title: Outcome of primary neuroendocrine tumors of the thymus: a joint analysis of the International Thymic Malignancy Interest Group and the European Society of Thoracic Surgeons databases.
abstract: OBJECTIVE
  Primary neuroendocrine tumors of the thymus (TNET) are exceedingly rare. We studied a large series of TNET identified through the International Thymic Malignancy Interest Group and the European Society of Thoracic Surgeons databases.
  
  
  METHODS
  This was a retrospective multicenter study of patients undergoing operation for TNET between 1984 and 2012. Outcome measures were: overall survival (OS) and cumulative incidence of recurrences (CIR). OS was analyzed using the Kaplan-Meier method and CIR was analyzed using competing risk analysis. Associations with clinical and prognostic factors for OS and CIR were evaluated using the log rank test and Gray test.
  
  
  RESULTS
  Two hundred five patients with TNET were treated: 25 patients received induction therapy (19 chemotherapy [CT] and 6 radiotherapy [RT]). Data about resection status were available in 47% of cases: complete resection was performed in 52 patients (54%). Masaoka-Koga stages I, II, III, and IV were observed in 12, 33, 56, and 47 patients, respectively. Atypical carcinoid was the commonest histologic subtype (71 cases; 40%). One hundred one patients with TNET received adjuvant treatment; 52 patients died and 36 experienced a recurrence. The median OS was 7.5 years; 5-year OS was 68%, and 5-year CIR was 39%. OS was significantly influenced by Masaoka-Koga stage (P = .02) and completeness of resection (P = .03). CIR significantly increased in high Masaoka-Koga stages (P = .04). Histologic subtype was not associated with either OS or CIR.
  
  
  CONCLUSIONS
  Our results confirm the high biologic aggressiveness of these rare neoplasms; pathologic stage and completeness of resection were demonstrated to be strong prognostic factors, whereas histology did not influence patients outcome.
authors.affiliation: Department of Thoracic Surgery, University of Torino, Torino, Italy. Electronic address: pierluigi.filosso@unito.it.
authors.forename: Pier Luigi
authors.initials: PL
authors.lastname: Filosso
authors.affiliation: Section of Medical Oncology, Department of Internal Medicine, Yale University School of Medicine, New Haven, Conn.
authors.forename: Xiaopan
authors.initials: X
authors.lastname: Yao
authors.affiliation: Thoracic Surgery, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Usman
authors.initials: U
authors.lastname: Ahmad
authors.affiliation: Section of Medical Oncology, Department of Internal Medicine, Yale University School of Medicine, New Haven, Conn.
authors.forename: Yilei
authors.initials: Y
authors.lastname: Zhan
authors.affiliation: Thoracic Surgery, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: James
authors.initials: J
authors.lastname: Huang
authors.affiliation: Department of Thoracic Surgery, University of Torino, Torino, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Ruffini
authors.affiliation: Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: William
authors.initials: W
authors.lastname: Travis
authors.affiliation: Division of Thoracic Surgery, Cardiac and Thoracic Department, Azienda Ospedaliero-Universitaria Pisana, Pisa, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Lucchi
authors.affiliation: Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Andreas
authors.initials: A
authors.lastname: Rimner
authors.affiliation: Department of Thoracic Surgery, Yale University School of Medicine, New Haven, Conn.
authors.forename: Alberto
authors.initials: A
authors.lastname: Antonicelli
authors.affiliation: Department of Thoracic Surgery, University of Torino, Torino, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Guerrera
authors.affiliation: Department of Thoracic Surgery, Yale University School of Medicine, New Haven, Conn.
authors.forename: Frank
authors.initials: F
authors.lastname: Detterbeck
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017024:Chemotherapy, Adjuvant; D016208:Databases, Factual; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D020360:Neoadjuvant Therapy; D060787:Neoplasm Grading; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D018358:Neuroendocrine Tumors / Q000401:mortality / Q000556:secondary / Q000601:surgery*; D016016:Proportional Hazards Models; D018714:Radiotherapy, Adjuvant; D012189:Retrospective Studies; D012307:Risk Factors; D013934:Thymectomy / Q000009:adverse effects / Q000401:mortality; D013953:Thymus Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult