OBJECTIVETo evaluate the efficacy and influencing factors of imatinib in patients with advanced gastrointestinal stromal tumor(GIST).

METHODSFrom 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.

RESULTSTreatment 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.

CONCLUSIONImatinib 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.