Goodman Marc T, Shvetsov Yurii B, Wilkens Lynne R, Franke Adrian A, Le Marchand Loic, Kakazu Kerry K, Nomura Abraham M Y, Henderson Brian E, Kolonel Laurence N
Etiology Program, Cancer Research Center of Hawaii, University of Hawaii, 1236 Lauhala Street, Honolulu, HI 96813, USA.
Cancer Prev Res (Phila). 2009 Oct;2(10):887-94. doi: 10.1158/1940-6207.CAPR-09-0039. Epub 2009 Sep 29.
The objective of this study was to examine the association of urinary phytoestrogens with the risk of postmenopausal breast cancer. Participants in the Multiethnic Cohort Study included 36,458 postmenopausal women who provided blood or urine specimens. A nested case-control study of breast cancer with biospecimens was created in which cases diagnosed after specimen collection were matched to two controls. Two hundred fifty-one women with breast cancer and 462 controls had urine available for analysis of urinary phytoestrogens. Odds ratios (OR) and 95% confidence intervals (CI) were obtained using conditional logistic regression. A nonmonotonic inverse trend (P = 0.04) in breast cancer risk was associated with increasing urinary excretion of genistein (OR 25th-75th percentile, 0.88; 95% CI, 0.78-0.99) and total isoflavones (OR 25th-75th percentile, 0.80; 95% CI, 0.65-0.99). A significant reduction in breast cancer risk in Japanese-American women was associated with the highest compared with the lowest quartile excretion of urinary daidzein (OR, 0.41; 95% CI, 0.19-0.89; P(trend), 0.005). The risk of breast cancer was reduced among White women with the highest compared with the lowest quartile excretion of equol (OR, 0.27; 95% CI, 0.08-0.95), although the trend in risk was not significant (P = 0.07). Our results provide some support to the hypothesis that a diet rich in isoflavones from soy products reduces the risk of postmenopausal breast cancer, particularly in populations with comparatively high excretion of phytoestrogens.
本研究的目的是检验尿中植物雌激素与绝经后乳腺癌风险之间的关联。多民族队列研究的参与者包括36458名绝经后女性，她们提供了血液或尿液样本。利用生物样本开展了一项乳腺癌巢式病例对照研究，其中在样本采集后诊断出的病例与两名对照进行匹配。251名乳腺癌女性和462名对照有尿液可用于分析尿中植物雌激素。使用条件逻辑回归获得比值比（OR）和95%置信区间（CI）。乳腺癌风险呈非单调反向趋势（P = 0.04），与染料木黄酮尿排泄量增加（OR第25至75百分位数，0.88；95%CI，0.78 - 0.99）和总异黄酮（OR第25至75百分位数，0.80；95%CI，0.65 - 0.99）相关。与尿黄豆苷元排泄量最低四分位数相比，尿黄豆苷元排泄量最高四分位数的日裔美国女性乳腺癌风险显著降低（OR，0.41；95%CI，0.19 - 0.89；P（趋势），0.005）。与雌马酚排泄量最低四分位数相比，雌马酚排泄量最高四分位数的白人女性乳腺癌风险降低（OR，0.27；95%CI，0.08 - 0.95），尽管风险趋势不显著（P = 0.07）。我们的结果为以下假设提供了一些支持，即富含大豆制品异黄酮的饮食可降低绝经后乳腺癌风险，尤其是在植物雌激素排泄量相对较高的人群中。
