Objective： To investigate the efficacy and safety of gefitinib as maintenance therapy for advanced non-small cell lung cancer （NSCLC） patients who obtained disease control （DC） after first-line chemotherapy in Chinese population. Methods： Chinese patients with advanced NSCLC treated with standard chemotherapy and obtained DC were assigned to receive gefitinib as maintenance treatment. The primary end point was overall survival time （OS）, the second end point was disease control rate （DCR） and progression-free survival time （PFS）. DCR included complete response （CR） plus partial response （PR） and plus stable disease （SD）. The impact of epidermal growth factor receptor （EGFR） mutation status on the treatment as exploratory point was also evaluated by denaturing high-performance liquid chromatography （DHPLC）. Results： Among 75 enrolled patients, the overall response rate was 37% and the DCR （CR ＋ PR ＋SD） was 66%. The median PFS and OS were 17.13 months and 26.13 months respectively, with 1- and 2-year survival rates 89.3% and 34.7%. Patients harboring somatic EGFR mutations obtained a prolonged median PFS and OS compared with EGFR wide type （25.1 vs. 13.0 months, P=0.019 and 33.37 vs. 25.57 months, P=0.014, respectively）. In COX regression model, only EGFR mutation status was the independently factor influencing both PFS and OS （P=0.029 and 0.017, respectively）, however, rash status was the predictor in terms of PFS （P=0.027）. Conclusion： Gefitinib produced encouraging survival when delivered as maintenance therapy in Chinese patients obtaining DC after first-line chemotherapy, especially for patients carrying somatic EGFR mutations. EGFR mutation is an independently predictive factor of survival.
Lu YangZhi-jie WangTong-tong AnHua BaiJun ZhaoJian-chun DuanPing-ping LiMei-na WuHong SunLi LiangJie Wang
Background The genotype of epidermal growth factor receptor （EGFR） is associated with tyrosine kinase inhibitor and effectiveness of therapy, but its role in cytotoxic chemotherapy is still unknown. Previous studies indicated that certain EGFR mutations were associated with response and progression free survival following platinum based chemotherapy. Our recent studies have identified that EGFR genotypes in the tumour tissues were not associated with response to the first-line chemotherapy in Chinese patients with advanced non-small cell lung cancer （NSCLC）. In this study, we investigated associations of EGFR genotypes from plasma of patients with advanced NSCLC and response to first-line chemotherapy and prognosis. Methods We enrolled 145 advanced NSCLC patients who had received first-line chemotherapy in our department. We examined plasma EGFR genotypes for these patients and associations of EGFR mutations with response to chemotherapy and clinical outcomes. Results There were 54 patients with known EGFR mutations and 91 cases of wild types. No significant difference was detected in the response rate to first-line chemotherapy between mutation carriers and wild-type patients （37.0% vs. 31.9%）. The median survival time and 1-, 2-year survival rates were higher in mutation carriers than wild-types （24 months vs. 18 months, 85.7% vs. 65.7% and 43.7% vs. 25.9%, P=0.047）. Clinical stage （Ⅳvs. Ⅲb）, response to the first-line chemotherapy （partial vs. no） and EGFR genotype were independent prognostic factors. Conclusion Plasma EGFR mutations in the Chinese patients with advanced NSCLC is not a predictor for the response to first-line chemotherapy, but an independent prognostic factor indicating longer survival.
