Hepatic arterial embolization and chemoembolization for imatinib-resistant gastrointestinal stromal tumors

Objectives: We evaluated the efficacy of embolotherapy including hepatic arterial embolization and chemoembolization in patients with imatinib-resistant gastrointestinal stromal tumors with progressive liver metastases. Methods: Medical records and computed tomography images of patients with imatinib-resistant gastrointestinal stromal tumor with progressive liver metastases who underwent embolotherapy from January 2002 through January 2007 were retrospectively reviewed. Response was assessed by Response Evaluation Criteria in Solid Tumors and modified CT response criteria that assessed tumor density changes. Progression-free survival in the liver and overall survival rates were calculated from the date of the initial embolotherapy session using the Kaplan-Meier method. Correlations between disease status or treatment variables and survival were tested in univariate and multivariate analyses using the log-rank test, and the Cox proportional hazards model, respectively. Results: Fourteen patients with gastrointestinal stromal tumor who had been treated with imatinib for 7 to 61 months underwent 26 sessions of embolotherapy. Radiologic response could be evaluated in 13 patients. On the basis of response evaluation criteria in solid tumors, 1 patient demonstrated a partial response and the remaining 12 patients demonstrated stable disease. On the basis of the modified CT response criteria, 7 patients demonstrated a partial response and 6 patients demonstrated stable disease. Progression-free survival rates in the liver were 78.7%, 31.4%, and 31.4% at 6 months, 1, and 3 years, respectively; the median progression-free survival time was 7.0 months. Overall survival rates were 78.6%, 45.8%, and 45.8% at 6 month, 1 year, and 3 year, respectively; the median overall survival time was 9.7 months. Patients who had progressive extrahepatic metastases at the time of treatment and those who received only 1 embolotherapy treatment had shorter OS than did patients with liver-only progression and those who received 2 or more treatment sessions, respectively. Conclusions: Hepatic arterial embolization and chemoembolization induced radiologic response or disease stabilization in most patients with imatinib-resistant gastrointestinal stromal tumor with progressive liver metastases. Patients with progressive extrahepatic metastases or those who are not amenable to more than 1 embolotherapy sessions, however, did not demonstrate an appreciable survival benefit following embolotherapy.