title: Limited effects of selenium substitution in the prevention of radiation-associated toxicities. results of a randomized study in head and neck cancer patients.
abstract: OBJECTIVE
  The substitution of selenium activates the selenium-dependent enzyme glutathione peroxidase, which is important for scavenging free radicals. To date, only limited data are available about the clinical impact of selenium regarding the toxicities due to free radical producing therapies, e.g. irradiation or chemotherapy, and therefore the objective of this study was to investigate the clinical impact of selenium in such therapies.
  
  
  METHODS
  39 patients (8 female, 31 male) with advanced head and neck cancer were included in a randomised phase II study. The mean age was 63.52+/-9.31 years. Tumour localizations: oral cavity 15 patients, oropharynx 19 patients, hypopharynx 5 patients, carcinoma of unknown primary 1 patient. Group A (n=22) received 500 microg sodium selenite on the days of radiotherapy and 300 microg sodium selenite on days without radiotherapy. Group B (17) was irradiated without any selenium substitution. Both groups were well balanced according to age, gender, localization and stage of the tumour. The RTOG grade of radiation-associated toxicities was evaluated once per week.
  
  
  RESULTS
  The following serious toxicities were observed (group A vs. group B): dysphagia 22.7% vs. 35.3%, loss of taste 22.7% vs. 47.1%, dry mouth 22.7% vs. 23.5%, and stomatitis 36.4% vs. 23.5%. A statistical trend (Fisher's exact test) was only seen for the loss of taste (p=0.172). The weekly patient analysis (Student's t-test) showed a significant reduction of dysphagia in the selenium group (Group 1) at the last week of irradiation.
  
  
  CONCLUSIONS
  This small randomised trial showed limited effects of selenium in the prevention of ageusia (loss of taste) and dysphagia due to radiotherapy of head and neck cancer.
authors.affiliation: Department of Otolaryngology, Head Neck Surgery, Sudharz-Krankenhaus Nordhausen, Nordhausen, Germany. jens.buentzel@shk-ndh.de
authors.forename: J
authors.initials: J
authors.lastname: Büntzel
authors.forename: D
authors.initials: D
authors.lastname: Riesenbeck
authors.forename: M
authors.initials: M
authors.lastname: Glatzel
authors.forename: R
authors.initials: R
authors.lastname: Berndt-Skorka
authors.forename: T
authors.initials: T
authors.lastname: Riedel
authors.forename: R
authors.initials: R
authors.lastname: Mücke
authors.forename: K
authors.initials: K
authors.lastname: Kisters
authors.forename: K G
authors.initials: KG
authors.lastname: Schönekaes
authors.forename: U
authors.initials: U
authors.lastname: Schäfer
authors.forename: F
authors.initials: F
authors.lastname: Bruns
authors.forename: O
authors.initials: O
authors.lastname: Micke
mesh_terms: D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000532:radiotherapy*; D003680:Deglutition Disorders / Q000473:pathology / Q000517:prevention & control; D005260:Female; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008495:Medical Oncology / Q000379:methods; D008875:Middle Aged; D052016:Mucositis / Q000517:prevention & control; D011832:Radiation Injuries / Q000473:pathology* / Q000517:prevention & control*; D018038:Sodium Selenite / Q000494:pharmacology*; D014987:Xerostomia / Q000517:prevention & control
chemical_list: D018038:Sodium Selenite