Division of General Internal Medicine, Department of Medicine, Institute for Human Genetics, University of California, San Francisco, California, USA.
Cancer Epidemiol Biomarkers Prev. 2010 Apr;19(4):1074-82. doi: 10.1158/1055-9965.EPI-09-1193. Epub 2010 Mar 23.
The incidence of breast cancer is 35% lower in Hispanic women living in the San Francisco Bay Area than in non-Hispanic White women. We have previously described a significant association between genetic ancestry and risk for breast cancer in a sample of U.S. Hispanics/Latinas. We retested the association in women residing in Mexico because of the possibility that the original finding may be confounded by U.S. specific unmeasured environmental exposures. We genotyped a set of 106 ancestry informative markers in 846 Mexican women with breast cancer and 1,035 unaffected controls and estimated genetic ancestry using a maximum likelihood method. Odds ratios and 95% confidence intervals (95% CI) for ancestry modeled as a categorical and continuous variable were estimated using logistic regression and adjusted for reproductive and other known risk factors. Greater European ancestry was associated with increased breast cancer risk in this new and independent sample of Mexican women residing in Mexico. Compared with women with 0% to 25% European ancestry, the risk was increased for women with 51% to 75% and 76% to 100% European ancestry [odds ratios, 1.35 (95% CI, 0.96-1.91) and 2.44 (95% CI, 0.94-6.35), respectively; P for trend = 0.044]. For every 25% increase in European ancestry (modeled as a continuous variable), there was a 20% increase in risk for breast cancer (95% CI, 1.03-1.41; P = 0.019). These results suggest that nongenetic factors play a crucial role in explaining the difference in breast cancer incidence between Latinas and non-Latina White women, and it also points out to the possibility of a genetic component to this difference.
居住在旧金山湾区的西班牙裔女性乳腺癌发病率比非西班牙裔白人女性低 35%。我们之前曾在一项美国西班牙裔/拉丁裔样本中描述了遗传背景与乳腺癌风险之间的显著关联。由于最初的发现可能受到美国特定未测量环境暴露的混杂，我们对居住在墨西哥的女性重新测试了这种关联。我们在 846 名患有乳腺癌的墨西哥女性和 1035 名未受影响的对照者中检测了 106 个遗传背景信息标记，并使用最大似然法估计了遗传背景。使用逻辑回归对作为分类和连续变量的遗传背景进行了模型构建，然后对其进行了调整，以校正生殖和其他已知风险因素。在这个新的和独立的居住在墨西哥的墨西哥女性样本中，更多的欧洲血统与乳腺癌风险增加有关。与具有 0%至 25%欧洲血统的女性相比，具有 51%至 75%和 76%至 100%欧洲血统的女性的患病风险增加[比值比（ORs）分别为 1.35（95%置信区间（CI），0.96-1.91）和 2.44（95% CI，0.94-6.35）；P 趋势=0.044]。每增加 25%的欧洲血统（作为连续变量建模），乳腺癌风险增加 20%（95%CI，1.03-1.41；P=0.019）。这些结果表明，非遗传因素在解释拉丁裔和非拉丁裔白人女性之间乳腺癌发病率差异方面起着至关重要的作用，并且也指出了这种差异存在遗传成分的可能性。
