Breast Cancer, Breast Density & Admixture Among Latinas

描述（由申请人提供）：乳腺癌发病率在不同的种族和民族群体中差异很大。混合人群，即两个或两个以上的种族群体混合在一起，可以为这些差异的病因学提供见解。拉丁美洲人主要是欧洲人、美洲原住民和非洲祖先的混血儿。在加州，大多数拉丁美洲人是来自墨西哥和中美洲国家的移民，主要是欧洲和美洲原住民的祖先。拉丁美洲人的乳腺癌发病率大大低于白种人，但高于美洲原住民，这与他们的欧洲和美洲原住民混合血统一致。该项目将研究拉丁裔遗传祖先与乳腺癌风险之间的关系。利用一项针对湾区拉丁裔患者的病例对照研究，我们将比较240名患有乳腺癌的拉丁裔患者和300名年龄匹配的拉丁裔对照组的遗传血统。祖先将用一系列遗传标记来估计，这些标记对祖先的信息非常丰富。分析将根据已知的乳腺癌非遗传风险因素进行调整。我们也将检查乳房x线摄影密度和遗传血统之间的关系在拉丁美洲。乳房x光检查显示，乳腺密度是已知的乳腺癌最强烈的危险因素之一，也是一种高度遗传的特征。为了实现这一目标，我们将招募100名乳腺密度极高的拉丁裔妇女，并将这些妇女的遗传血统与100名乳腺密度极低的拉丁裔妇女进行比较。基于这些结果，我们将确定乳腺癌风险和乳房x线摄影密度的遗传关联研究是否可能与拉丁裔人群的血统相混淆。此外，该项目将测试利用混合人群中增加的连锁不平衡来确定与拉丁裔乳腺癌相关的遗传变异的可行性。

DESCRIPTION (provided by applicant): Breast cancer incidence rates vary widely among different racial and ethnic groups. Admixed populations, in which two or more ethnic groups have mixed, may provide insight into the etiology of these differences. Latino Americans are largely an admixed group descended from European, Native American, and African ancestors. In California, the majority of Latinos are immigrants from Mexico and Central American countries, and are mainly of European and Native American ancestry. Latinas have breast cancer incidence rates that are substantially lower than Caucasians but higher than Native Americans, consistent with their mixed European and Native American descent. This project will examine the association between genetic ancestry among Latinas and breast cancer risk. Using an established case-control study of Latinas in the Bay Area we will compare genetic ancestry among 240 Latinas with breast cancer and 300 age-matched Latina controls. Ancestry will be estimated with a series of genetic markers highly informative for ancestry. Analyses will be adjusted for known non-genetic risk factors for breast cancer. We will also examine the association between mammographic density and genetic ancestry among Latinas. Mammographic breast density is one of the strongest known risk factors for breast cancer and is a highly heritable trait. To address this aim we will recruit 100 Latina women with extremely high mammographic density and compare the genetic ancestry among these women with 100 Latina women with extremely low breast density. Based on these results we will determine whether genetic association studies of breast cancer risk and of mammographic density may be confounded by ancestry in the Latina population. In addition, this project will test the feasibility of using the increased linkage disequilibrium in admixed populations to identify genetic variations associated with breast cancer among Latinas.