The present study investigated the characteristic of the divergent efficacy of epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) Gefitinib in treating non small-cell lung cancer (NSCLC) and discussed the strategy. The divergent efficacy of gefitinib was analyzed in 4 NSCLC patients at Beijing Military Area General Hospital between 2006 and 2010. The divergence phenomenon may occur in gefitinib-treated NSCLC patients with bone or brain metastases. One patient with primary lung disease under control still benefited from continuing Gefitinib therapy after disease progression in metastatic bone lesion. The divergence of efficacy is a common phenomenon in Gefitinib-treated NSCLC patients. The evaluation criteria available for anti-cancer therapies may not be completely suitable for molecular targeted therapies. The underlying mechanism deserves further research to formulate the efficacy evaluation criteria and therapeutic strategy for the molecular targeted therapy.

Key words: Non small-cell lung cancer, tyrosine kinase inhibitor, divergence phenomenon, gefitinib, targeted therapy.