Abstract | PURPOSE: PATIENTS AND METHODS: We examined the relationship between kinase genotype and treatment outcome for 428 patients enrolled on the North American phase III study SWOG S0033/CALGB 150105 and treated with either 400 mg or 800 mg daily doses of imatinib. RESULTS: The presence of KIT exon 11-mutant genotype (n = 283) correlated with improved treatment outcome when compared with KIT exon 9-mutant (n = 32) and wild-type (WT; n = 67) genotypes for objective response (complete response [CR]/partial response [PR], 71.7% v 44.4% [P = .007]; and 44.6% [P = .0002], respectively); time to tumor progression ( TTP; median 24.7 months v 16.7 and 12.8 months, respectively); and overall survival (OS; median 60.0 months v 38.4 and 49.0 months, respectively). The survival outcomes for patients with exon 9-mutant, exon 11-mutant or WT GIST were not affected by imatinib dose. However, there was evidence of improved response rates for patients with exon 9-mutant tumors treated with imatinib 800 mg versus 400 mg (CR/PR, 67% v 17%; P = .02). Patients who had CD117-negative GIST had similar TTP but inferior OS compared with patients who had CD117-positive disease, which suggests that patients who have CD117-negative GIST may benefit from imatinib treatment. In addition, we identified novel but rare mutations of the KIT extracellular domain (exons 8 and 9). CONCLUSION: We confirmed the favorable impact of KIT exon 11 genotype when compared with KIT exon 9 and wild-type genotype for patients with advanced GIST who are treated with imatinib.
|
Authors | Michael C Heinrich, Kouros Owzar, Christopher L Corless, Donna Hollis, Ernest C Borden, Christopher D M Fletcher, Christopher W Ryan, Margaret von Mehren, Charles D Blanke, Cathryn Rankin, Robert S Benjamin, Vivien H Bramwell, George D Demetri, Monica M Bertagnolli, Jonathan A Fletcher |
Journal | Journal of clinical oncology : official journal of the American Society of Clinical Oncology
(J Clin Oncol)
Vol. 26
Issue 33
Pg. 5360-7
(Nov 20 2008)
ISSN: 1527-7755 [Electronic] United States |
PMID | 18955451
(Publication Type: Clinical Trial, Phase III, Journal Article, Multicenter Study, Randomized Controlled Trial, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S.)
|
Chemical References |
- Benzamides
- Piperazines
- Pyrimidines
- Imatinib Mesylate
- Proto-Oncogene Proteins c-kit
- Receptor, Platelet-Derived Growth Factor alpha
|
Topics |
- Benzamides
- Disease-Free Survival
- Gastrointestinal Stromal Tumors
(drug therapy, genetics, mortality, pathology)
- Genotype
- Humans
- Imatinib Mesylate
- Mutation
- Piperazines
(therapeutic use)
- Proto-Oncogene Proteins c-kit
(genetics)
- Pyrimidines
(therapeutic use)
- Receptor, Platelet-Derived Growth Factor alpha
(genetics)
- Survival Rate
|