title: Neutron therapy, prognostic factors and dedifferentiation of adenoid cystic carcinomas (ACC) of salivary glands.
abstract: OBJECTIVE
  Analysis of the efficacy of fast neutron radiotherapy in the treatment of adenoid cystic carcinomas (ACC) of the salivary glands, identification of prognostic variables and dedifferentiation after radiotherapy.
  
  
  METHODS
  Histological slides of primary and recurrent lesions of 71 patients were reviewed to confirm the diagnosis and to analyse subtypes. Median follow-up was 52 months. Local control rate and overall survival were analysed in multivariate analysis. Complications are also described.
  
  
  RESULTS
  Primary vs. recurrent therapy (p=0.001), margin-status (p=0.01) and subtype (p=0.019) influenced overall survival. Primary vs. recurrent therapy (p=0.001), margin-status (p=0.018) and T-stage (p=0.043) influenced local control rate. Dedifferentiation was seen in only 1/17 cases.
  
  
  CONCLUSIONS
  The calculated prognostic factors illustrate the importance of a radical primary therapy. Histological subtype is a significant additional factor for overall survival and, in case of dedifferentiation, it is a strong predictor of a detrimental outcome.
authors.affiliation: Department of Radiation Oncology, Friedrich-Ebert-Hospital, 24534 Neumünster, Germany. sophie@brackrock.de
authors.forename: Sophie
authors.initials: S
authors.lastname: Brackrock
authors.forename: Andreas
authors.initials: A
authors.lastname: Krüll
authors.forename: Kerstin
authors.initials: K
authors.lastname: Röser
authors.forename: Rudolf
authors.initials: R
authors.lastname: Schwarz
authors.forename: Lutz
authors.initials: L
authors.lastname: Riethdorf
authors.forename: Winfried
authors.initials: W
authors.lastname: Alberti
mesh_terms: D000328:Adult; D000368:Aged; D003528:Carcinoma, Adenoid Cystic / Q000473:pathology / Q000532:radiotherapy*; D002454:Cell Differentiation; D005214:Fast Neutrons / Q000009:adverse effects / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local; D011379:Prognosis; D012189:Retrospective Studies; D012468:Salivary Gland Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D015996:Survival Rate; D013997:Time Factors