Imatinib efficacy by tumor genotype in Korean patients with advanced gastrointestinal stromal tumors (GIST): The Korean GIST Study Group (KGSG) study
2011; Taylor & Francis; Volume: 51; Issue: 4 Linguagem: Inglês
10.3109/0284186x.2011.636753
ISSN1651-226X
AutoresHye Jin Kang, Min‐Hee Ryu, Kyoung‐Mee Kim, Young Soo Park, Jene Choi, Baek‐Yeol Ryoo, Woo Ho Kim, Seock‐Ah Im, Yung‐Jue Bang, Se Hoon Park, Jae-Hyuk Lee, Ik Joo Chung, Han‐Ik Bae, Jong Gwang Kim, Kyung Hee Lee, Hong Song, Hyuk‐Chan Kwon, Jin Ho Baek, Dong Bok Shin, Kyoung Eun Lee, Yoon‐Koo Kang,
Tópico(s)Gastric Cancer Management and Outcomes
ResumoPurpose. To assess the efficacy of imatinib for different tumor genotypes in Korean patients with advanced gastrointestinal stromal tumors (GIST). Material and methods. Clinical data were collected from 370 consecutive patients with locally advanced unresectable, metastatic, or recurrent GIST treated with imatinib 400 mg/day between August 2001 and December 2007 at 20 Korean institutions. Tumor genotypes were determined for 290 patients by direct DNA sequencing of KIT exons 9, 11, 13, and 17, and PDGFRA exons 12, 14, and 18. Results. Of 290 patients assessed for genotype, 261 (90.0%) had mutations in KIT: 222 (76.6%) in exon 11, 35 (12.1%) in exon 9 and two each (0.7%) for exons 13 and 17. Four patients (1.4%) had mutations in the PDGFRA gene: one in exon 12, and three in exon 18. Twenty-five patients (8.6%) had no detectable mutations. The best responses of the 235 patients with measurable lesions were: 15 complete response (6.4%), 126 partial response (53.5%), 86 stable disease (36.6%), and eight progressive disease (3.4%). Patients with KIT exon 9 mutations, compared with patients with KIT exon 11 mutations, had a lower objective response rate (36.7% vs. 63.6%, p = 0.007) and a shorter progression-free survival (median 28.7 months vs. 49.4 months, p = 0.001). No statistical difference in overall survival was observed between these genotypes. Conclusion. This study confirms that imatinib efficacy is dependent on genotype in Korean GIST patients, consistent with results demonstrated by Western patients with GIST.
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