Interaction between current vitamin D supplementation and menopausal hormone therapy use on breast cancer risk: evidence from the E3N cohort

卷:102

Cadeau, Claire ; Fournier, Agnes ; Mesrine, Sylvie ; Clavel-Chapelon, Francoise ; Fagherazzi, Guy ; Boutron-Ruault, Marie-Christine

关键词: vitamin D;    calcitriol;    supplements;    estrogen;    menopausal hormone therapy;    MHT;    breast cancer;    menopause;    cohort;    prospective study;   

DOI  :  10.3945/ajcn.114.104323

学科分类：食品科学和技术

【 摘 要 】

Background: Experimental studies suggest protective effects of vitamin D on breast carcinogenesis, particularly on estrogen receptor-positive tumors. Epidemiologic data are less conclusive. Objective: Our objective was to investigate the association between postmenopausal breast cancer risk and current or past vitamin D supplementation overall and according to the use of menopausal hormone therapy (MHT). Design: Between 1995 and 2008, 2482 invasive breast cancer cases were diagnosed among 57,403 postmenopausal women from the E3N prospective cohort during 581,085 person-years. Vitamin D supplementation was assessed from biennially self-administered questionnaires sent in 1995, 2000, 2002, and 2005 and from medico-administrative data on drug reimbursements since 2004. Multivariable HRs for primary invasive breast cancer and 95% CIs were estimated by using Cox models. Results: A decreased postmenopausal breast cancer risk was associated with current (HR: 0.82; 95% CI: 0.69, 0.97) but not past (HR: 1.10; 95% CI: 0.92, 1.31) vitamin D supplementation (P-homogeneity = 0.02). The association with current vitamin D supplementation differed according to MHT use: ever users (HR: 0.74; 95% CI: 0.60, 0.90) and never users (HR: 1.13; 95% CI: 0.89, 1.56); P-homogeneity = 0.02. Conclusions: In this observational study, current vitamin D supplementation, mostly taken daily and combined with calcium, was associated with a decreased postmenopausal breast cancer risk in MHT users. These findings should be confirmed before considering vitamin D supplementation to partly balance the MET-associated increased breast cancer risk.