Serum 25-hydroxyvitamin D and risk of breast cancer: results of a large population-based case-control study in Mexican women
Cancer Causes and Control, 06/01/2012
Fedirko V et al. – The results of this large population–based case–control study indicate an inverse association between circulating vitamin D levels and breast cancer risk among pre– and postmenopausal Mexican women.Methods
- A population–based case–control study in Mexico with 1,000 incident breast cancer cases aged 35–69 years, enrolled shortly after diagnosis (0–6 days) and frequency–matched to 1,074 controls on age, region, and health care system, was used to assess the association between serum 25–hydroxyvitamin D [25(OH)D] levels with overall, pre– and postmenopausal breast cancer risk.
- 25(OH)D concentration was measured on a random sub–sample of women (573 cases and 639 matched controls) using a liquid chromatography/tandem mass spectrometry method.
- Odds ratios (ORs) and 95 % confidence intervals (CIs) were estimated from multivariable conditional logistic regression models.
- Serum 25(OH)D concentration (per 10 ng/mL increase) showed a strong inverse association with risk of breast cancer among all (p trend=0.001), pre– (p trend=0.006) and postmenopausal women (p trend=0.0001).
- Compared with a predefined lower concentration of 25(OH)D (<20 ng/mL), higher levels (>30 ng/mL) were associated with lower overall (OR=0.53, 95 % CI: 0.28–1.00; p trend = 0.002), pre– (OR=0.60, 95 % CI: 0.16–2.17; p trend=0.07) and postmenopausal (OR=0.37, 95 % CI: 0.16–0.82; p trend = 0.004) breast cancer risk.