Do patients with initially resected metastatic GIST benefit from 'adjuvant' imatinib (IM) treatment? Results of the prospective BFR14 French Sarcoma Group randomized phase III trial

9501 Background: Metastatic GIST patients (pts) without residual disease after surgical resection are considered as at very high risk of relapse (VHR) but the impact of imatinib (IM) treatment while in CR (‘adjuvant‘ IM) is still debated. Preliminary data for such patients included in the modified BFR14 (continuation vs discontinuation of IM after 3 years of treatment) are presented. Methods: Characteristics and outcome of patients with VHR at inclusion and treated with IM were analyzed. Pts initially allocated to the discontinuation of BFR14 after 1 year of IM were excluded from this analysis. Results: Out of 265 pts with advanced disease, 96 metastatic, completely resected, GIST pts (52 males and 44 females) were included in the trial with a median age of 61 years (range 28 to 87). Primary resected sites were gastric and small bowel in 40% and 42% of cases respectively. Site of dissemination in synchronously resected (R0/R1 resections) metastases was liver only (45%), peritoneum only (15%) and liver plu...