Clinical characteristics of lung adenocarcinoma bearing acquired resistance of EGFR-TKI

ZHANG Ping; WU Xiaonan; NIE Xin; AI Bin; LI Lin; CHENG Gang

doi:10.3969/j.issn.1009-0460.2017.05.010

Abstract：Objective To investigate the clinical characteristics of acquired resistance of epidermal growth factor receptor (EGFR) sensitive mutation in patients with advanced lung adenocarcinoma treated with first-line EGFR-tyrosine kinase inhibitor(EGFR-TKI)therapy.Methods A total of 193 patients with advanced lung adenocarcinoma bearing EGFR sensitive mutation were enrolled from January 2011 to December 2015, and 120 patients of them were given the first-line EGFR-TKI therapy.The relationship of short-term efficacy, as well as EGFR mutation types and locations of tumor progression was analyzed.Results No complete remission (CR) was observed in 120 patients receiving the first-line EGFR-TKI treatment.Eighty patients (66.7%) achieved partial remission (PR) and the median progression-free survival (PFS) was 12.1 months.Thirty-six patients (30.0%) achieved stable disease (SD) and the median PFS was 6.1 months.The difference of PFS between them had statistical significance (P<0.05).Among patients achieved PR and SD, the exon 19 deletions was found in 64 cases (55.2%) and the median PFS was 11.0 months.The mutation of L858R occurred in 52 cases (44.8%) and the median PFS was 8.6 months, the differences between PFS also had statistical significance (P<0.05).Fifty cases (43.1%) with acquired resistance only had progresses in original lesions, and 66 patients (56.9%) were found new lesion metastases.At the time of disease progression, lung progression accounted for 37.9%, followed by brain metastases accounted for 26.7%.Clincial efficacy (PR/SD) and EGFR mutation (exon 19 deletions/L858R mutations) were not related to location of tumor progression and original/new lesions(P>0.05).Conclusion Lung is the most common locations of tumor progression after acquired resistance to EGFR-TKI in patients with EGFR mutation, followed by brain metastases.The location of tumor progression and clinical efficacy, as well as EGFR mutation genotypes are not exactly related.