title: Factors that predict progression-free survival in Chinese lung adenocarcinoma patients treated with epidermal growth factor receptor tyrosine kinase inhibitors.
abstract: BACKGROUND
  Although first-generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have shown efficacy in patients with advanced lung cancers, survival predictors with these drugs have not been extensively investigated. This study was performed to explore factors that may predict progression-free survival (PFS) in Chinese lung adenocarcinoma patients treated with EGFR-TKIs.
  
  
  METHODS
  We retrospectively collected clinicopathologic data on 208 patients who received either gefitinib, erlotinib or icotinib, including the patients' EGFR mutation status and levels of six serum tumor markers [carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), cancer antigen 125 (CA125), squamous cell carcinoma antigen (SCC), cytokeratin-19 fragments (CYFRA21-1) and lactate dehydrogenase (LDH)]. Univariate and multivariate survival analyses were performed to identify independent prognostic factors associated with PFS.
  
  
  RESULTS
  At the study cutoff date, 189 (90.9%) of the patients met the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.0 criteria for progressive disease (PD), while 19 (9.1%) had stable disease (SD). The median PFS of the 208 patients was 12.4 months (95% CI, 11.0-13.8 months). In the multivariate analysis using a Cox proportional hazard model, a non-smoking history [hazard ratio (HR) =2.460; 95% CI, 1.484-4.079; P<0.001], first-line treatment (HR =1.500; 95% CI, 1.062-2.119; P=0.021), and a high pretreatment serum level of CEA (HR =1.424; 95% CI 1.026-1.977; P=0.035) were found to be significant predictors of a longer PFS.
  
  
  CONCLUSIONS
  In Chinese lung adenocarcinoma patients treated with EGFR-TKIs, a non-smoking history, first-line EGFR-TKIs treatment and a high serum level of CEA were independent predictors of a longer PFS along with an EGFR-activating mutation.
authors.affiliation: Department of Pulmonary Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai 200030, China.
authors.forename: Shaohua
authors.initials: S
authors.lastname: Cui
authors.affiliation: Department of Pulmonary Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai 200030, China.
authors.forename: Liwen
authors.initials: L
authors.lastname: Xiong
authors.affiliation: Department of Pulmonary Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai 200030, China.
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Lou
authors.affiliation: Department of Pulmonary Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai 200030, China.
authors.forename: Huangping
authors.initials: H
authors.lastname: Shi
authors.affiliation: Department of Pulmonary Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai 200030, China.
authors.forename: Aiqin
authors.initials: A
authors.lastname: Gu
authors.affiliation: Department of Pulmonary Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai 200030, China.
authors.forename: Yizhuo
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Department of Pulmonary Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai 200030, China.
authors.forename: Tianqing
authors.initials: T
authors.lastname: Chu
authors.affiliation: Department of Pulmonary Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai 200030, China.
authors.forename: Huimin
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Pulmonary Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai 200030, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Department of Pulmonary Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai 200030, China.
authors.forename: Lili
authors.initials: L
authors.lastname: Dong
authors.affiliation: Department of Pulmonary Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai 200030, China.
authors.forename: Liyan
authors.initials: L
authors.lastname: Jiang
keywords: Epidermal growth factor receptor (EGFR); lung adenocarcinoma; progression-free survival (PFS); tyrosine kinase inhibitors (TKIs)