Abstract 4829: Plasma coenzyme Q10 levels and postmenopausal breast cancer risk: The Multiethnic Cohort Study

Abstract

Abstract Background: Coenzyme Q10 (CoQ10) is a component of the mitochondrial electron transport chain and is considered an important cellular antioxidant. Lower circulating CoQ10 levels are reported in patients with breast cancer, but epidemiologic evidence from large prospective studies is lacking. We examined the association of plasma CoQ10 levels with postmenopausal breast cancer risk in prospectively collected blood samples. Methods: Plasma levels of total CoQ10 were measured by HPLC with UV detection after precolumn coulometric oxidation among 160 incident postmenopausal breast cancer cases and 289 controls in the Multiethnic Cohort Study. Cases and controls were individually-matched on age, sex, ethnicity, study location (Hawaii or California), hormone replacement therapy use, date/time of collection and hours of fasting. Conditional logistic regression was used to compute odds ratios (ORs) and 95% confidence intervals (CIs). Results: Plasma CoQ10 levels were positively associated with breast cancer risk among postmenopausal women in the current study. The OR for the highest versus the lowest tertile was 1.6 (95% CI: 1.0 - 2.6; P = 0.05). The strongest association was observed for postmenopausal women under age 60 (OR for the highest versus the lowest tertile: 3.9; 95% CI: 1.1 - 14.0). Results were similar after adjusting for breast cancer risk factors. Conclusions: Higher CoQ10 levels in postmenopausal women are associated with increased breast cancer risk in this multiethnic population. Future studies are needed to define the origin of circulating CoQ10, its physiological meaning, and potential role in cancer etiology and progression. This work was supported by NIH Grants CA132149, CA33619. One of the authors (WC) was supported by NIH Training Grant CA90956. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4829.