Selenium and thyroid cancer: a systematic review
A partir d'une revue systématique de la littérature publiée jusqu'en juin 2018 (5 articles), cette étude analyse l'association entre les taux sanguin et tissulaire de sélénium et le risque de cancer de la thyroïde
The aim of the study was to investigate the association between blood and tissue levels of selenium and thyroid cancer through a systematic review. We searched for observational studies written in English, Spanish, and Portuguese indexed in PubMed, LILACS, and Scielo without date restriction, that evaluated the association between selenium levels in whole-blood, serum, or plasma and/or thyroid tissue and thyroid cancer, both in individuals with cancer of thyroid as in healthy individuals. Then data were extracted and analyzed. Of the 570 articles identified, five cross-sectional studies were included in the review. In one study, lower concentrations of selenium were found in whole-blood (0.543??g/ml) and in the thyroid (0.88??g/g) of thyroid cancer patients compared to controls. Another study showed a decrease in serum selenium concentrations in patients with follicular carcinoma and papillary types (0.077?±?0.021??g/ml and 0.080?±?0.020??g/ml, respectively). On the other hand, other studies showed no difference in plasma selenium content or glutathione peroxidase activity among patients and healthy volunteers. The available evidence on this issue is inconclusive. Additional studies are needed to elucidate the association between serum and/or tissue levels of selenium and the development of thyroid cancer.