title: Prognosis and therapeutic response according to the World Health Organization histological classification in advanced thymoma.
abstract: OBJECTIVE
  The clinical efficacy of the World Health Organization (WHO) classification of thymoma has been reported to be a prognostic factor for patients with thymomas. This study focuses on the relationship between the therapeutic response and the WHO histological classification in patients with advanced thymoma.
  
  
  METHODS
  A retrospective review was performed on 22 patients with Masaoka stage III and IV thymoma treated from 1975 to 2007. There were 1, 1, 7, 3, and 10 patients with WHO histological subtypes A, AB, B1, B2, and B3, respectively.
  
  
  RESULTS
  Surgery was performed on 10 patients. There were 2 complete resections, 2 incomplete resections, and 6 exploratory thoracotomies. Of 18 patients with unresectable tumors, 8, 5, and 5 were treated with radiotherapy, chemotherapy, and chemoradiotherapy as the initial therapy, respectively. The response rate in 9 patients with type A-B2 was significantly better than that in 9 patients with type B3 regardless of treatment modality (100% vs 11.1%, P = 0.0001). Only the WHO classification was significantly associated with survival, with type B3 having a worse prognosis than A-B2 (P = 0.01).
  
  
  CONCLUSIONS
  Type B3 thymoma showed a lower response rate to treatments and thus shorter survival. The WHO classification is a good predictive factor for therapeutic response in advanced thymoma.
authors.affiliation: Department of Thoracic Oncology, National Kyushu Cancer Center, 3-1-1 Notame, Minami-ku, Fukuoka, 811-1395, Japan.
authors.forename: Tetsuzo
authors.initials: T
authors.lastname: Tagawa
authors.forename: Takuro
authors.initials: T
authors.lastname: Kometani
authors.forename: Koji
authors.initials: K
authors.lastname: Yamazaki
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Okamoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Wataya
authors.forename: Takashi
authors.initials: T
authors.lastname: Seto
authors.forename: Seiichi
authors.initials: S
authors.lastname: Fukuyama
authors.forename: Atsushi
authors.initials: A
authors.lastname: Osoegawa
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Hirai
authors.forename: Kenji
authors.initials: K
authors.lastname: Sugio
authors.forename: Yukito
authors.initials: Y
authors.lastname: Ichinose
mesh_terms: D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D059248:Chemoradiotherapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D011379:Prognosis; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D013908:Thoracotomy; D013945:Thymoma / Q000401:mortality* / Q000473:pathology* / Q000628:therapy; D013953:Thymus Neoplasms / Q000401:mortality* / Q000473:pathology* / Q000628:therapy; D014944:World Health Organization