Dietary selenium intake and thyroid cancer risk in postmenopausal

Objective: It has been suggested that higher selenium intake and consumption of supplements protect against several cancers. To our knowledge, epidemiologic evidence is rare and inconsistent on the association of sele-nium level and the risk for thyroid cancer. Therefore, the aim of this study was to examine the association between selenium intake and thyroid cancer risk in postmenopausal women using the Women's Health Ini-tiative (WHI) database.Methods: The WHI recruited 161 808 postmenopausal women 50 to 79 y of age between September 1, 1993 and December 31, 1998. The present study included 147 348 women 63.15 y of age (SD = 7.21) at baseline. The main exposure was baseline total selenium intake including dietary selenium measured by food fre-quency questionnaire (FFQ) and supplemental selenium. The outcome was thyroid cancer, which was adjudi-cated by trained physicians. Cox proportional hazard models were used to analyze the association. Results: During a mean follow-up of 16.4 y until September 30, 2020, 442 thyroid cancer cases were identi-fied. There was no significant association between total selenium intake and thyroid cancer risk after adjust-ing for multiple covariates (highest versus lowest quartile: hazard ratio [HR], 0.88; 95% confidence interval [CI], 0.60-1.29). Association between total selenium intake and the risk for papillary thyroid cancer was also not significant (highest versus lowest quartile: HR, 1.02; 95% CI, 0.66-1.52).Conclusions: The present data did not support that either total or dietary selenium intake was associated with the risk for thyroid cancer or the papillary subtype in postmenopausal women ages 50 to 79 y in the United States.(c) 2022 Elsevier Inc. All rights reserved.

Automated summary

The study aimed to examine the association between selenium intake and thyroid cancer risk in postmenopausal women. The results showed no significant association between total selenium intake and thyroid cancer risk, as well as the risk for papillary thyroid cancer.