Abstract 884: Associations of intakes of magnesium and calcium and survival among women with breast cancer: Results from Western New York Exposures and Breast Cancer (WEB) Study

Abstract

Abstract Background: Magnesium (Mg) and calcium (Ca) antagonizes each other in (re)absorption, cell cycle regulation, inflammation, and many other physiologic activities. However, few studies have investigated the association between Mg and Ca intakes and breast cancer survival, and the interaction between Ca and Mg intake. Method: In a cohort of 1,170 women with primary, incident, and histologically confirmed breast cancer from Western New York State, we examined the relationship between intakes of these two minerals and survival. Cox regression models were used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI). Results: Mean follow-up time was 87.4 months after breast cancer diagnosis; there were 170 deaths identified. After adjustment for known prognostic factors, and intakes of energy, total vitamin D and total Ca, higher dietary intake of Mg was inversely associated with risk of all-cause mortality (HR = 0.50, 95% CI, 0.28-0.90 for highest vs. lowest tertile; p trend = 0.02). Likewise, a marginal association was found for total Mg intake from foods and supplements combined (HR = 0.58, 95% CI, 0.31-1.08; p trend = 0.09). The inverse association of higher total Mg intake with all-cause mortality was primarily presented among postmenopausal women and was stronger among women who had a high Ca:Mg intake ratio (>2.59). There were no clear associations for prognosis with intake of Ca. Conclusion: We found that Mg intake alone may improve overall survival following breast cancer, and the association may be stronger among those with high Ca:Mg intake ratio. Citation Format: Menghua Tao, Qi Dai, Amy E. Millen, Jing Nie, Stephen B. Edge, Maurizio Trevisan, Peter G. Shields, Jo Freudenheim. Associations of intakes of magnesium and calcium and survival among women with breast cancer: Results from Western New York Exposures and Breast Cancer (WEB) Study. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 884. doi:10.1158/1538-7445.AM2015-884