Impact of surgery on advanced gastrointestinal stromal tumors (GIST) in the imatinib era.

BACKGROUND: The role for surgery in patients with "unresectable" gastrointestinal stromal tumors (GIST) treated with imatinib is still not defined. The objective of this retrospective study was to evaluate the feasibility and benefit of this secondary surgery.
METHODS: Progression-free survival (PFS) in a group of patients who underwent secondary surgery was compared to that of patients treated exclusively with imatinib.
RESULTS: Of 180 patients with unresectable GIST treated with Imatinib, 22 (12%) underwent secondary surgery, following which one patient achieved a complete radiological response, 19 achieved a partial response (PR), in one patient the disease was stable, and in one patient there was reactivation of local occlusive disease after an initial PR. No patient with overall progression was to undergo surgery. At the beginning of imatinib therapy, five patients with metastases underwent emergency surgery [hemorrhage (n = 3) due to rupture of large necrotic masses], which ultimately resulted in three of the five patients dying postoperatively. A macroscopically complete resection was achieved in all primary tumors (5/5) and in ten of the 17 metastases. Pathological analysis revealed two complete response (CR) and 17 PR, and no treatment effect was evidenced in three patients. Two-year overall survival after surgery was 62%. The median PFS calculated from the initiation of imatinib therapy was 18.7 months for all operated patients and 23.4 months after planned surgery.
CONCLUSION: Primary tumors that become amenable to surgery with prior imatinib therapy, evolving necrosis and localized progression (to avoid life-threatening complications) could benefit from this secondary surgery. For the majority of other residual lesions, the potential benefit of secondary surgery should be evaluated in randomized studies in the future since PFS is similar to that reported among non-operated patients.