title: Long-term outcome and prognostic factors of surgically treated thymic carcinoma: results of 306 cases from a Japanese Nationwide Database Study.
abstract: OBJECTIVE
  Thymic carcinoma is a rare thymic malignancy. The purpose of this study was to evaluate the prognostic impact of clinicopathological variables and perioperative therapy for surgically treated thymic carcinoma using a nationwide database.
  
  
  METHODS
  Of 2835 patients with surgically treated thymic epithelial tumours collected from 32 Japanese institutions, a total of 306 patients with thymic carcinomas, excluding neuroendocrine tumours, were enrolled in this retrospective study. Multivariable Cox regression analyses were performed for overall (OS) and recurrence-free survival (RFS) after R0 resection.
  
  
  RESULTS
  Of 306 patients, 228 (75%) patients presented with Masaoka stage III-IV. Squamous cell carcinoma was the most common histological type (n = 216, 71%). R0 resection was performed in 181 (61%) patients, R1 in 46 (16%), R2 sub-total (≥80% tumour resection) in 43 (14%) and R2 non-resection in 27 (9%). The 5-year OS rate was 61%. Prognostic factors for OS were Masaoka stage and resection status. R0 resection was associated with most improved OS; however, both R1 and R2 sub-total resection resulted in superior OS compared with R2 non-resection [hazard ratio (95% confidence interval) for R0, R1 and R2 sub-total, 0.27 (0.15-0.48), 0.40 (0.22-0.74) and 0.38 (0.20-0.72), respectively]. Histological type and perioperative therapy did not affect OS, whereas tumour size and postoperative radiotherapy were associated with improved RFS after R0 resection.
  
  
  CONCLUSIONS
  R0 resection is essential for prolonged OS for surgically treated thymic carcinoma, but maximal debulking surgery might be beneficial and worth evaluating for advanced disease deemed difficult for R0 resection. The benefit of postoperative radiotherapy after R0 resection should also be evaluated prospectively.
authors.affiliation: Department of Thoracic Surgery, National Cancer Centre Hospital East, Chiba, Japan thishida@nifty.com.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Hishida
authors.affiliation: Center for Research Administration and Support, National Cancer Centre, Chiba, Japan.
authors.forename: Shogo
authors.initials: S
authors.lastname: Nomura
authors.affiliation: Department of Oncology, Immunology and Surgery, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
authors.forename: Motoki
authors.initials: M
authors.lastname: Yano
authors.affiliation: Department of Thoracic Surgery, National Cancer Centre Hospital, Tokyo, Japan Present address: Division of Thoracic Surgery, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Hisao
authors.initials: H
authors.lastname: Asamura
authors.affiliation: Department of Thoracic Surgery, Shikoku Cancer Centre, Ehime, Japan.
authors.forename: Motohiro
authors.initials: M
authors.lastname: Yamashita
authors.affiliation: Division of Thoracic Surgery, Shizuoka Cancer Centre, Shizuoka, Japan.
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Ohde
authors.affiliation: Department of Thoracic Surgery, Hokkaido Cancer Centre, Sapporo, Japan.
authors.forename: Keishi
authors.initials: K
authors.lastname: Kondo
authors.affiliation: Department of Thoracic Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Date
authors.affiliation: Department of Thoracic Surgery, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Meinoshin
authors.initials: M
authors.lastname: Okumura
authors.affiliation: Department of Thoracic Surgery, National Cancer Centre Hospital East, Chiba, Japan.
authors.forename: Kanji
authors.initials: K
authors.lastname: Nagai
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012008:Recurrence; D012189:Retrospective Studies; D013945:Thymoma / Q000453:epidemiology / Q000401:mortality* / Q000601:surgery*; D013953:Thymus Neoplasms / Q000453:epidemiology / Q000401:mortality* / Q000601:surgery*; D016896:Treatment Outcome; D055815:Young Adult
keywords: Masaoka stage; Radiation therapy; Resection status; Surgery; Thymic carcinoma