Wang Ying, Gapstur Susan M, Gaudet Mia M, Peterson Julia J, Dwyer Johanna T, McCullough Marjorie L
Epidemiology Research Program, American Cancer Society, Atlanta, GA; and
Epidemiology Research Program, American Cancer Society, Atlanta, GA; and.
J Nutr. 2014 Oct;144(10):1603-11. doi: 10.3945/jn.114.196964. Epub 2014 Aug 20.
Results from preclinical studies suggest that flavonoids, which are ubiquitous in plant-based diets, lower breast cancer risk. Epidemiologic studies of flavonoid intake and breast cancer risk, however, are limited, and few investigated associations with the more aggressive estrogen receptor (ER)-negative (ER-) tumors.
We examined the associations between 7 subclasses of dietary flavonoids and invasive postmenopausal breast cancer risk overall and by ER status in a U.S. prospective cohort.
In 1999-2000, 56,630 postmenopausal women completed detailed self-administered questionnaires, among whom 2116 invasive breast cancers were verified during a mean follow-up period of 8.5 y. Cox proportional hazards regression was used to calculate multivariable-adjusted HRs and 95% CIs.
Total flavonoid intake was not associated with breast cancer risk. However, there was a modest inverse association between flavone intake and overall breast cancer risk (fifth vs. first quintile HR: 0.88; 95% CI: 0.76, 1.01; P-trend = 0.04) and between flavan-3-ol intake and risk of ER- breast cancer (for an increment of 40 mg/d; HR: 0.81; 95% CI: 0.67, 0.97) but not for ER-positive (ER+) breast cancer risk.
The inverse association of flavan-3-ol intake with ER- but not ER+ breast cancer is consistent with other studies that suggest a beneficial role of plant-based diets in ER- breast cancer risk.
临床前研究结果表明，在以植物为基础的饮食中普遍存在的类黄酮可降低乳腺癌风险。然而，关于类黄酮摄入量与乳腺癌风险的流行病学研究有限，很少有研究调查与侵袭性更强的雌激素受体（ER）阴性（ER-）肿瘤的关联。
我们在美国一项前瞻性队列研究中，研究了7种类黄酮亚类与绝经后浸润性乳腺癌总体风险以及按ER状态划分的风险之间的关联。
1999年至2000年，56630名绝经后女性完成了详细的自填问卷，其中2116例浸润性乳腺癌在平均8.5年的随访期内得到确诊。采用Cox比例风险回归计算多变量调整后的HR和95%CI。
总类黄酮摄入量与乳腺癌风险无关。然而，黄酮摄入量与总体乳腺癌风险之间存在适度的负相关（第五分位数与第一分位数相比，HR：0.88；95%CI：0.76，1.01；P趋势=0.04），黄烷-3-醇摄入量与ER-乳腺癌风险之间也存在负相关（每增加40mg/d；HR：0.81；95%CI：0.67，0.97），但与ER阳性（ER+）乳腺癌风险无关。
黄烷-3-醇摄入量与ER-乳腺癌而非ER+乳腺癌的负相关与其他研究一致，这些研究表明以植物为基础的饮食对ER-乳腺癌风险具有有益作用。
