Efficacy Of Gefitinib And EGFR Mutations On West Chinese Patients With Advanced Refractory Non-Small Cell Lung Cancer

【Background】Lung cancer is one of the malignant tumors with highest morbidity andmortality in China, 75% ~ 80% of which are non-small cell lung cancer (NSCLC).Due to lack of effective early diagnostic methods, 60%~70% of NSCLC patientsare already at advanced stage when they are diagnosed. Therefore, it isimpossible to perform radical resection for them. The chemotherapy orradiotherapy is applied for relief with unsatisfactory efficacy.Targeted therapy is a new treatment for lung cancer and epidermal growthfactor receptor (EGFR) is one of the primary targets. Gefitinib, the first agentwhich received FDA approval, is designed for the EGFR target for the treatmentof NSCLC. Gefitinib is a epidermal growth factor receptor (EGFR) inhibitorand is able to selectively block the EGFR signal transduction system. Thespecific activating mutations within the tyrosine kinase domain of EGFR have been identified as the molecular correlation of the dramatic responses to gefitinibon American . Yet few researches on west Chinese patients have been done. TheEGFR mutation, efficacy of gefitinib, survival time and potential influencingfactors were analyzed on west Chinese patients with advanced refractory NSCLCin this research.【PurposePurposes】The aim of this study is to evaluate the efficacy of gefitinib and EGFRmutations on the west Chinese patients with advanced refractory non-small celllung cancer.【Contents】One hundred and twenty one west Chinese patients who failed previouschemotherapy regimens with stageⅢB-Ⅳnon-small cell lung cancer received250mg/day gefitinib until disease progression or serious adverse reactions werefound. Mutations in the exons 18, 19, 21 of EGFR gene in primary tumors fromthe patients were searched before the treatment. Regular examinations andfollow-up visits were performed from the beginning of gefitinib treatment. Thecorrelations among efficacy, EGFR mutation and median survival time wereanalyzed.【Results】Among 115 evaluable Chinese western patients, 13 cases had completeresponse, 25cases had a partial response, 38 cases had stable disease, 39 caseshad progression of disease. The disease control rate was 66.3%. The1- and 2-yearcumulative survival rate was 59.7% and 26.9%. The median survival time was 16 months. Thirty-one patients with EGFR mutations were detected in 115 patients.The patients possessed EGFR mutations conferred susceptibility to gefitinib.Non-smoking female patients possessed better efficacy and longer mediansurvival time. No differences of factors among age, number of previouschemotherapy cycles and tumor staging in clinical outcome and survival termwere found.【ConclusionConclusions】Gefitinib monotherapy has definite efficacy on the west Chinesenon-smoking female patients with non-small cell lung cancer. High EGFRmutation rate and long survival time was found in west Chinese female lungadenocarcinoma patients.