Primary resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in patients with non-small-cell lung cancer harboring TKI-sensitive EGFR mutations: an exploratory study

Ann Oncol. 2013 Aug;24(8):2080-7. doi: 10.1093/annonc/mdt127. Epub 2013 Apr 4.

Abstract

Background: The mechanism of primary resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in EGFR-mutant non-small-cell lung cancer (NSCLC) has not been clearly understood.

Patients and methods: Eleven patients exhibiting primary resistance (disease progression <3 months) were identified among 197 consecutive NSCLC patients with TKI-sensitive EGFR mutations who received EGFR TKIs at Seoul National University Hospital. Treatment-naïve tumors were examined for concurrent genetic alterations using fluorescence in situ hybridization and targeted deep sequencing of cancer-related genes. Deletion polymorphism of Bcl-2-interacting mediator of cell death (BIM) gene was examined to validate its predictive role for TKI outcome.

Results: The median progression-free survival (PFS) for patients receiving EGFR TKIs was 11.9 months, and the response rate 78.8%. Among the 11 patients exhibiting primary resistance, a de novo T790M mutation was identified in one patient, and two exhibited mesenchymal-epithelial transition amplification and anaplastic lymphoma kinase fusion. Targeted deep sequencing identified no recurrent, coexistent drivers of NSCLC. Survival analysis revealed that patients with recurrent disease after surgery had a longer PFS than those with initial stage IV disease. However, BIM deletion polymorphism, line of treatment, EGFR genotype, and smoking were not predictive of PFS for EGFR TKIs.

Conclusions: We identified coexistent genetic alterations of cancer-related genes that could explain primary resistance in a small proportion of patients. Our result suggests that the mechanism of primary resistance might be heterogeneous.

Keywords: epidermal growth factor receptor mutation; erlotinib; gefitinib; primary resistance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Apoptosis Regulatory Proteins / genetics
  • Base Sequence
  • Bcl-2-Like Protein 11
  • Carcinoma, Non-Small-Cell Lung / drug therapy*
  • Carcinoma, Non-Small-Cell Lung / genetics
  • Cell Transdifferentiation / genetics
  • Disease-Free Survival
  • Drug Resistance, Neoplasm
  • ErbB Receptors / antagonists & inhibitors*
  • ErbB Receptors / genetics*
  • Erlotinib Hydrochloride
  • Female
  • Gefitinib
  • Genotype
  • Humans
  • Lung Neoplasms / drug therapy*
  • Lung Neoplasms / genetics
  • Male
  • Membrane Proteins / genetics
  • Middle Aged
  • Mutation
  • Protein Kinase Inhibitors / therapeutic use*
  • Proto-Oncogene Proteins / genetics
  • Proto-Oncogene Proteins c-bcl-2 / genetics
  • Quinazolines / therapeutic use
  • Sequence Analysis, DNA
  • Sequence Deletion / genetics

Substances

  • Apoptosis Regulatory Proteins
  • BCL2L11 protein, human
  • Bcl-2-Like Protein 11
  • Membrane Proteins
  • Protein Kinase Inhibitors
  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-bcl-2
  • Quinazolines
  • Erlotinib Hydrochloride
  • EGFR protein, human
  • ErbB Receptors
  • Gefitinib