title: Older Age Modifies Oncologic Outcome Following Radiotherapy in Soft-tissue Sarcoma: A Subtype-specific SEER Analysis.
abstract: BACKGROUND
  Given the immune-mediated mechanisms of radiotherapy (RT), we hypothesized that age would affect response to RT in patients with soft-tissue sarcoma (STS) undergoing surgery.
  
  
  METHODS
  Using the Surveillance, Epidemiology, and End Results Program (1990-2011), we identified 15,380 patients with non-metastatic STS. Stratified by age (≥65 years) and histological subtype, we assessed predictors of overall (OS) and disease-specific survival (DSS).
  
  
  RESULTS
  Treatment with RT was associated with improved OS and DSS compared to surgery alone (p<0.05). Multivariate analysis also demonstrated that older patients obtained significant improvements in OS following RT, while younger patients did not. Results for DSS were similar, with older patients with leiomyosarcoma, sarcoma not otherwise specified, and myxoid liposarcoma, in particular, showing greater improvements in DSS after RT than younger patients (p<0.05). Interaction testing demonstrated an impact of year of diagnosis on outcomes but not receipt of RT.
  
  
  CONCLUSIONS
  Among patients with STS undergoing surgery, age appears to impact oncological outcomes after RT.
authors.affiliation: Department of Surgery, UC Davis School of Medicine, Sacramento, CA, U.S.A.
authors.forename: Noah K
authors.initials: NK
authors.lastname: Yuen
authors.affiliation: Division of Biostatistics, Department of Public Health Sciences, UC Davis School of Medicine, Sacramento, CA, U.S.A.
authors.forename: Chin-Shang
authors.initials: CS
authors.lastname: Li
authors.affiliation: Department of Radiation Oncology UC Davis School of Medicine, Sacramento, CA, U.S.A.
authors.forename: Arta M
authors.initials: AM
authors.lastname: Monjazeb
authors.affiliation: Department of Pathology, Stritch School of Medicine, Loyola University, Maywood, IL, U.S.A.
authors.forename: Dariusz
authors.initials: D
authors.lastname: Borys
authors.affiliation: Department of Surgery, UC Davis School of Medicine, Sacramento, CA, U.S.A.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Bold
authors.affiliation: Department of Surgery, UC Davis School of Medicine, Sacramento, CA, U.S.A. rjcanter@ucdavis.edu.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Canter
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D007890:Leiomyosarcoma / Q000473:pathology / Q000532:radiotherapy; D018208:Liposarcoma, Myxoid / Q000473:pathology / Q000532:radiotherapy; D008297:Male; D008875:Middle Aged; D018714:Radiotherapy, Adjuvant / Q000379:methods; D018426:SEER Program; D012509:Sarcoma / Q000473:pathology* / Q000532:radiotherapy*
keywords: Soft-tissue sarcoma; age; histology; radiotherapy; surgery; survival