C-KIT mutations were closely associated with the response to Imatinib in Chinese advanced gastrointestinal stromal tumor patients

Med Oncol. 2012 Dec;29(5):3039-45. doi: 10.1007/s12032-012-0308-7. Epub 2012 Jul 20.

Abstract

To investigate the correlation between C-KIT/PDGFRα mutations and Imatinib response or survival in Chinese advanced gastrointestinal stromal tumor (GIST) patients. Clinical data and paraffin-embedded tumor specimens were collected from 158 advanced GIST patients receiving first-line Imatinib. Mutation analyses of C-KIT gene (Exons 9, 11, 13, and 17) and PDGFRα gene (exons 12 and 18) were performed by PCR amplification and Sanger sequencing. A total of 135 patients harboring C-KIT mutations (exon 11 mutation: 108; exon 9 mutation: 23; exon 13 mutation: 2; exon 17 mutation: 2) and one patients carrying PDGFRα mutation (exon 18) were found in this study. Twenty-two patients (13.9 %) with neither C-KIT nor PDGFRα mutations were named as wild type. The response rate (64.7 vs. 36.4 %, P = 0.000) and median progression-free survival (28 vs. 8 months, P = 0.000) of mutant patients (n = 136) were significantly higher than those of wild-type patients (n = 22). Moreover, the response rate and median progression-free survival in patients with exon 11 mutations (n = 108), exon 9 mutations (n = 23), and wild-type patients (n = 22) were 68.5, 47.8, and 36.4 % (P = 0.001), and 31 months, 13 months, and 8 months (P = 0.000), respectively. No significant differences of response rate or median progression-free survival were seen in patients with exon 11 deletion mutations, point mutations, and mixed-type mutations. C-KIT mutations were closely associated with Imatinib response and progression-free survival of Chinese advanced GIST patients. Other predictive markers for Imatinib would be further investigated.

MeSH terms

  • Adult
  • Aged
  • Antineoplastic Agents / therapeutic use*
  • Asian People
  • Benzamides / therapeutic use*
  • Biomarkers, Tumor / genetics
  • DNA Mutational Analysis
  • Disease-Free Survival
  • Drug Resistance, Neoplasm / genetics*
  • Female
  • Gastrointestinal Stromal Tumors / drug therapy
  • Gastrointestinal Stromal Tumors / genetics*
  • Gastrointestinal Stromal Tumors / mortality
  • Humans
  • Imatinib Mesylate
  • Kaplan-Meier Estimate
  • Male
  • Middle Aged
  • Mutation
  • Piperazines / therapeutic use*
  • Proportional Hazards Models
  • Proto-Oncogene Proteins c-kit / genetics*
  • Pyrimidines / therapeutic use*
  • Reverse Transcriptase Polymerase Chain Reaction

Substances

  • Antineoplastic Agents
  • Benzamides
  • Biomarkers, Tumor
  • Piperazines
  • Pyrimidines
  • Imatinib Mesylate
  • Proto-Oncogene Proteins c-kit