Efficacy of imatinib dose escalation in Chinese gastrointestinal stromal tumor patients

AIM:To investigate the efficacy and safety of imatinib dose escalation in Chinese patients with advanced gastrointestinal stromal tumor (GIST).METHODS:Advanced GIST patients previously failing 400 mg imatinib treatment were enrolled in this study.Patients received imatinib with dose escalation to 600 mg/d,and further dose escalation to 800 mg/d if imatinib 600 mg/d failed.Progression-free survival,overall survival,clinical efficacy,c-kit/PDGFRA genotype and safety were evaluated.RESULTS:52 patients were enrolled in this study.For the 47 evaluable patients receiving imatinib (600 mg/d),the disease control rate was 40.4%,and the median progression-free survival for all patients was 17 wk (95% CI:3.9-30.1).The median overall survival after dose escalation was 81 wk (95% CI:36.2-125.8).Adverse events,mainly edema,fatigue,granulocytopenia and skin rash were tolerable.However,further dose escalation (800 mg/d) in 14 cases was ineffective,with disease progression and severe adverse events.Among 30 cases examined for gene mutations,patients with exon 9 mutations experienced a better progression-free survival of 47 wk.CONCLUSION:Imatinib dose escalation to 600 mg/d is more appropriate for Chinese patients and may achieve further survival benefit.