MAMMOGRAPHIC DENSITY AND BREAST CANCER RISK

描述：乳房X光检查致密的女性比例较高 组织患乳腺癌的风险增加了三到六倍。 乳房X光照片上显示致密的乳房百分比反映了 间质和上皮组织的比例与脂肪相比，并有所不同 在健康的女性中相当多。在精心设计的研究中， 与乳房X光摄影密度增加相关的乳腺癌风险 超过了大多数其他预测值，并且独立于 传统的乳腺癌危险因素。拟议的研究将扩大 目前对乳房X线摄影密度的认识，并首次 评估血浆内源性激素水平之间的关系， 生长因子、胰岛素、胆固醇、营养素和抗氧化剂 乳房X光照相密度与乳腺癌风险。这项研究得益于 为主题提供的前瞻性设计和广泛的信息 正在进行的血浆生物标志物与乳腺癌风险的病例对照研究 (CA49449)，嵌套在护士健康研究(CA40356)中。它是 估计乳房X光检查信息和血浆生物标记物都将是 可用于690例病例和924例对照。在这些病例和对照中 这项研究将确定乳腺癌风险是否与 乳房X光照相密度是由血浆中生长因子水平来解释的， 胰岛素、胆固醇、营养素和抗氧化剂。在233宗个案中， 466名绝经后和未使用绝经后激素的对照组 在献血时，这项研究旨在确定 与乳房摄影密度相关的乳腺癌风险部分是 用血浆内源性激素水平来解释。评估 这项研究将采用一种新开发的方法，即 旨在通过乳房X光检查来确定乳房面积的百分比 基于数字化图像的纹理分析的密度，捕获 间质组织与上皮组织之间的关系。作为这项研究的一部分， 评估乳房X光检查特征的新计算机化系统将与 现有的评估百分比乳房摄影密度的技术：1)a 放射科医生对百分比密度的目测评估；2)测量 从标记的密度区域进行评估；以及3)计算机辅助 从基于灰度级的系统中测量百分比密度。

DESCRIPTION: Women with a high proportion of mammographically dense breast tissue have a three to six-fold increased risk of developing breast cancer. The percent of the breast that appears dense on a mammogram reflects the proportion of stromal and epithelial tissue compared to fat, and varies considerably among healthy women. In well-designed studies, the magnitude of the breast cancer risk associated with increased mammographic density exceeded that of most other predictors, and was independent of the traditional breast cancer risk factors. The proposed study will expand the current understanding of mammographic density and for the first time evaluate the associations between plasma levels of endogenous hormones, growth factors, insulin, cholesterol, nutrients and antioxidants with mammographic density and breast cancer risk. This study benefits from the prospective design and extensive information available for the subjects in the ongoing case-control study of plasma biomarkers and breast cancer risk (CA49449), nested within the Nurse's Health Study (CA40356). It is estimated that both mammographic information and plasma biomarkers will be available for 690 cases and 924 controls. Among these cases and controls this study will determine if the breast cancer risk associated with mammographic density is explained by the plasma levels of growth factors, insulin, cholesterol, nutrients and antioxidants. Among the 233 cases and 466 controls who were postmenopausal and not using postmenopausal hormones at the time of the blood donation, this study is intended to determine if the breast cancer risk associated with mammographic density is partially explained by the plasma levels of endogenous hormones. To assess mammographic density this study will employ a newly developed method, which is designed to determine the percent of the breast area with mammographic density based on a texture analysis of the digitized image, capturing the relation between stromal and epithelial tissue. As part of this study, the new computerized system to assess mammographic features will be compared to the existing techniques of assessing percent mammographic density: 1) a visual assessment of percent density by a radiologist; 2) measured assessment from the marked area of density; and 3) a computer-assisted measure of percent density from a grey-scale based system.