Abstract: Erlotinib, a kind of epidermal growth factor receptor tyrosine kinase inhibitors ( EGFR-TKIs), has been effectively used in the treatment of non-small cell lung cancer (NSCLC). Although it prolongs patients survival time, erlotinib is limited to be further applied for its resistance. It has been proved that threonine to  methionine mutations in codon 790 (T790M), Kirsten rat sarcoma viral oncogene homolog (KRAS) mutation and the amplification of met oncogene play important roles in the drug resistance. Based on the different molecular mechanisms of resistance, multiple clinical trials of the second generation TKIs, retreatment of chemotherapy or erlotinib and subsequent treatment according to failure modes have been developed.

Key words: Carcinoma, non-small-cell lung, Drug resistance, neoplasm, Antineoplastic agents