Author of

• 18374

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  P3.02b - Poster Session with Presenters Present (ID 494)

  • Event: WCLC 2016
  • Type: Poster Presenters Present
  • Track: Advanced NSCLC
  • Presentations: 1
  • Moderators:
  • Coordinates: 12/07/2016, 14:30 - 15:45, Hall B (Poster Area)

  • 18452

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    P3.02b-078 - Non-Small Cell Lung Cancer with De Novo EGFR T790M Mutation: Clinical Features of 22 Cases (ID 4981)

    14:30 - 14:30  |  Author(s): J.S. Ahn
    • Abstract

    Background:
    This study aimed to evaluate the clinical features and outcomes in patients with non-small cell lung cancer (NSCLC) with de novo epidermal growth factor receptor (EGFR) T790M mutation.
    
    Methods:
    Specimens of 6,923 NSCLC patients, from March 2009 to May 2016, tested for EGFR mutation were analyzed. EGFR mutation was performed using DNA sequencing or PNA clamp method. The clinical characteristics and the clinical outcome to chemotherapy and EGFR tyrosine kinase inhibitors (TKIs) were reviewed.
    
    Results:
    Of the 6,923 NSCLC patients, 1687 (24.4%) had activating EGFR mutations. Among them, 22 patients were found to have de novo EGFR T790M mutation, accounting for 1.3% of all the EGFR mutant cases. All but one had de novo T790M mutation without any activating EGFR mutation. Details of the 22 patients harboring the EGFR T790M mutation are listed in Table 1. The response rate to chemotherapy was 12.5% (best response; 1 PR, 4 SD and 3 PD) and the median time to progression (TTP) was 3.0 months. The response rate to EGFR TKIs treatment was 8.3% (best response; 1 PR, 3 SD and 8 PD), and the median TTP was 2.7 months. Three patients were treated with third generation EGFR TKIs (osimertinib or ASP 8237) and all achieved partial response (TTP; 33.3, 13.6 and 3.5 months, respectively).
    
    Conclusion:
    De novo EGFR T790M mutation is a rare event even in EGFR mutant NSCLC and associated with unfavorable clinical outcome to chemotherapy and EGFR TKIs.