[Efficacy of chemotherapy after EGFR-TKIs resistance in 191 patients with Unknow EGFR gene mutation in advanced lung adenocarcinoma].

BACKGROUND AND OBJECTIVE: Subsequent chemotherapy were needed in patients with advanced pulmonary adenocarcinoma experiencing disease progression after epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) treatment. The study is to explore factors potentially influencing efficacy of subsequent chemotherapy.

METHODS: One hundred and ninety-one patients with advanced lung adenocarcinoma, who were resistant from EGFR-TKIs and then received subsequent chemotherapy, were identified. Data of patient's characteristics, responses to chemotherapy and survival time were analyzed retrospectively.

RESULTS: The overall response rate of the pemetrexed-based chemotherapy (9.3%) was higher than non-pemetrexed-based regimen (1.1%), P=0.011. Furthermore, the response in the second-line was more obvisous [objective response rate (ORR) 14.3% vs 3.7%, P=0.041]. The patients who achieved response of partial response (PR) showed longer progression-free survival (PFS) than those who achieved non-PR (PFS 10.1 months and 2.3 months, P=0.012). The patients treated with platinum-based chemotherapy had longer PFS and OS than those with non-platinum-based chemotherapy, therefore platinum-based regimen was independent prognosis factors for PFS and OS (PFS: RR=0.634, 95%CI: 0.466-0.832, P=0.004; OS: RR=0.666, 95%CI: 0.460-0.960, P=0.030), especially the pateients who were aquired EGFR-TKIs resistance and who got drmatic progression from EGFR-TKIs treatment might got more benefits from platinum-based chemotherapy. However there was no significant difference in ORR, PFS or OS between patients with TKIs primary resistance and acquired resistance, or between dramtic progression and gradual/local progression.

CONCLUSION: The patients with advanced lung adenocarcinoma might get benefits from pemetrexed-based or platinum-based chemotherapy after they were EGFR-TKIs resistace.