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

  • 10746

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    P1.10-003 - Alteration of the E-cadherin/β-catenin complex predicts poor response to epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) treatment (ID 161)

    09:30 - 09:30  |  Author(s): Y.J. Kim
    • Abstract

    Background
    Epidermal growth factor receptor (EGFR) mutation alone may be insufficient to predict clinical outcomes in the response to EGFR-tyrosine kinase inhibitor (TKI) therapy. The secondary mutation T790M and MET amplification are mechanisms of acquired resistance to EGFR-TKI in approximately 50% of patients, but the remaining mechanisms are unknown.

    Methods
    Eight metastatic lesions and specimens from 41 non-small cell lung carcinoma (NSCLC) patients harbouring activating EGFR mutations who underwent surgical resection and EGFR-TKI therapy were available. Immunohistochemistry was used to evaluate E-cadherin, β-catenin, and PTEN. Chromogenic in situ hybridisation and silver-enhanced in situ hybridisation were used to evaluate EGFR and MET amplification.

    Results
    Patients with E-cadherin/β-catenin alteration showed a poor objective response rate (ORR) (p=0.005) and shorter overall survival (p=0.059). Additionally, β-catenin alteration was associated with a poor ORR (p=0.012). In the metastatic tumours, 3 cases (37.5%) showed the acquisition of altered E-cadherin/β-catenin and PTEN loss, and 2 cases (25.0%) demonstrated MET/EGFR amplification.

    Conclusion
    Altered E-cadherin/β-catenin expression in NSCLC harbouring EGFR mutations was associated with a poor response to EGFR-TKI. During metastatic progression, changes in E-cadherin/β-catenin were found. These results may suggest that E-cadherin/β-catenin alteration is related to poor TKI response and resistance.