MAMMOGRAPHIC DENSITY AND BREAST CANCER RISK

描述：乳房X线摄影致密乳腺比例高的女性 乳腺癌的发病率会增加三到六倍。 在乳房X光片上看起来致密的乳房的百分比反映了 与脂肪相比，基质和上皮组织的比例不同， 在健康女性中， 在精心设计的研究中， 乳腺癌的风险与乳腺摄影密度增加有关 超过了大多数其他预测因素，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线摄影密度的理解， 评估内源性激素的血浆水平之间的关联， 生长因子、胰岛素、胆固醇、营养素和抗氧化剂， 乳腺密度和乳腺癌风险之间的关系。 这项研究得益于 前瞻性设计和广泛的信息可供受试者在 正在进行的血浆生物标志物和乳腺癌风险的病例对照研究 （CA 49449），嵌套在护士健康研究（CA 40356）中。 是 据估计，乳房X光检查信息和血浆生物标志物都将被 可用于690例病例和924例对照。 在这些病例和对照中， 这项研究将确定是否乳腺癌的风险与 乳房X线摄影密度由生长因子的血浆水平解释， 胰岛素胆固醇营养素和抗氧化剂 在233例和 466名绝经后未使用绝经后激素的对照者 在献血时，本研究旨在确定 与乳房X线摄影密度相关的乳腺癌风险部分 这可以通过内源性激素的血浆水平来解释。 评估 本研究将采用一种新开发的方法， 旨在通过乳房X线摄影确定乳房面积的百分比， 基于对数字化图像的纹理分析来确定密度， 间质和上皮组织之间的关系。 作为这项研究的一部分， 一个新的计算机化系统，以评估乳房X光检查的特点将比较， 评估乳房X线摄影密度百分比的现有技术：1）a 放射科医生对密度百分比进行目视评估; 2）测量 从密度的标记区域评估;和3）计算机辅助 从基于灰度的系统测量百分比密度。

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.