Author of

• 10743

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  P1.10 - Poster Session 1 - Chemotherapy (ID 204)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Medical Oncology
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/28/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 10795

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    P1.10-052 - Influence of the epidermal growth factor receptor gene mutation subtypes to the prognosis of the patients with non-small cell lung cancer (ID 3165)

    09:30 - 09:30  |  Author(s): K. Hirai
    • Abstract

    Background
    Thirty to forty percent of East Asian patients with non-small cell lung cancer (NSCLC) have epidermal growth factor receptor (EGFR) gene mutations, which are recognized as predictive factors of the response to EGFR tyrosine kinase inhibitors (EGFR-TKIs). The most common mutations are the in-frame deletion in exon 19 and a substitution of lysine for arginine mutation at amino acid position 858 (L858R) in exon 21. It has been reported that subtype of EGFR gene mutation affects the efficacy of EGFR-TKIs in Caucasian patients with NSCLC. The deletion in exon 19 was reported to be an independent predictive factor of longer progression free survival (PFS); however, it was not a predictive factor of overall survival (OS).

    Methods
    We reviewed the records of patients with NSCLC referred to our hospital from May 2007 to May 2013, to clarify the influence of EGFR gene mutation subtype to clinical features.

    Results
    We found 128 patients with EGFR mutation, involving 124 cases of adenocarcinoma. According to the UICC-TNM ver.7, number of the patients with stage I/II disease was 59, while patients with stage III/IV was 69. We selected 60 patients with non-resectable disease (stage IIIB and IV) for the detailed analysis. The median age of the 60 patients was 74 year-old (range, 41-83). There were 39 female patients, and 39 light or never-smokers. The number of the patients with deletion mutation in exon 19 was 32 (the ratio of E746-A750 del was 78%); while the number of those with mutation in exon 21 was 24 (L858R was 96%). EGFR-TKIs were administered to 52 (86.7%) patients (erlotinib, gefitinib, and both was given in 20, 20, and 12 patients, respectively), including 35 patients without prior chemotherapy. The median duration of observation was 557 days. Any relationship between OS and clinical factor (gender, smoking history, and EGFR gene mutation subtypes) was not seen. In the patients treated with EGFR-TKIs, there was no significant difference in median OS regarding the administered drug (300 days with erlotinib or 285 days with gefitinib). In the patients with the exon 21 mutation, erlotinib-treated group had longer survival time than that of gefitinib group (200 days vs 150 days in median OS, p = 0.079). This observation was not confirmed in the patients with the exon 19 mutation.

    Conclusion
    Our retrospective analysis showed no difference of OS under subtype of EGFR gene mutation; however, the efficacy of EGFR-TKIs may differ in subtypes of EGFR gene mutation.