Positive Health Online

Abstract

BAKKER and COLLEAGUES, 1. Julius Center for Health Sciences and Primary Care and m.f.bakker-8@umcutrecht.nl ; Full Listing available on request, evaluated the associations of plasma carotenoid, retinol, tocopherol, and vitamin C concentrations and risk of breast cancer.

Background

Carotenoids and vitamin C are thought to be associated with reduced cancer risk because of their antioxidative capacity.

Methodology

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 oestrogen receptor-negative (ER-) cases (n = 462). Controls (n = 1502) were individually matched to cases by using incidence density sampling. Prediagnostic samples were analyzed for α-carotene, β-carotene, lycopene, lutein, zeaxanthin, β-cryptoxanthin, retinol, α-tocopherol, γ-tocopherol, and 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, α-carotene (OR: 0.61; 95% CI: 0.39, 0.98) and β-carotene (OR: 0.41; 95% CI: 0.26, 0.65) were inversely associated with risk of ER- breast tumours. The other analytes were not statistically associated with ER- breast cancer. For oestrogen receptor-positive (ER+) tumours, no statistically significant associations were found. The test for heterogeneity between ER- and ER+ tumours was statistically significant only for β-carotene (P-heterogeneity = 0.03). A higher risk of breast cancer was found for retinol in relation to ER-/progesterone receptor-negative tumours (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 β-carotene and α-carotene are associated with lower breast cancer risk of ER- tumours.

References

Bakker MF1,et al... Plasma carotenoids, vitamin C, tocopherols, and retinol and the risk of breast cancer in the European Prospective Investigation into Cancer and Nutrition cohort. Am J Clin Nutr.103(2):454-64. Feb  2016.  doi: 10.3945/ajcn.114.101659. Epub Jan 20 2016.