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)

  • 18485

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    P3.02b-111 - Can We Avoid Using Chemotherapy in Managing Acquired Resistance of EGFR-Mutated NSCLC? (ID 4851)

    14:30 - 14:30  |  Author(s): T.-. Prempree
    • Abstract

    Background:
    Since the discovery of Non small cell lung cancer with activating mutation of EGFR, most studies have proved that EGFR tyrosine kinase inhibitor to be the treatment of choice with high degree of success and with median response duration of one year. Acquired resistance of EGFR - TKI is inevitable due to various mechanisms including T790M mutation of EGFR , exon 20 . Managing acquired resistance of EGFR mutated NSCLC requires special consideration to obtain success particularly to avoid using chemotherapy.
    
    Methods:
    From our own series of advanced NSCLC ,42 patients were indentified as having EGFR mutation for which TKI was used along with other targeted medicine such as Bevacizumab. Of 42 patients treated with multitargeted medicines, 21 cases had proven T790M mutatiom from re-biopsy while the rest may have T790M or other activating mutations without proven. Those who developed resistance to TKI must have tumor markers rising and tumor site progression and finally have muliple organs progression. Treatment of resisitance included: 1.) Change to second generation of TKI such as Afatinib 2.) Use Anti-PI3K or mTOR-inhibitor such as Torisel 20 mg IV weekly
    
    Results:
    21 cases of T790M activating mutation came from: 1.) 22 cases of classical exon 19 deletion had 5 cases of T790M 2.) 7 cases of exon 21 point mutation had 6 cases of T790M 3.) 13 cases of various exon 19 mutation had 10 cases of T790M All 21 cases of T790M servived the resistance treatment at least 1 year after the discovery T790M.
    
    Conclusion:
    Our results appeared to show; 1.) Multiple targeted medicines treatment appreared to reduce the resistance to TKI 2.) Those harbored classical exon 19 deletion appreared to have less TKI resisitance 3.) Those harbored exon 21 EGFR mutation and non-classical exon 19 mutation appreared to have TKI resistance more (average 1 year) 4).We could avoid using chemotherapy in those who developed TKI resistance at least in a short period of time and it will require further study