Plasma carotenoids and the risk of premalignant breast disease in women aged 50 and younger: a nested case-control study.

PURPOSE: To examine the association of plasma carotenoids, micronutrients in fruits, and vegetables, with risk of premalignant breast disease (PBD) in younger women.

METHODS: Blood samples were collected at the Siteman Cancer Center between 2008 and 2012 from 3537 women aged 50 or younger with no history of cancer or PBD. The analysis included 147 participants diagnosed with benign breast disease or breast carcinoma in situ during a 27-month follow-up and 293 controls. Cases and controls were matched on age, race/ethnicity, and date of and fasting status at blood draw. Plasma carotenoids were quantified. We used logistic regression to calculate odds ratios (ORs) and 95% confidence intervals (CIs) and linear regression to assess racial differences in plasma carotenoids.

RESULTS: The risk reduction between the highest and lowest tertiles varied by carotenoid, with β-cryptoxanthin having the greatest reduction (OR 0.62; 95% CI, 0.62-1.09; P trend  = 0.056) and total carotenoids the least (OR 0.83; 95% CI, 0.48-1.44; P trend  = 0.12). We observed an inverse association between plasma carotenoids and risk of PBD in obese women (BMI ≥ 30 kg/m2 ; 61 cases and 115 controls) but not lean women (BMI < 25 kg/m2 ; 54 cases and 79 controls), although the interaction was not statistically significant. Compared to white women, black women had lower levels of α and β-carotene and higher levels of β-cryptoxanthin and lutein/zeaxanthin.

CONCLUSIONS: We observed suggestive inverse associations between plasma carotenoids and risk of PBD in younger women, consistent with inverse associations reported for invasive breast cancer. Carotenoids may play a role early in breast cancer development.