Epidermal growth factor receptor tyrosine kinase inhibitors in the treatment of NSCLC.

Improvements in our understanding of the molecular biology of cancer have shifted management of lung cancer toward molecular-guided, individualized treatment. Development of epidermal growth factor receptor tyrosine kinase inhibitors, erlotinib and gefitinib, represent the best example of this approach. Erlotinib was tested as second/third line treatment in unselected population of patients and demonstrated a statistically significant prolongation of overall survival, while gefitinib was shown to be non-inferior to docetaxel as second line treatment. The discovery of EGFR activating mutations facilitated the selection of patients most likely to benefit from erlotinib/gefitinib. These drugs in patients with EGFR activating mutations offer an increased progression free survival and significantly higher response rates compared to chemotherapy. The purpose of this paper is to present the relevant clinical data, describe the predictive markers available for TKIs treatment in NSCLC, and describe the mechanisms associated with resistance to treatment with these agents.