Dietary selenium intake and thyroid cancer risk in postmenopausal women

Menée à partir de données 1993-1998 portant sur 147 348 femmes ménopausées (âge : 50-79 ans ; durée moyenne de suivi : 16,4 ans), cette étude analyse l'association entre l'apport en sélénium (alimentation et supplémentation) et le risque de cancer de la thyroïde (442 cas)

Résumé en anglais

Objective: Higher selenium intake and supplements have been suggested to protect against several cancers. Epidemiological evidence is rare and inconsistent on the association of selenium level and the risk of thyroid cancer. This study aimed to examine the association between selenium intake and thyroid cancer risk in postmenopausal women using the Women's Health Initiative (WHI) database.

Research Methods & Procedures: WHI study recruited 161,808 postmenopausal women aged 50-79 between September 1, 1993 and December 31, 1998. Our study included 147,348 women aged 63.15 (SD =7.21) years at baseline. The main exposure was baseline total selenium intake including dietary selenium measured by food frequency questionnaire (FFQ) and supplemental selenium. The outcome was thyroid cancer, which was adjudicated by trained physicians. Cox proportional hazard models were used to analyze the association.

Results: During a mean follow-up of 16.4 years until September 30, 2020, 442 thyroid cancer cases were identified. There was no significant association between total selenium intake and thyroid cancer risk after adjusting for multiple covariates (highest vs. lowest quartile: HR = 0.88, 95%CI: 0.60-1.29). Association between total selenium intake and the risk of papillary thyroid cancer was also not significant (highest vs. lowest quartile: HR = 1.02, 95%CI: 0.66-1.52).

Conclusion: Our data did not support that total or dietary selenium intake were associated with the risk of thyroid cancer or the papillary subtype in postmenopausal women aged 50-79 in the United States.