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Objective: The substitution of selenium effects in activation of the selenium dependent enzyme glutathione peroxidase which is important for scavenging free radicals. Until today only limited data was available about the clinical impact of selenium regarding the toxicities due to free radical producing therapies, e.g. irradiation or chemotherapy. Material and methods: 39 patients (8 female, 31 male) with advanced head neck cancer were included to a randomized Phase II study. The mean age was 63.52 ± 9.31 years. Tumor localizations: oral cancer 15 patients, oropharynx 19 patients, hypopharynx 5 patients, CUP 1 patient. Group A (n = 22) received 500 μg sodium selenite at the days of radiotherapy and 300 μg sodium selenite at holidays or weekend. Group B (17) was irradiated without any selenium substitution. Both groups were well balanced according age, gender, localization and stage of the tumor. We evaluated the RTOG grade of radiation-associated toxicities once per week. Results: We observed the following serious toxicities (Group A versus 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) is only seen in the area of loss of taste (p = 0,172). The analysis per week (Student t-test) had shown a significant reduction of dysphagia in the selenium group at the last week of irradiation. Conclusion: The small randomized trial has shown limited effects of selenium in the prevention of ageusia (loss of taste) and dysphagia due to radiotherapy because of head and neck cancer. [ABSTRACT FROM AUTHOR]

Selenium values of serum and whole blood were determined for two groups of patients undergoing large surgical interventions (e.g., gastrectomy) and receiving a total parenteral nutrition (TPN). All patients showed low selenium values at the beginning of TPN. The first group received a supplementation of selenium, and it was established that selenium levels normalized after 6-7 d. The balances of selenium turned out to be positive in all cases. The second group, which was not administered selenium supplementation, showed significantly lower values of selenium. It can, therefore, be concluded that a substitution of selenium prior to large surgical interventions following TPN clearly helps patients combat the increase in the oxidant stress reactions. [ABSTRACT FROM AUTHOR]