Mutations in the epidermal growth factor receptor gene in non-small cell lung cancer: Impact on treatment beyond gefitinib and erlotinib.

Epidermal growth factor receptor (EGFR)-activating mutations in non-small cell lung cancer (NSCLC) are molecular targets for treatment with gefitinib and erlotinib, often resulting in improved response and prolonged progression-free survival. Resistance to these drugs, which develops during treatment, is a problem of paramount importance. Several mechanisms of "acquired resistance" have been discovered and treatments for this specific entity are on the horizon.