Lin Jennifer, Manson JoAnn E, Lee I-Min, Cook Nancy R, Buring Julie E, Zhang Shumin M
Division of Preventive Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02215, USA.
Arch Intern Med. 2007 May 28;167(10):1050-9. doi: 10.1001/archinte.167.10.1050.
Animal data suggest the potential anticarcinogenic effects of calcium and vitamin D on breast cancer development. However, epidemiologic data relating calcium and vitamin D levels to breast cancer have been inconclusive.
We prospectively evaluated total calcium and vitamin D intake in relation to breast cancer incidence among 10,578 premenopausal and 20,909 postmenopausal women 45 years or older who were free of cancer and cardiovascular disease at baseline in the Women's Health Study. Baseline dietary intake was assessed by a food frequency questionnaire. We used Cox proportional hazards regression to estimate hazard ratios and 95% confidence intervals.
During an average of 10 years of follow-up, 276 premenopausal and 743 postmenopausal women had a confirmed diagnosis of incident invasive breast cancer. Higher intakes of total calcium and vitamin D were moderately associated with a lower risk of premenopausal breast cancer; the hazard ratios in the group with the highest relative to the lowest quintile of intake were 0.61 (95% confidence interval, 0.40-0.92) for calcium (P = .04 for trend) and 0.65 (95% confidence interval, 0.42-1.00) for vitamin D intake (P = .07 for trend). The inverse association with both nutrients was also present for large or poorly differentiated breast tumors among premenopausal women (P< or =.04 for trend). By contrast, intakes of both nutrients were not inversely associated with the risk of breast cancer among postmenopausal women.
Findings from this study suggest that higher intakes of calcium and vitamin D may be associated with a lower risk of developing premenopausal breast cancer. The likely apparent protection in premenopausal women may be more pronounced for more aggressive breast tumors.
动物数据表明钙和维生素D对乳腺癌发展具有潜在的抗癌作用。然而，关于钙和维生素D水平与乳腺癌关系的流行病学数据尚无定论。
我们前瞻性评估了10578名绝经前和20909名45岁及以上绝经后女性的总钙和维生素D摄入量与乳腺癌发病率的关系，这些女性在女性健康研究基线时无癌症和心血管疾病。通过食物频率问卷评估基线饮食摄入量。我们使用Cox比例风险回归来估计风险比和95%置信区间。
在平均10年的随访期间，276名绝经前女性和743名绝经后女性被确诊为侵袭性乳腺癌。总钙和维生素D摄入量较高与绝经前乳腺癌风险较低适度相关；摄入量最高组相对于最低五分位数组的风险比，钙为0.61（95%置信区间，0.40 - 0.92）（趋势P = 0.04），维生素D摄入量为0.65（95%置信区间，0.42 - 1.00）（趋势P = 0.07）。绝经前女性中，对于大的或低分化乳腺癌，这两种营养素的反向关联也存在（趋势P≤0.04）。相比之下，这两种营养素的摄入量与绝经后女性乳腺癌风险均无反向关联。
本研究结果表明，较高的钙和维生素D摄入量可能与绝经前乳腺癌发病风险较低相关。绝经前女性中可能明显的保护作用，对于侵袭性更强的乳腺癌可能更显著。
