Objective: To evaluate the efficacy and influencing factors of imatinib in patients with advanced gastrointestinal stromal tumor(GIST).
Methods: From April 2004 to January 2010, clinicopathological data of 73 adult patients with advanced GIST treated with imatinib at the First Affiliated Hospital of Sun Yat-sen University were retrospectively analyzed. The treatment outcomes and associated factors were investigated.
Results: Treatment outcomes included complete response in 1(1.4%) patients, partial response in 53(72.6%), stable disease in 14(19.2%), and primary resistant in 5(6.8%). All the patients had routine followed up, the length of which ranged from 12 to 76 (median 32) months. The median progression-free survival was 45.0 months(95% confidence interval, 34.2-55.8). The progression-free survival(PFS) rate was 87.7% in 1 year, 63.6% in 3 year, and 39.6% in 5 years. On multivariate analysis, both mutation status and patient performance were independent factors influencing the efficacy of imatinib treatment(both P<0.01). PFS was significantly better in patients with c-kit exon 11 mutations than those with exon 9 mutations, and better in lower ECOG scales than in higher ones.
Conclusion: Imatinib is effective in treating patients with advanced GIST, c-kit exon 9 mutations and poor performance status predict an adverse survival benefit of imatinib therapy.