Primary resistance to icotinib in a patient with lung adenocarcinoma harboring EGFR L858R and Q787k mutations

Approximately 50% of patients with non-small-cell lung cancer (NSCLC) harbor epidermal growth factor receptor (EGFR) mutation in Asia, and the administration of EGFR-tyrosine kinase inhibitors (TKIs) has become the standard clinical therapeutic protocol [ [1] Shi Y. Au J.S. Thongprasert S. et al. A prospective, molecular epidemiology study of EGFR mutations in Asian patients with advanced non-small-cell lung cancer of adenocarcinoma histology (PIONEER). J. Thorac. Oncol. 2014; 9: 154-162 Abstract Full Text Full Text PDF PubMed Scopus (703) Google Scholar ]. Although most patients with EGFR-activating mutations responded well to EGFR-TKIs, primary resistance still occurred in approximately 5%–10% of the whole population [ [2] Zhong J. Li L. Wang Z. et al. Potential resistance mechanisms revealed by targeted sequencing from lung adenocarcinoma patients with primary resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs). J. Thorac. Oncol. 2017; 12: 1766-1778 Abstract Full Text Full Text PDF PubMed Scopus (27) Google Scholar ]. Here we report a female patient with lung adenocarcinoma harboring EGFR L858R and Q787k mutations who exerted primary resistance to icotinib.