title: Survival impact of epidermal growth factor receptor overexpression in patients with non-small cell lung cancer: a meta-analysis.
abstract: BACKGROUND
  It is thought that overexpression of epidermal growth factor receptor (EGFR) in non-small cell lung cancer (NSCLC) might compromise patient survival, presumably by promoting tumour growth by an autocrine mechanism. However, conflicting results have been reported from various laboratories, and the clinical importance of EGFR overexpression remains unsettled.
  
  
  METHODS
  A meta-analysis of previous studies was performed to quantitatively review the effects of EGFR overexpression on survival in patients with NSCLC using a DerSimonian-Laird random effects model. Eighteen studies including 2972 patients were subjected to final analysis.
  
  
  RESULTS
  Overall, positivity for EGFR overexpression differed between histological types: 39% in adenocarcinomas, 58% in squamous cell carcinomas, 38% in large cell carcinomas, and 32% in cancers in a miscellaneous category (p<0.0001). The combined hazard ratio (HR) was 1.14 (95% CI 0.97 to 1.34; p = 0.103), indicating that EGFR overexpression has no significant impact on survival. When only the 15 immunohistochemistry based studies were considered, the combined HR was 1.08 (95% CI 0.92 to 1.28; p = 0.356), again suggesting that EGFR overexpression has no impact on survival. Heterogeneity testing indicated that there was heterogeneity between studies but publication bias was absent, which suggests that the summary statistics obtained may approximate the actual average.
  
  
  CONCLUSIONS
  EGFR overexpression was not associated with poorer survival in patients with NSCLC. Specific mutations of the EGFR gene will need further study in terms of survival implications.
authors.affiliation: Department of Chest Surgery, Atami Hospital, International University of Health and Welfare, 13-1 Higashikaigan-cho, Atami-shi, Shizuoka, 413-0012 Japan. h.nakamura@iuhw.ac.jp
authors.forename: H
authors.initials: H
authors.lastname: Nakamura
authors.forename: N
authors.initials: N
authors.lastname: Kawasaki
authors.forename: M
authors.initials: M
authors.lastname: Taguchi
authors.forename: K
authors.initials: K
authors.lastname: Kabasawa
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy / Q000378:metabolism / Q000401:mortality*; D004797:Enzyme-Linked Immunosorbent Assay; D066246:ErbB Receptors / Q000378:metabolism*; D000069347:Erlotinib Hydrochloride; D000077156:Gefitinib; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000401:mortality*; D011379:Prognosis; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use; D011799:Quinazolines / Q000627:therapeutic use; D012333:RNA, Messenger / Q000378:metabolism; D016019:Survival Analysis
chemical_list: D000970:Antineoplastic Agents; D047428:Protein Kinase Inhibitors; D011799:Quinazolines; D012333:RNA, Messenger; D000069347:Erlotinib Hydrochloride; D066246:ErbB Receptors; D000077156:Gefitinib