Neoadjuvant imatinib in patients with locally advanced GIST in the prospective BFR14 trial
10551 Background: The role of surgery in the management of patients with advanced gastrointestinal stromal tumors (GIST) in the era of imatinib mesylate (IM) remains unknown. We sought to assess the outcome of patients with locally advanced primary GIST tumors without metastases treated with IM in the neoadjuvant setting within the prospective BFR14 phase III trial. Methods: The data base of the BFR14 trial was searched for patients with locally advanced disease and no metastases. Patients with recurrent disease were excluded. Results: Twenty five patients (9 females, 16 males) met these criteria. Twenty patients were PS 0 or 1, primary tumor sites were: small intestine (n=7), peritoneum (n=7), rectum (n=4), stomach (n=4), esophagus (n=2), and pelvis (n=1). Nine of the 25 patients underwent surgical resection of the primary tumor after a median of 7.3 (range 3.4–12.1) months of treatment with IM. There was a significant improvement in progression-free survival (PFS) for patient who underwent surgical resection versus those who did not: median PFS: 28.7 month vs 12.9 months respectively (p=0.0463) this benefit did not however translate into a significant benefit in overall survival (OS), although the trend favoured the resected group: median OS median not reached vs 29.4 months (p=0.0677). Conclusions: Surgery may increase progression-free survival in patients with locally advanced GIST who become resectable following treatment with IM. [Table: see text]