Body size and breast cancer risk in a multiethnic population

在美国和其他西方国家，肥胖和体重增加是重大的公共健康问题，也是少数几个可能在一生中改变的乳腺癌风险因素之一。虽然许多流行病学研究报告了与各种体型指标的关系，但在非洲裔美国人和西班牙裔妇女中进行的少数几项研究得出了不一致和不确定的结果。我们建议利用1995-2003年在旧金山湾区进行的一项基于人群的大型病例对照研究的数据来评估与各种终身体型测量的相关性。年龄35-79岁的乳腺癌病例是通过大湾区癌症登记中心确定的，对照是通过随机数字拨号。通过对2258名患者(596名白人，543名非裔美国人和1119名西班牙裔)和2706名对照组(646名白人，598名非裔美国人，1462名拉美裔)进行面对面采访，收集了关于自我报告和测量的身体尺寸的信息。该项目的目的是评估绝经前和绝经后乳腺癌风险与成年和青春期静态和动态体型测量的相关性。通过Logistic回归，我们将估计与以下因素相关的多变量调整优势比：1)身高、体重、体重指数(BMI)在每个十年和参考年份；2)成年期和成人体重范围内不同时间段的体重增加；3)青春期的体型和相对体重；以及4)腰围和臀围，以及腰臀比作为体脂分布的衡量标准。最后，我们将进行分层分析，以评估其他因素的调整效果，包括激素替代治疗的使用、年龄、绝经时间、乳腺癌家族史以及雌激素和孕激素受体状态。我们还将评估体力活动和卡路里摄入量的潜在调节作用。值得注意的研究优势包括大样本量、研究人群的多种族构成、基于人群的研究设计、通过亲自采访和测量对终身体型测量的全面评估，以及关于其他潜在混杂风险因素的大量数据。这项研究将对更好地了解乳腺癌的病因，特别是在非裔美国人和西班牙裔等未被研究的人群中体型的作用做出重要贡献。

Obesity and weight gain are significant public health issues in the US and other Western countries, and are among the few breast cancer risk factors that are potentially modifiable throughout life. Although many epidemiologic studies have reported on associations with various body size measures, the few studies conducted in African-American and Hispanic women have produced inconsistent and inconclusive results. We propose to assess associations with a wide range of lifetime body size measures utilizing data from a large population-based case-control study conducted in the San Francisco Bay area from 1995-2003. Breast cancer cases aged 35-79 years were identified through the Greater Bay Area Cancer Registry, controls through random-digit dialing. Information on self-reported and measured body size was collected through in- person interviews for 2,258 cases (596 Whites, 543 African-Americans, and 1,119 Hispanics) and 2,706 controls (646 Whites, 598 African-Americans, 1,462 Hispanics). The aims of this project are to assess associations of premenopausal and postmenopausal breast cancer risk with both static and dynamic measures of body size during adulthood and adolescence. Using logistic regression, we will estimate multivariate adjusted odds ratios associated with 1) height, weight, body mass index (BMI) in each decade of life and during the reference year; 2) weight gain at different time periods in adulthood and adult weight range; 3) body shape and comparative weight in adolescence; and 4) waist and hip circumferences, and waist-to-hip ratio as measures of body fat distribution. Lastly, we will perform stratified analyses to assess the modifying effects of other factors, including use of hormone replacement therapy, age, time since menopause, family history of breast cancer, and estrogen and progesterone receptor status. We will also assess the potentially modifying effects of physical activity and caloric intake. Notable study strengths include the large sample size, multiethnic composition of study population, population-based study design, comprehensive assessment of lifetime body size measures through in-person interviews and measurements, and extensive data on other potentially confounding risk factors. This study will make an important contribution towards a better understanding of breast cancer etiology, and the role of body size in particular, in understudied populations such as African-Americans and Hispanics.