title: Serum carcinoembryonic antigen levels before initial treatment are associated with EGFR mutations and EML4- ALK fusion gene in lung adenocarcinoma patients.
abstract: BACKGROUND
  Epidermal growth factor receptor (EGFR) mutations and echinoderm microtubule associated protein like 4-anaplastic lymphoma kinase (EML4-ALK) define specific molecular subsets of lung adenocarcinomas with distinct clinical features. Our purpose was to analyze clinical features and prognostic value of EGFR gene mutations and the EML4-ALK fusion gene in lung adenocarcinoma.
  
  
  METHODS
  EGFR gene mutations and the EML4-ALK fusion gene were detected in 92 lung adenocarcinoma patients in China. Tumor marker levels before first treatment were measured by electrochemiluminescence immunoassay.
  
  
  RESULTS
  EGFR mutations were found in 40.2% (37/92) of lung adenocarcinoma patients, being identified at high frequencies in never-smokers (48.3% vs. 26.5% in smokers; P=0.040) and in patients with abnormal serum carcinoembryonic antigen (CEA) levels before the initial treatment (58.3% vs. 28.6%, P=0.004). Multivariate analysis revealed that a higher serum CEA level before the initial treatment was independently associated with EGFR gene mutations (95%CI: 1.476~11.343, P=0.007). We also identified 8 patients who harbored the EML4-ALK fusion gene (8.7%, 8/92). In concordance with previous reports, younger age was a clinical feature for these (P=0.008). Seven of the positive cases were never smokers, and no coexistence with EGFR mutation was discovered. In addition, the frequency of the EML4-ALK fusion gene among patients with a serum CEA concentration below 5 ng/ml seemed to be higher than patients with a concentration over 5 ng/ml (P=0.021). No significant difference was observed for time to progression and overall survival between EML4-ALK-positive group and EML4-ALK-negative group or between patients with and without an EGFR mutation.
  
  
  CONCLUSIONS
  The serum CEA level before the initial treatment may be helpful in screening population for EGFR mutations or EML4-ALK fusion gene presence in lung adenocarcinoma patients.
authors.affiliation: Department of Thoracic Surgery, the Affiliated Tumor Hospital of Zhengzhou University, Zhengzhou, China E-mail : qinjianjun73@aliyun.com.
authors.forename: Wen-Tao
authors.initials: WT
authors.lastname: Wang
authors.forename: Yin
authors.initials: Y
authors.lastname: Li
authors.forename: Jie
authors.initials: J
authors.lastname: Ma
authors.forename: Xiao-Bing
authors.initials: XB
authors.lastname: Chen
authors.forename: Jian-Jun
authors.initials: JJ
authors.lastname: Qin
mesh_terms: D000230:Adenocarcinoma / Q000097:blood* / Q000235:genetics*; D000077192:Adenocarcinoma of Lung; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood / Q000235:genetics; D002272:Carcinoembryonic Antigen / Q000097:blood*; D066246:ErbB Receptors / Q000235:genetics*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000097:blood* / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D012907:Smoking
chemical_list: D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen; C522504:EML4-ALK fusion protein, human; D015514:Oncogene Proteins, Fusion; C512478:EGFR protein, human; D066246:ErbB Receptors