Associations between dietary carotenoid intakes and breast cancer risk by estrogen receptor (ER) status remain unclear. We prospectively investigated these associations using a pooled analysis of the primary data from 16 cohort studies. During follow‐up of 996,735 women ranging from 6 to 22 years, 34,524 breast cancer cases (4,552 ER‐/19,722 ER+) were identified. We used Cox proportional hazards models to estimate study‐specific relative risks (RRs) and 95% confidence intervals (CIs) and pooled the estimates using a random‐effects model. In the preliminary analyses, comparing the highest and lowest quintiles of intake, beta‐carotene intake was associated with a 10% lower risk of ER‐ breast cancer (pooled multivariate RR = 0.89 (95% CI: 0.81–0.99), Ptrend = 0.07) but not with risk of ER+ breast cancer (pooled multivariate RR = 1.02 (95% CI: 0.97–1.08), Ptrend = 0.76, Ptest for common effects by ER status = 0.02). Similarly, lutein/zeaxanthin intake was associated with a 13% reduced risk of ER‐ breast cancer (pooled multivariate RR = 0.87 (95%CI: 0.79–0.96), P trend = 0.04) but not with risk of ER+ breast cancer (pooled multivariate RR = 0.99 (95%CI: 0.93–1.06), Ptrend = 0.33, Ptest for common effects by ER status = 0.03). Alpha‐carotene, beta‐cryptoxanthin and lycopene intakes were not associated with breast cancer risk regardless of ER status. We observed similar associations when we categorized carotenoid consumption using identical absolute intake cutpoints or modeled intakes as continuous variables. The associations between carotenoid intake and risk of ER‐ and ER+ breast cancer did not differ by alcohol consumption, smoking habits, or menopausal status (Ptest for interaction > 0.05). Beta‐carotene and lutein/zeaxanthin intakes appeared to be associated with a lower risk of ER‐breast cancer but not with risk of ER+ breast cancer.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):A116.

Copyright © January 7, 2010, American Association for Cancer Research
2010