title: Prognostic factors for cure, recurrence and long-term survival after surgical resection of thymoma.
abstract: BACKGROUND
  To determine long-term outcome and risk factors for recurrence after thymectomy.
  
  
  METHODS
  Patients who underwent thymectomy (n = 262) for a thymic tumor (1986-2010) were identified from a prospective database. Patients were classified according to World Helath Organization (WHO) histologic classification, Masaoka staging system, and completeness of resection. Risk factors for recurrence: WHO histology, tumor size, Masaoka stage and completeness of resection were analyzed.
  
  
  RESULTS
  Of 262 patients, 51% were female, median age was 55 years, and 39% had myasthenia gravis. Median follow-up was 7.5 years, median tumor size was 5.4 cm, and Masaoka stage distribution was: I (25%), II (47%), III (17%), IV (4%), and (7%) not classified. Of 200 patients classified under the WHO system, there were (7%) type A, (22%) type AB, and (71%) type B; 83% had complete resection. One-hundred and sixty-nine patients received adjuvant radiotherapy, eight adjuvant chemoradiotherapy and 14 neoadjuvant chemoradiotherapy. Overall survival was 95% at 5 years, 91% at 10 years and 91% at 15 years. Recurrence occurred in 12 patients and disease-related death in four patients. Five patients underwent re-resection for recurrence with survival of 2-15 years. Only Masaoka stage and tumor size were associated with statistically significant risk of recurrence on multivariate analysis.
  
  
  CONCLUSIONS
  Resectable thymoma is associated with excellent prognosis. Aggressive resection of recurrent disease yielded excellent long-term results. Higher Masaoka stage is associated with a greater chance of incomplete resection. Higher Masaoka stage and increasing tumor size are independent factors associated with recurrence.
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Toronto General Hospital, University of Toronto, Toronto, ON, Canada.
authors.forename: Najib
authors.initials: N
authors.lastname: Safieddine
authors.affiliation: Department of Medical Oncology, University of Toronto, Toronto, ON, Canada.
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Liu
authors.affiliation: Department of Pathology, University of Toronto, Toronto, ON, Canada.
authors.forename: Kris
authors.initials: K
authors.lastname: Cuningham
authors.affiliation: Department of Pathology, University of Toronto, Toronto, ON, Canada.
authors.forename: Tsao
authors.initials: T
authors.lastname: Ming
authors.affiliation: Department of Pathology, University of Toronto, Toronto, ON, Canada.
authors.forename: David
authors.initials: D
authors.lastname: Hwang
authors.affiliation: Department of Radiation Oncology, University of Toronto, Toronto, ON, Canada.
authors.forename: Anthony
authors.initials: A
authors.lastname: Brade
authors.affiliation: Department of Radiation Oncology, University of Toronto, Toronto, ON, Canada.
authors.forename: Andrea
authors.initials: A
authors.lastname: Bezjak
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Toronto General Hospital, University of Toronto, Toronto, ON, Canada.
authors.forename: Stefan
authors.initials: S
authors.lastname: Fischer
authors.affiliation: Department of Biostatistics, Princess Margaret Cancer Centre at UHN, University of Toronto, Toronto, ON, Canada.
authors.forename: Wei
authors.initials: W
authors.lastname: Xu
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Toronto General Hospital, University of Toronto, Toronto, ON, Canada.
authors.forename: Sassan
authors.initials: S
authors.lastname: Azad
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Toronto General Hospital, University of Toronto, Toronto, ON, Canada.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Cypel
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Toronto General Hospital, University of Toronto, Toronto, ON, Canada.
authors.forename: Gail
authors.initials: G
authors.lastname: Darling
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Toronto General Hospital, University of Toronto, Toronto, ON, Canada.
authors.forename: Kazu
authors.initials: K
authors.lastname: Yasufuku
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Toronto General Hospital, University of Toronto, Toronto, ON, Canada.
authors.forename: Andrew
authors.initials: A
authors.lastname: Pierre
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Toronto General Hospital, University of Toronto, Toronto, ON, Canada.
authors.forename: Marc
authors.initials: M
authors.lastname: de Perrot
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Toronto General Hospital, University of Toronto, Toronto, ON, Canada.
authors.forename: Tom
authors.initials: T
authors.lastname: Waddell
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Toronto General Hospital, University of Toronto, Toronto, ON, Canada. Electronic address: shaf.keshavjee@uhn.ca.
authors.forename: Shaf
authors.initials: S
authors.lastname: Keshavjee
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D059186:Chemoradiotherapy, Adjuvant; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009364:Neoplasm Recurrence, Local / Q000601:surgery*; D009367:Neoplasm Staging; D011379:Prognosis; D018714:Radiotherapy, Adjuvant; D012307:Risk Factors; D015996:Survival Rate; D013934:Thymectomy; D013945:Thymoma / Q000145:classification / Q000473:pathology* / Q000628:therapy*; D013953:Thymus Neoplasms / Q000145:classification / Q000473:pathology* / Q000628:therapy*; D047368:Tumor Burden; D014944:World Health Organization; D055815:Young Adult