Adolescent Dietary Pattern and Premenopausal Breast Cancer

描述(申请人提供)：成人饮食和乳腺癌已被广泛研究，但很少出现明确的联系。然而，成年期可能不是女性一生中饮食暴露影响乳腺癌发生或进展的最敏感时期。新出现的证据支持早期生活经历在形成乳腺癌风险方面的重要性，特别是在更年期之前。乳腺组织在青春期发育，但乳腺的末端结构直到第一次怀孕才分化。乳腺癌病因学的数学模型也表明，第一胎出生前的几年对于确定乳腺癌风险至关重要。然而，在收集有关早期生活和青少年饮食的相关数据方面的挑战限制了关于青少年饮食和乳腺癌风险的研究数量。了解饮食在乳腺癌病因中的作用是非常重要的，因为饮食是一个潜在的可改变的危险因素。饮食模式分析使我们能够将饮食作为一个整体进行检查，并超越考虑食物和营养素在疾病风险中的个体作用。我们建议在护士健康研究II中使用已经收集的关于青少年营养和绝经前乳腺癌发病率的数据。参与者在1998年完成了一份关于他们在高中期间饮食的食物频率问卷。饮食模式将使用因子分析和降阶回归来生成。我们建议使用COX比例风险模型进行前瞻性分析，以估计与每种饮食模式相关的乳腺癌发病率的风险比。我们的研究将限于绝经前的女性，因为绝经前和绝经后的乳腺癌具有不同的危险因素。我们的目的是确定青少年的饮食模式，并调查这些饮食模式是否与绝经前乳腺癌风险有关：“谨慎”(健康)模式导致较低的发病率，而“西方”模式则导致较高的绝经前乳腺癌发病率。此外，我们将研究与胰岛素抵抗和炎症标志物相关的青春期饮食模式的女性是否有更高的绝经前乳腺癌发病率。我们有一个独特的资源，因为我们的饮食数据是在乳腺癌诊断之前收集的，我们前瞻性地收集了许多重要协变量的数据，包括大量乳腺癌的已知危险因素。这项研究的结果可能会为预防策略提供参考，并将乳腺癌预防工作的重点转移到这一关键的敏感期。

DESCRIPTION (provided by applicant): Adult diet and breast cancer has been extensively studied but few clear associations have emerged. Yet adulthood may not be the most susceptible time period during a woman's life time for dietary exposures to affect breast cancer initiation or progression. Emerging evidence supports the importance of experiences during early life in shaping breast cancer risk, in particular, prior to menopause. Mammary tissue develops during adolescence but terminal structures of the mammary gland do not differentiate until the first pregnancy. Mathematical models of breast cancer etiology also demonstrate that the years before first birth are critical in establishing breast cancer risk. Challenges in collectng relevant data on early life and adolescent diet, however, have limited the number of studies on adolescent diet and breast cancer risk. Understanding the role of diet in the etiology of breast cancer is of great importance since diet is a potentially modifiable risk factor. Dietary pattern analyses allow us to examine diet as a whole and to move beyond considering the individual role of foods and nutrients in disease risk. We propose to use already collected data on adolescent nutrition and premenopausal breast cancer incidence in the Nurses' Health Study II. Participants completed a food frequency questionnaire about their diet during high school in 1998. Dietary patterns will be generated using factor analysis and reduced rank regression. We propose to conduct a prospective analysis using a Cox proportional hazards model to estimate hazard ratios of breast cancer incidence associated with each of the dietary patterns. We will restrict our study to premenopausal women since pre- and postmenopausal breast cancer have different risk factor profiles. Our aim is to identify adolescent dietary patterns and investigate whether these dietary patterns are related to premenopausal breast cancer risk: a "prudent" (healthy) pattern to a lower incidence and a "Western" pattern to a higher incidence of premenopausal breast cancer. Furthermore, we will examine whether women with an adolescent dietary pattern that is associated with markers of insulin resistance and inflammation have a higher incidence of estrogen-receptor negative premenopausal breast cancer. We have a unique resource available since our dietary data have been collected prior to breast cancer diagnosis and we have prospectively collected data on many important covariates, including a large number of known risk factors for breast cancer. The results of this study may inform prevention strategies and shift the focus of breast cancer prevention efforts to this critical perid of susceptibility.