Author of

• 10583

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  P1.06 - Poster Session 1 - Prognostic and Predictive Biomarkers (ID 161)

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

  • 10590

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    P1.06-007 - Relationship between 5FU related enzymes and EGFR mutation status in non-small cell lung cancer treated with S-1 adjuvant therapy (ID 890)

    09:30 - 16:30  |  Author(s): J. Arai
    • Abstract

    Background
    Anti-cancer effect of 5-fluorouracil (5FU) is affected by the expressions of 5FU related enzymes, such as dihydropyrimidine dehydrogenase (DPD) and thymidine synthase (TS) and orotate phosphoribosyltransferase (OPRT), in each tumor. On the other hand, anti-cancer effect of epidermal growth factor receptor tyrosine kinase (EGFR-TKI) is affected by EGFR mutation status in each tumor. In 2007, Suehisa and colleagues reported that adjuvant chemotherapy with uracil-tegafur, a fluorouracil prodrug, significantly prolonged survival rates among patients with EGFR wild-type adenocarcinoma but not among patients with EGFR mutant tumors. In this study, the correlation between 5FU related enzymes and EGFR mutation status was analyzed.

    Methods
    We analyzed 49 patients with primary NSCLC who were postoperatively treated with S-1, an oral fluorouracil anticancer prodrug composed of tegafur, CDHP, and potassium oxonate in the molar ratio 1:0.4:1. We then evaluated the relation between the EGFR mutation status, each of the 5FU related enzymes and various clinicopathological factors. In vitro, DPD mRNA and protein expression was investigated in various cell lines.

    Results
    Among the 49 cases (thirty adenocarcinoma (ADC), sixteen squamous cell carcinoma (SQCC), two adenosquamous carcinoma, and one carcinoid), EGFR mutation was observed only in ADC (12 patients; 24.5%). In immunohistochemical examination, 10 patients were DPD immune-positive (20.4%), 31 patients were OPRT immune-positive (63.3%), and 16 patients were TS immune-positive (32.7%). Three year disease free survival rate of single S-1 adjuvant therapy was 77.6%, and three year overall survival rate was 89.7%. DPD immune-positive cases were significantly correlated with EGFR mutation status (p = 0.003). In vitro, EGFR mutated cell lines showed high DPD mRNA and protein expression.Figure 1

    Conclusion
    High DPD expression was shown to be correlated with EGFR mutation in adenocarcinoma cells and tissues. This result indicates that 5FU might be effective for EGFR wild type tumors than mutant type tumor, and EGFR mutation status might be a potential poor predictive marker for treatment with 5FU drugs.