title: A prospective, multicenter, phase 2 study of imatinib mesylate in korean patients with metastatic or unresectable gastrointestinal stromal tumor.
abstract: OBJECTIVE
  This prospective, multicenter, phase 2 study evaluated the efficacy and safety of imatinib mesylate and assessed KIT and PDGFRA gene mutation status in Korean patients with gastrointestinal stromal tumors (GISTs).
  
  
  METHODS
  Forty-seven patients with pathologically proven KIT-positive metastatic or unresectable GISTs were accrued from eight institutions in Korea. Imatinib was administered orally at 400 mg once daily. In case of disease progression, the dose was escalated to 600 mg once daily, then 400 mg twice daily. KIT and PDGFRA mutations were analyzed in 29 of the 47 patients.
  
  
  RESULTS
  Imatinib produced partial responses in 30 patients (63.8%; 95% confidence interval, 50.1-77.6%) and stable disease in 13 patients (27.7%). The median time to response was 2.6 months (range, 1.0-6.2 months). With a median follow-up of 62 months (range, 32-67 months), 4-year progression-free survival and overall survival rates were 50 and 65%, respectively. The most common adverse events were anemia, neutropenia, edema, and skin rash (predominantly of grade 1-2). There were no treatment-related deaths. In the subset evaluated for mutational status, 24 patients (82.8%) had KIT exon 11 mutations and 1 (3.4%) had a KIT exon 9 mutation.
  
  
  CONCLUSIONS
  Imatinib is effective and safe in Korean patients with metastatic or unresectable GIST.
authors.affiliation: Department of Internal Medicine, Division of Oncology, Asan Medical Center, Songpa-Gu, Seoul, Korea.
authors.forename: Min-Hee
authors.initials: MH
authors.lastname: Ryu
authors.forename: Won Ki
authors.initials: WK
authors.lastname: Kang
authors.forename: Yung-Jue
authors.initials: YJ
authors.lastname: Bang
authors.forename: Kyung Hee
authors.initials: KH
authors.lastname: Lee
authors.forename: Dong Bok
authors.initials: DB
authors.lastname: Shin
authors.forename: Baek-Yeol
authors.initials: BY
authors.lastname: Ryoo
authors.forename: Jae Kyung
authors.initials: JK
authors.lastname: Roh
authors.forename: Jin-Hyoung
authors.initials: JH
authors.lastname: Kang
authors.forename: Hyoungnam
authors.initials: H
authors.lastname: Lee
authors.forename: Tae Won
authors.initials: TW
authors.lastname: Kim
authors.forename: Heung Moon
authors.initials: HM
authors.lastname: Chang
authors.forename: Joon Oh
authors.initials: JO
authors.lastname: Park
authors.forename: Young Suk
authors.initials: YS
authors.lastname: Park
authors.forename: Tae-You
authors.initials: TY
authors.lastname: Kim
authors.forename: Min Kyoung
authors.initials: MK
authors.lastname: Kim
authors.forename: Woon Kee
authors.initials: WK
authors.lastname: Lee
authors.forename: Hye Jin
authors.initials: HJ
authors.lastname: Kang
authors.forename: Yoon-Koo
authors.initials: YK
authors.lastname: Kang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001549:Benzamides; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D005838:Genotype; D006801:Humans; D000068877:Imatinib Mesylate; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010879:Piperazines / Q000627:therapeutic use*; D011110:Polymorphism, Genetic; D011379:Prognosis; D011446:Prospective Studies; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics / Q000378:metabolism; D011743:Pyrimidines / Q000627:therapeutic use*; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000235:genetics / Q000378:metabolism; D012074:Remission Induction; D012307:Risk Factors; D015996:Survival Rate; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D001549:Benzamides; D010879:Piperazines; D011743:Pyrimidines; D000068877:Imatinib Mesylate; D011505:Protein-Tyrosine Kinases; D019009:Proto-Oncogene Proteins c-kit; D020796:Receptor, Platelet-Derived Growth Factor alpha