title: Surgical management of recurrent thymic epithelial tumors: a retrospective analysis based on the Japanese nationwide database.
abstract: BACKGROUND
  There is no standard treatment for recurrent thymic epithelial tumors. Although the efficacy has not been validated based on the large series studies, surgical resection is sometimes employed for patients with recurrent thymic tumors. The aim of this study is to evaluate the surgical outcomes for recurrent thymic epithelial tumors based on the Japanese nationwide database.
  
  
  METHODS
  From the database of patients whose thymic epithelial tumors were treated surgically from 1991 through 2010, the cohort who developed recurrence after the initial resection was extracted. Clinicopathological factors were reviewed, and the prognostic factors of re-resected cases were examined.
  
  
  RESULTS
  Twenty-eight hundred thirty-five patients who underwent surgical resection of thymic epithelial tumors were registered to the database. Among these patients, 420 (14.8%) experienced recurrence. One hundred sixty-two patients were treated surgically and 243 were treated nonsurgically for recurrent disease. The 5- and 10-year postrecurrence survival rates were 82.7% and 68.2%, respectively, in the surgery group and 43.5% and 25.4%, respectively, in the nonsurgery group (p < 0.001). According to univariate analyses, female sex and the pathological Masaoka I-II stage, nonthymic carcinoma, absence of preoperative treatment and longer recurrent-free interval (RFI) were significantly favorable factors for survival in the surgery group. According to the multivariate analysis, nonthymic carcinoma histology and longer RFI were identified to be independent prognostic factors.
  
  
  CONCLUSIONS
  The surgical outcomes of recurrent thymic epithelial tumors are favorable in selected patients. The role of re-resection may be limited in the setting of thymic carcinoma and/or a short RFI.
authors.affiliation: *Department of Thoracic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan; †Department of General Thoracic Surgery, Osaka University Graduate School of Medicine, Osaka, Japan; ‡Division of Thoracic Surgery, National Cancer Center Hospital, Tokyo, Japan; §Department of Thoracic Surgery, Shinshu University School of Medicine, Matsumoto, Japan; ‖Division of Thoracic Surgery, Respiratory Disease Center, Seirei Mikatahara General Hospital, Hamamatsu, Japan; ¶Department of Thoracic, Endocrine Surgery, and Oncology, Institute of Health Bioscience, the University of Tokushima, Tokushima, Japan; #Department of General Thoracic Surgery, Tokyo Metropolitan Cancer and Infectious Diseases Center, Komagome Hospital, Tokyo, Japan; and **Department of Surgery, National Hospital Organization Kinki-Chuo Chest Medical Center, Sakai, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Mizuno
authors.forename: Meinoshin
authors.initials: M
authors.lastname: Okumura
authors.forename: Hisao
authors.initials: H
authors.lastname: Asamura
authors.forename: Kazuo
authors.initials: K
authors.lastname: Yoshida
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Niwa
authors.forename: Kazuya
authors.initials: K
authors.lastname: Kondo
authors.forename: Hirotoshi
authors.initials: H
authors.lastname: Horio
authors.forename: Akihide
authors.initials: A
authors.lastname: Matsumura
authors.forename: Kohei
authors.initials: K
authors.lastname: Yokoi
mesh_terms: D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology; D009375:Neoplasms, Glandular and Epithelial / Q000453:epidemiology / Q000601:surgery*; D011379:Prognosis; D012189:Retrospective Studies; D016019:Survival Analysis; D013953:Thymus Neoplasms / Q000453:epidemiology / Q000601:surgery*