title: The use of radiation therapy appears to improve outcome in patients with malignant primary tracheal tumors: a SEER-based analysis.
abstract: OBJECTIVE
  To conduct a matched pair analysis assessing the impact of radiotherapy (RT) in patients with resectable and unresectable primary malignant tracheal tumors using Surveillance, Epidemiology and End Results (SEER) database.
  
  
  METHODS
  The SEER registry was used to identify every patient (or "case") who received RT between 1988 and 2007 for primary malignant tracheal tumors, and to search for corresponding "controls" (not treated with RT), with the same prognostic and treatment factors (surgery on the trachea, disease extension, histology, and gender). Overall survival (OS) was calculated with the Kaplan-Meier methods. Results of OS and cumulative incidence of death from tracheal cancer in the cases and controls, and in various subsets, were compared using log-rank and Gray's tests.
  
  
  RESULTS
  Two hundred fifty-eight patients who received RT were identified, and 78 of these had appropriate matched controls identified, forming the basis of this analysis. In the 78 (+RT) cases, the median follow-up was 60 months (range, 10-192) in the survivors vs. 55 months (range, 2-187) in the controls (no-RT group). Patients in RT group had significantly better OS, and a lower cumulative incidence of death from tracheal cancer than no-RT patients (p < 0.05). Treatment with radiation was associated with improved survival in patients with squamous cell histology [p < 0.0001], regional disease extension [p = 0.030], or those that did not undergo resection [p = 0.038]. There were four deaths in RT group and three in no-RT group attributed to cardiac and respiratory causes.
  
  
  CONCLUSIONS
  Our data suggest a survival benefit for the use of RT broadly for all patients with tracheal cancer. Nevertheless, the retrospective nature of this observational study limits its interpretation.
authors.affiliation: Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai, China.
authors.forename: Liyi
authors.initials: L
authors.lastname: Xie
authors.forename: Min
authors.initials: M
authors.lastname: Fan
authors.forename: Nathan C
authors.initials: NC
authors.lastname: Sheets
authors.forename: Ronald C
authors.initials: RC
authors.lastname: Chen
authors.forename: Guo-Liang
authors.initials: GL
authors.lastname: Jiang
authors.forename: Lawrence B
authors.initials: LB
authors.lastname: Marks
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D002423:Cause of Death; D005260:Female; D006801:Humans; D008297:Male; D016555:Matched-Pair Analysis; D008875:Middle Aged; D012189:Retrospective Studies; D018426:SEER Program; D016019:Survival Analysis; D014134:Tracheal Neoplasms / Q000401:mortality* / Q000473:pathology / Q000532:radiotherapy*; D016896:Treatment Outcome; D055815:Young Adult