Introduction: Se measurement and supplementation in radiation oncology is a controversial issue. The German Working Group
Trace Elements and
Electrolytes in Oncology (AKTE) has conducted a number of studies on this issue, which are summarized in this review. Strategies have been tested and developed, aiming to stratify the patients with a potential need for supplemental Se and how best to monitor Se supplementation with respect to health effects and risks. Methods: We analyzed blood and tissue Se-levels of different
tumor patients (n = 512). Two randomized phase III clinical studies were conducted for testing a potential radioprotective effect of supplemental Se during
radiation therapy in patients with
uterine cancer (n = 81) and head and neck
tumor patients (n = 39). Results: A relative Se deficit in whole blood or serum was detected in the majority of
tumor patients (
carcinomas of the uterus, head and neck, lung, rectal or
prostate cancer). In
prostate cancer, tissue Se concentrations were relatively elevated in the
carcinoma centre as compared to the surrounding compartment or as compared to
tumor samples from patients with
benign prostatic hyperplasia. Adjuvant Se supplementation successfully corrected Se-deficiency in the patients analyzed and decreased
radiotherapy-induced
diarrhea in a randomized study of
radiotherapy patients with
carcinomas of the uterus. Survival data imply that Se supplementation did not interfere with radiation success. Some positive effects of supplemental Se in the prevention of
ageusia (
loss of taste) and
dysphagia due to
radiotherapy were noted in a second randomized trial in patients with
head and neck cancer. We have not observed any adverse effects of supplemental Se in our studies. Conclusions: Se supplementation yielded promising results concerning radioprotection in
tumor patients and should be considered as a promising adjuvant treatment option in subjects with a relative Se deficit.