title: Brain metastasis effectively treated with erlotinib following the acquisition of resistance to gefitinib: a case report.
abstract: BACKGROUND
  Non-small-cell lung cancer harboring an activated epidermal growth factor receptor mutation exhibits a good response to epidermal growth factor receptor-tyrosine kinase inhibitors; however, clinicians often experience treatment failure following the development of resistance to epidermal growth factor receptor-tyrosine kinase inhibitor.
  
  
  METHODS
  We here report a case of a 56-year-old Japanese woman with non-small-cell lung carcinoma with a secondary T790M mutation associated with resistance to epidermal growth factor receptor-tyrosine kinase inhibitor that maintained sensitivity of brain metastases to epidermal growth factor receptor-tyrosine kinase inhibitor. An autopsy showed that the primary focus had a T790M mutation; however, no mutations of T790M were found in the brain metastases.
  
  
  CONCLUSIONS
  This case demonstrates the detection of T790M was associated with the clinical responsiveness to epidermal growth factor receptor-tyrosine kinase inhibitor.
authors.affiliation: Division of Respirology NTT Medical Center TOKYO, 5-9-22 Higashigotanda, Shinagawa, Tokyo 141-8625, Japan. sayakaohara@gmail.com.
authors.forename: Sayaka
authors.initials: S
authors.lastname: Ohara
authors.forename: Tomonori
authors.initials: T
authors.lastname: Ushijima
authors.forename: Mariko
authors.initials: M
authors.lastname: Gunji
authors.forename: Chiharu
authors.initials: C
authors.lastname: Tanai
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Noda
authors.forename: Hajime
authors.initials: H
authors.lastname: Horiuchi
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Usui