Lih-Chyun Chang1, Chor-Kuan Lim2, Lih-Yu Chang3, Kuan-Yu Chen4, Jin-Yuan Shih5, Chong-Jen Yu5. 1. Department of Internal Medicine, National Taiwan University Hospital Yun-Lin Branch, No.579, Sec. 2, Yunlin Road, Douliu City, Yunlin County, 640, Taiwan. 2. Division of Pulmonary Medicine, Department of Internal Medicine, Far Eastern Memorial Hospital, No.21, Sec. 2, Nanya South Road, Banciao District, New Taipei City, 220, Taiwan. 3. Department of Internal Medicine, National Taiwan University Hospital Hsin-Chu Branch, No.25, Lane 442, Sec. 1, Jingguo Road, Hsinchu City, 300, Taiwan. 4. Division of Pulmonary Medicine, Department of Internal Medicine, National Taiwan University Hospital and College of Medicine, National Taiwan University, No. 7, Chung-Shan South Road, Taipei, 100, Taiwan. Electronic address: tuff.chen@msa.hinet.net. 5. Division of Pulmonary Medicine, Department of Internal Medicine, National Taiwan University Hospital and College of Medicine, National Taiwan University, No. 7, Chung-Shan South Road, Taipei, 100, Taiwan.
Abstract
INTRODUCTION: Non-small cell lung cancer (NSCLC) harbouring EGFR exon 19 deletions or L858R mutation usually respond to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), whereas T790M mutation and exon 20 insertion are frequently resistant to EGFR-TKIs. EGFR mutations other than those above are seldom investigated. METHODS: In this multicentre, retrospective study, we enrolled NSCLC patients with non-resistant uncommon EGFR mutations, which were defined as mutations other than L858R, exon 19 deletions, exon 20 insertions and T790M. The mutation patterns, clinical data and treatment outcomes were analysed. Patients were classified as gefitinib/erlotinib and afatinib groups according to the EGFR-TKIs received as the first-line therapy. RESULTS: A total of 177 patients were identified (177/1983, 8.9%). Sixty-six patients had more than one EGFR mutation, including those coexisting with exon 19 deletion or L858R mutation. In treatment-naïve patients with advanced stages (n = 72), the objective response rate was 35.8% for gefitinib/erlotinib group and 60.6% for afatinib group (p = 0.036). In multivariate analysis, no significant differences were found between gefitinib/erlotinib and afatinib groups in median progression-free survival (PFS) and overall survival (OS). Brain metastasis at diagnosis was associated with a shorter PFS (hazard ratio [HR] = 2.49, 95% confidence interval [CI] = 1.29-4.83) and OS (HR = 3.22, 95% CI = 1.41-7.35). CONCLUSIONS: For patients with NSCLC harbouring non-resistant uncommon EGFR mutations, afatinib use as the first-line therapy may provide a better treatment response but no survival benefit, as compared with gefitinib or erlotinib. Brain metastasis at diagnosis is associated with a poor prognosis.
INTRODUCTION:Non-small cell lung cancer (NSCLC) harbouring EGFR exon 19 deletions or L858R mutation usually respond to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), whereas T790M mutation and exon 20 insertion are frequently resistant to EGFR-TKIs. EGFR mutations other than those above are seldom investigated. METHODS: In this multicentre, retrospective study, we enrolled NSCLCpatients with non-resistant uncommon EGFR mutations, which were defined as mutations other than L858R, exon 19 deletions, exon 20 insertions and T790M. The mutation patterns, clinical data and treatment outcomes were analysed. Patients were classified as gefitinib/erlotinib and afatinib groups according to the EGFR-TKIs received as the first-line therapy. RESULTS: A total of 177 patients were identified (177/1983, 8.9%). Sixty-six patients had more than one EGFR mutation, including those coexisting with exon 19 deletion or L858R mutation. In treatment-naïve patients with advanced stages (n = 72), the objective response rate was 35.8% for gefitinib/erlotinib group and 60.6% for afatinib group (p = 0.036). In multivariate analysis, no significant differences were found between gefitinib/erlotinib and afatinib groups in median progression-free survival (PFS) and overall survival (OS). Brain metastasis at diagnosis was associated with a shorter PFS (hazard ratio [HR] = 2.49, 95% confidence interval [CI] = 1.29-4.83) and OS (HR = 3.22, 95% CI = 1.41-7.35). CONCLUSIONS: For patients with NSCLC harbouring non-resistant uncommon EGFR mutations, afatinib use as the first-line therapy may provide a better treatment response but no survival benefit, as compared with gefitinib or erlotinib. Brain metastasis at diagnosis is associated with a poor prognosis.