FULL PROJECT #2

乳腺癌是美国女性中最常被诊断出的癌症， 癌症死亡的第二大原因(Ries等人，2010年)。美国目前的乳腺癌发病率 美国在高加索人中的比例高于非裔美国人。然而，乳腺癌死亡率 非裔美国人的比例高于高加索人，这可能是由于非洲人的倾向。 美国妇女被诊断为比高加索妇女更具侵袭性的疾病(Ries等人，2010年)。 在高加索妇女中确定的一些导致乳腺癌的环境危险因素(例如， 初潮、更年期晚、缺乏体力活动)在非裔美国人中的作用似乎不同 妇女(Bernstein等人，2003年)。很少有乳腺癌的遗传学研究包括足够数量的 非裔美国女性确定遗传风险因素或遗传和 高加索女性和非裔美国女性患乳腺癌的环境危险因素相似 (Jones等人，2004年)。人们对乳腺癌的病因知之甚少，也不知道是什么基因和 环境因素可能有助于解释乳腺癌发病率和死亡率的种族差异。

Breast cancer, the most commonly diagnosed cancer among women in the United States, is the second leading cause of cancer death (Ries et al., 2010). Current breast cancer incidence rates in the United States are higher among Caucasians than among African Americans. However, breast cancer mortality rates are higher among African Americans than among Caucasians, perhaps due to the tendency of African American women to be diagnosed with more aggressive disease than Caucasian women (Ries et al., 2010). Some ofthe environmental risk factors for breast cancer identified among Caucasian women (e.g., eariy age at menarche, late age at menopause, lack of physical activity) appear to operate differently in African American women (Bernstein et al., 2003). Few genetic studies of breast cancer have included a sufficient number of African American women to determine whether genetic risk factors or the interaction of genetic and environmental risk factors for breast cancer operate similariy in Caucasian and African American women (Jones et al., 2004). Little is understood about the etiology of breast cancer nor do we know what genetic and environmental factors might help explain racial disparities in breast cancer incidence and mortality.