• Tomoyuki Otsuka, Masahide Mori, Yukihiro Yano, Junji Uchida, Kazumi Nishino, Reiko Kaji, Akito Hata, Yoshihiro Hattori, Yoshiko Urata, Toshihiko Kaneda, Motoko Tachihara, Fumio Imamura, Nobuyuki Katakami, Shunichi Negoro, Satoshi Morita, and Soichiro Yokota.
• Department of Thoracic Oncology, National Hospital Organization Toneyama National Hospital, Toyonaka, Japan Department of Respiratory Medicine, Allergy, and Rheumatic Diseases, Osaka University Graduate School of Medicine, Suita, Japan.
• Anticancer Res. 2015 Jul 1; 35 (7): 3885-91.

AimNon-small cell lung cancer (NSCLC) with minor mutations in the epidermal growth factor receptor (EGFR) gene, except for the common 15 base-pair deletions in exon 19 and the L858R mutation in exon 21, is rare, and only few data exist on this patient population. The aim of the present study was to describe the clinical characteristics and to clarify the efficacy of EGFR-tyrosine kinase inhibitors (TKIs) in patients with NSCLC harboring minor mutations of the EGFR gene.Patients And MethodsThis was a multicenter, retrospective study that analyzed specimens from patients with NSCLC who had minor EGFR gene mutations and were treated with EGFR-TKIs between June 2002 and March 2012.ResultsOut of 56 patients with minor mutations of the EGFR gene, 44 were treated with either gefitinib or erlotinib. Mutation sites were G719X in exon 18 (n=35), L861Q in exon 21 (n=11), and G874S in exon 21 (n=1). Three patients had both the G719S and the L861Q mutation. The response rate to TKI treatment was 29.5%, and the disease control rate was 63.6%. The median progression-free survival (PFS) was 6.7 months [95% confidence interval (CI)=2.06-8.66 months]. The median PFS was 7.2 months (95% CI=4.23-12.3 months) in 32 patients who received first- or second-line treatment with EGFR-TKIs, whereas the median PFS was 1.57 months (95% CI=0.73-3.8 months) in 12 patients treated with EGFR-TKIs as a third-line or later treatment. In multivariate Cox analysis, erlotinib therapy was associated with a longer PFS than gefitinib (p=0.025).ConclusionPatients with NSCLC harboring minor mutations of the EGFR gene exhibited a modest response to EGFR-TKI treatment. Treatment with first-generation EGFR-TKIs, in particular erlotinib, may be considered a first- or second-line option for patients with NSCLC with minor EGFR mutations.Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

43 keywords...

hide…