title: Imatinib Mesylate for Patients with Recurrent or Metastatic Gastrointestinal Stromal Tumors Expressing KIT: A Decade Experience from Taiwan.
abstract: OBJECTIVE
  Our preliminary report of imatinib mesylate (IM) in gastrointestinal stromal tumor (GIST) patients detailed a high response rate; however, the long-term result is still unknown. We conducted an analysis of Taiwan advanced inoperable/metastatic GIST patients treated on IM regarding survival, pattern of failure, potential prognostic factors, and mutational status.
  
  
  METHODS
  From 2001 to 2010, patients with pathologically proven advanced inoperable/metastatic GIST receiving IM were enrolled onto this study. Data on KIT mutational status, measurable tumor size, and other potential prognostic factors were prospectively collected. Patients were followed up for a median of 33.6 months.
  
  
  RESULTS
  There were 171 patients (106 men and 65 women) with response rate, and their clinical benefit for IM was 57.3% and 87.1%, respectively. Median progression-free survival (PFS) and overall survival (OS) for these 171 patients are 37.6 and 71.0 months, respectively. Of 171 patients, 120 (70.2%) remained on long-term IM use. Poor performance status, tumor larger than 11.5 cm, primary resistance, and the presence of an exon 9 mutation were independently associated with unfavorable PFS. Regarding OS, poor performance status, primary resistance, and tumor larger than 11.5 cm were three independently unfavorable predictors.
  
  
  CONCLUSIONS
  The median PFS and OS of 171 GIST patients are 37.6 and 71.0 months, respectively. Poor performance status, tumor size larger than 11.5 cm, primary resistance, and an exon 9 mutation were independently associated with unfavorable PFS. Regarding OS, poor performance status, primary resistance, and tumor size larger than 11.5 cm were three independent unfavorable predictors.
authors.affiliation: GIST Team, Department of Surgery, Chang Gung Memorial Hospital, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Chun-Nan
authors.initials: CN
authors.lastname: Yeh
authors.forename: Yen-Yang
authors.initials: YY
authors.lastname: Chen
authors.forename: Jeng-Hwei
authors.initials: JH
authors.lastname: Tseng
authors.forename: Jen-Shi
authors.initials: JS
authors.lastname: Chen
authors.forename: Tsung-Wen
authors.initials: TW
authors.lastname: Chen
authors.forename: Chun-Yi
authors.initials: CY
authors.lastname: Tsai
authors.forename: Chi-Tung
authors.initials: CT
authors.lastname: Cheng
authors.forename: Yi-Yin
authors.initials: YY
authors.lastname: Jan
authors.forename: Miin-Fu
authors.initials: MF
authors.lastname: Chen