@article{3169112,
    title = "Plasma carotenoids, vitamin C, tocopherols, and retinol and the risk of
breast cancer in the European Prospective Investigation into Cancer and
Nutrition cohort",
    author = "Bakker, Marije F. and Peeters, Petra H. M. and Klaasen, Veronique M. and and Bueno-de-Mesquita, H. Bas and Jansen, Eugene H. J. M. and Ros, Martine and M. and Travier, Noemie and Olsen, Anja and Tjonneland, Anne and Overvad, and Kim and Rinaldi, Sabina and Romieu, Isabelle and Brennan, Paul and and Boutron-Ruault, Marie-Christine and Perquier, Florence and Cadeau, and Claire and Boeing, Heiner and Aleksandrova, Krasimira and Kaaks, Rudolf and and Kuehn, Tilman and Trichopoulou, Antonia and Lagiou, Pagona and and Trichopoulos, Dimitrios and Vineis, Paolo and Krogh, Vittorio and and Panico, Salvatore and Masala, Giovanna and Tumino, Rosario and and Weiderpass, Elisabete and Skeie, Guri and Lund, Eiliv and Ramon Quiros, and J. and Ardanaz, Eva and Navarro, Carmen and Amiano, Pilar and Sanchez, and Maria-Jose and Buckland, Genevieve and Ericson, Ulrika and Sonestedt, and Emily and Johansson, Matthias and Sund, Malin and Travis, Ruth C. and and Key, Timothy J. and Khaw, Kay-Tee and Wareham, Nick and Riboli, Elio and and van Gils, Carla H.",
    journal = "AMERICAN JOURNAL OF CLINICAL NUTRITION",
    year = "2016",
    volume = "103",
    number = "2",
    pages = "454-464",
    publisher = "Oxford University Press",
    issn = "0002-9165",
    doi = "10.3945/ajcn.114.101659",
    keywords = "breast cancer; EPIC; antioxidants; carotenoids; plasma",
    abstract = "Background: Carotenoids and vitamin C are thought to be associated with
reduced cancer risk because of their antioxidative capacity.
Objective: This study evaluated the associations of plasma carotenoid,
retinol, tocopherol, and vitamin C concentrations and risk of breast
cancer.
Design: In a nested case-control study within the European Prospective
Investigation into Cancer and Nutrition cohort, 1502 female incident
breast cancer cases were included, with an oversampling of premenopausal
(n = 582) and estrogen receptor-negative (ER-) cases (n = 462). Controls
(n = 1502) were individually matched to cases by using incidence density
sampling. Prediagnostic samples were analyzed for alpha-carotene,
beta-carotene, lycopene, lutein, zeaxanthin, beta-cryptoxanthin,
retinol, alpha-tocopherol, gamma-tocopherol, and 454 vitamin C. Breast
cancer risk was computed according to hormone receptor status and age at
diagnosis (proxy for menopausal status) by using conditional logistic
regression and was further stratified by smoking status, alcohol
consumption, and body mass index (BMI). All statistical tests were
2-sided.
Results: In quintile 5 compared with quintile 1, alpha-carotene (OR:
0.61; 95% CI: 0.39, 0.98) and beta-carotene (OR: 0.41; 95% CI: 0.26,
0.65) were inversely associated with risk of ER- breast tumors. The
other analytes were not statistically associated with ER- breast cancer.
For estrogen receptor-positive (ER+) tumors, no statistically
significant associations were found. The test for heterogeneity between
ER- and ER+ tumors was statistically significant only for beta-carotene
(P-heterogeneity = 0.03). A higher risk of breast cancer was found for
retinol in relation to ER-/progesterone receptor-negative tumors (OR:
2.37; 95% CI: 1.20, 4.67; P-heterogeneity with ER+/progesterone
receptor positive = 0.06). We observed no statistically significant
interaction between smoking, alcohol, or BMI and all investigated plasma
analytes (based on tertile distribution).
Conclusion: Our results indicate that higher concentrations of plasma
beta-carotene and alpha-carotene are associated with lower breast cancer
risk of ER tumors."
}