title: Adjuvant radiation therapy for high-grade and/or locally advanced major salivary gland tumors.
abstract: OBJECTIVE
  To examine the effect of adjuvant radiation therapy (RT) on survival of high-grade and/or locally advanced malignant major salivary gland tumors (MMSGT).
  
  
  METHODS
  The study population comprised 2170 patients with high-grade (poorly differentiated or undifferentiated) and/or locally advanced MMSGT (T3/4 or N+).
  
  
  METHODS
  The Surveillance, Epidemiology, and End Results registry was used to obtained data for all patients 20 years or older who underwent surgery for high-grade and/or locally advanced nonmetastatic MMSGT between 1988 and 2005. Univariate and multivariable regression analyses were performed to identify factors associated with improved survival.
  
  
  RESULTS
  Seventy-two percent of patients received adjuvant RT, while 28% underwent surgery alone. Patients receiving adjuvant RT were younger and had higher T and N categories and grade. Multivariable analysis revealed significantly improved survival with adjuvant RT (HR for mortality, 0.76; 95% CI, 0.65-0.89; P < .001). Other factors associated with improved survival included younger age at diagnosis, less than radical surgery, certain histologic subtypes, lower grade, and lower T and N categories. Subset analyses found significantly improved survival with adjuvant RT among patients with both high-grade and locally advanced disease (P < .001), involvement of the parotid gland (P = .002), or squamous cell carcinoma (P = .004), with a survival benefit seen among patients with adenocarcinoma that did not reach significance (P = .06).
  
  
  CONCLUSIONS
  Adjuvant RT is associated with improved survival for high-grade and/or locally advanced MMSGT based on analysis of this large, population-based database. Further prospective studies are warranted to examine the role of RT in the management of this disease.
authors: Department of Radiation Oncology, Marlene and Stewart Greenebaum Cancer Center, University of Maryland, 22 S Greene Street, Baltimore, MD 21201, USA. usama.mahmood@gmail.com
authors: Usama
authors: U
authors: Mahmood
authors: Matthew
authors: M
authors: Koshy
authors: Olga
authors: O
authors: Goloubeva
authors: Mohan
authors: M
authors: Suntharalingam
mesh_terms: D000328:Adult; D000369:Aged, 80 and over; D002277:Carcinoma / Q000401:mortality / Q000473:pathology* / Q000532:radiotherapy*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D060787:Neoplasm Grading; D018714:Radiotherapy, Adjuvant; D018426:SEER Program; D012468:Salivary Gland Neoplasms / Q000401:mortality / Q000473:pathology* / Q000532:radiotherapy*; D016019:Survival Analysis; D015996:Survival Rate; D014481:United States; D055815:Young Adult