Role of operative therapy in treatment of metastatic gastrointestinal stromal tumors

Background: Operative resection of metastatic gastrointestinal stromal tumors (GIST) is controversial. Current treatment strategies rely on the response to tyrosine kinase inhibitors (TKIs), with resultant individualization of operative intervention. We investigated the role of operative therapy in patients with metastatic GIST. Methods: This retrospective cohort study included all consecutive patients treated for metastatic and/or recurrent GIST from January 2002 to June 2011. The patients were stratified by the use of operative therapy and disease response to TKI therapy. Kaplan-Meier survival analyses with log-rank comparisons tested the effects of operative therapy and the response to TKIs on survival. Results: Of the 438 patients treated for GIST during the study period, 87 (median age 61 y, interquartile range 50-71; 55% male) had metastatic GIST (84% metastatic, 3% recurrent, and 13% metastatic and recurrent). Of these patients, 54 (62%) underwent operative exploration. Subtotal resection for palliative debulking (R2 resection) were performed in 19 patients; 32 patients underwent R0 resection. Operative intervention was associated with improved overall survival (OS) compared with systemic therapy alone (1 y OS, 98% versus 80% and 5-y OS, 65% versus 11%, respectively; P < 0.001). A TKI was used before resection in 32 patients. The disease response was partial in 13 patients, stable in 10, and progressive in 9. The 1- and 5-y OS and progression-free survival were strongly associated with the preoperative response to TKI and an R0 resection (all P ≤ 0.002). Conclusions: Among patients with metastatic GIST, preoperative response to TKI therapy and margin-negative resection were strongly associated with improved progression-free and OS.