were progression-free survival (PFS) and disease-specific survival (DSS). Results: Two-year postoperative PFS was 64.4% in group A and 9.7% in group B (P < 0.01). In group A, median PFS was not reached; in group B, it was 8 months. Median DSS from the time of imatinib onset was not reached in either group. Five-year DSS was 82.9% in group A and 67.6% in group B (P < 0.01). Multivariate analysis confirmed a significantly shorter PFS and DSS in group B. Surgical morbidity occurred in 13 patients (16.3%). Conclusions: Surgery for focal progressive lesions could be considered as part of the second-line/third-line armamentarium in selected cases. Surgery of residual disease upon best clinical response seems associated with survival benefit compared with historical controls in similar patient collectives treated with imatinib alone. However, evidence from prospective randomized trials is needed to make definite recommendations.