title: EGFR mutation and brain metastasis in pulmonary adenocarcinomas.
abstract: BACKGROUND
  This study aimed to explore the potential association of mutation in the epidermal growth factor receptor (EGFR) with brain metastases in patients with pulmonary adenocarcinoma.
  
  
  METHODS
  We analyzed clinical data on 314 patients who were tested for EGFR mutation and underwent brain magnetic resonance imaging at diagnosis. The relationship between EGFR mutation status and brain metastases at the initial presentation was analyzed. In addition, prognostic significance of EGFR mutational status on the risk of brain metastasis was evaluated in subgroups of surgically treated patients.
  
  
  RESULTS
  Of the 314 patients, 138 patients (43.9%) had EGFR mutations. The frequency of EGFR mutation was statistically higher for patients with brain metastases (64.7%, brain metastases; 39.8%, no metastases; 40.2%, extracranial metastases; p = 0.005). A strong association between EGFR mutation status and brain metastasis was observed (adjusted odds ratio = 3.83, p = 0.001), whereas no association was observed between EGFR mutation status and extracranial metastases (adjusted odds ratio = 1.73, p = 0.079). In addition, the number of brain metastases was significantly correlated with the EGFR mutation status (p = 0.029). Further analysis of 133 patients treated with surgical resection showed that EGFR mutation status was a poor prognostic factor for the risk of brain metastasis (hazard ratio = 4.49, p = 0.026) after adjustment for pathologic N stage.
  
  
  CONCLUSIONS
  We found a significant association between EGFR mutation and risk of brain metastases at the time of diagnosis and follow-up after curative resection for pulmonary adenocarcinoma. This result indicates the distinct clinical features of EGFR-mutated tumors in terms of brain metastases.
authors.affiliation: *Department of Internal Medicine, Division of Hematology/Oncology †Department of Internal Medicine, Division of Pulmonology, ‡Department of Pathology, and §Department of Thoracic Surgery, Korea Cancer Center Hospital, Korea Institute of Radiological and Medical Sciences, Seoul, Korea.
authors.forename: Dong-Yeop
authors.initials: DY
authors.lastname: Shin
authors.forename: Im Il
authors.initials: II
authors.lastname: Na
authors.forename: Cheol Hyeon
authors.initials: CH
authors.lastname: Kim
authors.forename: Sunhoo
authors.initials: S
authors.lastname: Park
authors.forename: HeeJong
authors.initials: H
authors.lastname: Baek
authors.forename: Sung Hyun
authors.initials: SH
authors.lastname: Yang
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000235:genetics* / Q000556:secondary; D066246:ErbB Receptors / Q000235:genetics*; D005260:Female; D005500:Follow-Up Studies; D005838:Genotype; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics*; D009367:Neoplasm Staging; D016133:Polymerase Chain Reaction; D011379:Prognosis
chemical_list: C512478:EGFR protein, human; D066246:ErbB Receptors