Background and purpose: Non-small cell lung cancer (NSCLC) patients who have good curative effect on epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) will inevitably acquired drug resistance. It will effect the survival directly. In contrast

few studies have found that EGFR-TKI effectively acquired drug resistance in patients with clinical characteristics. We investigated clinical characteristics of NSCLC patients who experienced acquired drug resistance during gefitinib therapy. Methods: To review the treatment from the benefit of patients with non-small cell lung cancer. All of the data were obtained from Jan. 2007 to Jan. 2014 in Xinjiang tumor hospital. The treatment for failure of acquired drug resistance of clinical manifestations

time to progress (TTP) and post-progression survival (PPS) were retrospectively analyzed. Results: The total collection of 417 patients. Median TTP was 10.2 months (95%CI: 9.5-10.9). The TTP of women adenocarcinoma patients who didn’t smoke significantly extended. When acquired drug resistance happened

63.3% of patients appeared worse symptoms. The progress of the disease is as follows: 209 cases (58.4%) from the primary lesion

137 cases (38.3%) before the transfer

194 cases (54.2%) of new happened. Patients of epidermal growth factor receptor (EGFR) wild type had more tendencies of symptomatic deterioration and new central nervous system (CNS) transfer than patients of EGFR mutation type. Patients of exon 19 deletion and L858R mutations on the new transfer were different (41.4% vs 6.3%

P=0.02). PPS was 8.9 months (95%CI:7.4-10.4). Smoking history

performance status (PS) score

new CNS lesions and the subsequent chemotherapy isindependent factors of PPS. Conclusion: This study suggests that the clinical manifestations of acquired drug resistance according to EGFR mutation status and EGFR mutation genotype may be different. In addition

after the treatment of acquired drug resistance in patients with non-small cell lung cancer

the subsequent clinical benefit from chemotherapy are also associated with PPS.