title: Metastatic brain tumors from non-small cell lung cancer with EGFR mutations: distinguishing influence of exon 19 deletion on radiographic features.
abstract: BACKGROUND
  Miliary brain metastasis is a rarity and refers to the presence of numerous small tumors in a perivascular distribution without intraparenchymal invasion and focal edema. Although the presence of epidermal growth factor receptor (EGFR) mutation and good response to gefitinib have been reported in non-small cell lung cancer (NSCLC) patients with miliary brain metastases, the influence of the EGFR mutations on the radiographic features remains unclear.
  
  
  METHODS
  All NSCLC patients with synchronous brain metastases detected at the time of a new diagnosis of NSCLC from March 2005 through May 2011 were divided according to EGFR mutation status. The number of brain tumors, size of the largest brain tumors, and size of peritumoral brain edema were compared among the groups.
  
  
  RESULTS
  Fifty-seven patients who met the criteria were divided into three groups: wild-type EGFR group (31 patients), exon 19 deletion group (18 patients), and exon 21 point mutation group (8 patients). The exon 19 deletion group had more multiple and smaller brain tumors with smaller peritumoral brain edema than did the wild-type group (P = 0.024, P = 0.0016, and P = 0.0036, respectively). The exon 21 point mutation group showed no significant difference in any of the radiographic values when compared with the wild-type group.
  
  
  CONCLUSIONS
  Our results indicate that NSCLC patients with the exon 19 deletion have such a peculiar pattern of brain metastases as multiple small metastases with small brain edema. This metastatic pattern may be similar to that of miliary brain metastases. Because it is unclear whether or not severe neurologic symptoms develop during their clinical courses like miliary brain metastases, regular evaluation with brain magnetic resonance imaging (MRI) should be considered, regardless of the presence of neurologic symptoms. Accumulation of knowledge about specific pattern of brain metastasis will help approach to "individual" management.
authors.affiliation: Department of Respiratory Medicine, Kanagawa Prefectural Cardiovascular and Respiratory Center, Yokohama, Japan. Akimasa.Sekine@gmail.com
authors.forename: Akimasa
authors.initials: A
authors.lastname: Sekine
authors.forename: Terufumi
authors.initials: T
authors.lastname: Kato
authors.forename: Eri
authors.initials: E
authors.lastname: Hagiwara
authors.forename: Takeshi
authors.initials: T
authors.lastname: Shinohara
authors.forename: Takanobu
authors.initials: T
authors.lastname: Komagata
authors.forename: Tae
authors.initials: T
authors.lastname: Iwasawa
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Satoh
authors.forename: Katsumi
authors.initials: K
authors.lastname: Tamura
authors.forename: Tomotaka
authors.initials: T
authors.lastname: Kasamatsu
authors.forename: Kenji
authors.initials: K
authors.lastname: Hayashihara
authors.forename: Takefumi
authors.initials: T
authors.lastname: Saito
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takahashi
authors.forename: Takashi
authors.initials: T
authors.lastname: Ogura
mesh_terms: D001932:Brain Neoplasms / Q000000981:diagnostic imaging / Q000235:genetics / Q000556:secondary*; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging / Q000235:genetics / Q000556:secondary*; D004252:DNA Mutational Analysis; D004487:Edema / Q000000981:diagnostic imaging; D066246:ErbB Receptors / Q000235:genetics*; D005091:Exons; D005260:Female; D056726:Genetic Association Studies; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000235:genetics / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012189:Retrospective Studies; D017384:Sequence Deletion; D047368:Tumor Burden
chemical_list: C512478:EGFR protein, human; D066246:ErbB Receptors