title: Prior EGFR tyrosine-kinase inhibitor therapy did not influence the efficacy of subsequent pemetrexed plus platinum in advanced chemonaïve patients with EGFR-mutant lung adenocarcinoma.
abstract: BACKGROUND
  Tumor cells before and after epidermal growth-factor receptor (EGFR) tyrosine-kinase inhibitor (TKI) therapy might display different characteristics. The aim of this study was to evaluate the influence of prior EGFR TKI therapy on the efficacy of subsequent pemetrexed plus platinum (PP) in advanced chemonaïve patients with EGFR-mutant lung adenocarcinoma.
  
  
  METHODS
  Advanced chemonaïve patients with EGFR-mutant lung adenocarcinoma receiving PP as first-line chemotherapy were enrolled retrospectively in two medical centers of Taiwan. The objective of this study was to compare objective response rate (ORR), disease-control rates (DCR), progression-free survival (PFS), and overall survival (OS) of PP in patients with and without prior EGFR TKI therapy.
  
  
  RESULTS
  In total, 105 patients were analyzed. Sixty-one patients (58.1%) had prior EGFR TKI therapy and used PP as second-line treatment. The other 44 patients (41.9%) received PP as first-line therapy. ORRs of PP in patients with and without prior EGFR TKI therapy were 24.6% and 38.6%, respectively (P=0.138). DCRs of the two groups were 62.3% and 65.9%, respectively (P=0.837). The median PFS (6.1 versus 6.1 months, P=0.639) and OS (34.4 versus 32.3 months, P=0.394) were comparable between the groups with and without prior EGFR TKI therapy. In a subgroup analysis of patients with prior EGFR TKI therapy, there was no significant association between the efficacy of first-line EGFR TKI and the outcome of subsequent PP therapy.
  
  
  CONCLUSIONS
  Our results suggested that prior EGFR TKI therapy would not influence the efficacy of subsequent PP therapy in advanced chemonaïve patients with EGFR-mutant lung adenocarcinoma.
authors.affiliation: Institute of Biomedical Sciences, National Chung-Hsing University, Taichung, Taiwan ; Division of Chest Medicine, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Jeng-Sen
authors.initials: JS
authors.lastname: Tseng
authors.affiliation: Division of Chest Medicine, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Tsung-Ying
authors.initials: TY
authors.lastname: Yang
authors.affiliation: Institute of Biomedical Sciences, National Chung-Hsing University, Taichung, Taiwan ; Division of Chest Medicine, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Kun-Chieh
authors.initials: KC
authors.lastname: Chen
authors.affiliation: Institute of Biomedical Sciences, National Chung-Hsing University, Taichung, Taiwan ; Division of Critical Care and Respiratory Therapy, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: Kuo-Hsuan
authors.initials: KH
authors.lastname: Hsu
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Chong-Jen
authors.initials: CJ
authors.lastname: Yu
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Wei-Yu
authors.initials: WY
authors.lastname: Liao
authors.affiliation: Department of Pediatrics, Taichung Veterans General Hospital, Taichung, Taiwan ; Institute of Molecular Biology, National Chung-Hsing University, Taichung, Taiwan.
authors.forename: Chi-Ren
authors.initials: CR
authors.lastname: Tsai
authors.affiliation: Division of Chest Medicine, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan ; Institute of Statistical Science, Academia Sinica, Taipei, Taiwan.
authors.forename: Meen-Hsin
authors.initials: MH
authors.lastname: Tsai
authors.affiliation: Department of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, Taipei, Taiwan ; Center for Optoelectronic Biomedicine, College of Medicine, National Taiwan University, Taipei, Taiwan ; Graduate Institute of Pathology, College of Medicine, National Taiwan University, Taipei, Taiwan ; Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Sung-Liang
authors.initials: SL
authors.lastname: Yu
authors.affiliation: Department of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, Taipei, Taiwan ; Center of Genomic Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: Kang-Yi
authors.initials: KY
authors.lastname: Su
authors.affiliation: Institute of Biomedical Sciences, National Chung-Hsing University, Taichung, Taiwan.
authors.forename: Jeremy Jw
authors.initials: JJ
authors.lastname: Chen
authors.affiliation: Institute of Statistical Science, Academia Sinica, Taipei, Taiwan.
authors.forename: Hsuan-Yu
authors.initials: HY
authors.lastname: Chen
authors.affiliation: Institute of Biomedical Sciences, National Chung-Hsing University, Taichung, Taiwan ; Division of Chest Medicine, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan ; School of Medicine, China Medical University, Taichung, Taiwan ; Comprehensive Cancer Center, Taichung Veterans General Hospital, Taichung, Taiwan ; Faculty of Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Gee-Chen
authors.initials: GC
authors.lastname: Chang
keywords: epidermal growth-factor receptor mutation; epidermal growth-factor receptor tyrosine-kinase inhibitor; non-small-cell lung cancer; pemetrexed