title: The Impact of Postoperative Radiotherapy for Thymoma and Thymic Carcinoma.
abstract: The optimal role for postoperative radiotherapy (PORT) for thymoma and thymic carcinoma remains controversial. We used the National Cancer Data Base to investigate the impact of PORT on overall survival (OS).
  
  
  
  Patients who underwent an operation for thymoma or thymic carcinoma were categorized into Masaoka-Koga stage groups I to IIA, IIB, III, and IV. Patients who did not undergo an operation or those who received preoperative radiation were excluded. Kaplan-Meier estimates of OS and univariate and multivariate Cox proportional hazards regression analyses were performed. Propensity score-matched analyses were performed to further control for baseline confounders.
  
  
  
  From 2004 to 2012, 4056 patients were eligible for inclusion, 2001 of whom (49%) received PORT. On multivariate analysis of OS in the thymoma cohort adjusted for age, WHO histologic subtype, Masaoka-Koga stage group, surgical margins, and chemotherapy administration, PORT was associated with superior OS (hazard ratio [HR] = 0.72, p = 0.001). Propensity score-matched analyses confirmed the survival advantage associated with PORT. Subset analysis indicated longer OS in association with PORT for patients with stage IIB thymoma (HR = 0.61, p = 0.035), stage III (HR = 0.69, p = 0.020), and positive margins (HR = 0.53, p < 0.001). The impact of PORT for stage I to IIA disease did not reach significance (HR = 0.76, p = 0.156).
  
  
  
  In this large database analysis of PORT for thymic tumors, PORT was associated with longer OS, with the greatest relative benefits observed for stage IIB to III disease and positive margins. In the absence of randomized studies assessing the value of PORT, these data may inform clinical practice.
authors.affiliation: Department of Radiation Oncology, University of Colorado Cancer Center, Aurora, Colorado. Electronic address: matthew.jackson@ucdenver.edu.
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Jackson
authors.affiliation: London Health Sciences Centre, London, Ontario, Canada.
authors.forename: David A
authors.initials: DA
authors.lastname: Palma
authors.affiliation: Division of Medical Oncology, University of Colorado Cancer Center, Aurora, Colorado.
authors.forename: D Ross
authors.initials: DR
authors.lastname: Camidge
authors.affiliation: Department of Radiation Oncology, University of Colorado Cancer Center, Aurora, Colorado.
authors.forename: Bernard L
authors.initials: BL
authors.lastname: Jones
authors.affiliation: Department of Radiation Oncology, University of Colorado Cancer Center, Aurora, Colorado.
authors.forename: Tyler P
authors.initials: TP
authors.lastname: Robin
authors.affiliation: Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas.
authors.forename: David J
authors.initials: DJ
authors.lastname: Sher
authors.affiliation: Department of Radiation Oncology and Cellular Oncology, Department of Radiation Oncology, University of Illinois at Chicago, Chicago, Illinois.
authors.forename: Matthew
authors.initials: M
authors.lastname: Koshy
authors.affiliation: Department of Radiation Oncology, University of Colorado Cancer Center, Aurora, Colorado.
authors.forename: Brian D
authors.initials: BD
authors.lastname: Kavanagh
authors.affiliation: Department of Radiation Oncology, University of Colorado Cancer Center, Aurora, Colorado.
authors.forename: Laurie E
authors.initials: LE
authors.lastname: Gaspar
authors.affiliation: Department of Radiation Oncology, University of Colorado Cancer Center, Aurora, Colorado.
authors.forename: Chad G
authors.initials: CG
authors.lastname: Rusthoven
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016208:Databases, Factual; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011182:Postoperative Care / Q000401:mortality*; D011379:Prognosis; D011879:Radiotherapy Dosage; D020266:Radiotherapy, Conformal / Q000401:mortality*; D012189:Retrospective Studies; D015996:Survival Rate; D013945:Thymoma / Q000401:mortality* / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D013953:Thymus Neoplasms / Q000401:mortality* / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D055815:Young Adult
keywords: Adjuvant radiation; National Cancer Data Base; Postoperative radiotherapy; Thymic carcinoma; Thymoma