Boyd N F, Lockwood G A, Byng J W, Little L E, Yaffe M J, Tritchler D L
Division of Epidemiology and Statistics, Ontario Cancer Institute, Toronto, Canada.
Br J Cancer. 1998 Nov;78(9):1233-8. doi: 10.1038/bjc.1998.660.
We studied 273 premenopausal women recruited from mammography units who had different degrees of density of the breast parenchyma on mammography, in whom we measured height, weight and skinfold thicknesses. Mammograms were digitized to high spatial resolution by a scanning densitometer and images analysed to measure the area of dense tissue and the total area of the breast. Per cent density and the area of non-dense tissue were calculated from these measurements. We found that the mammographic measures had different associations with body size. Weight and the Quetelet index of obesity were strongly and positively associated with the area of non-dense tissue and with the total area of the breast, but less strongly and negatively correlated with the area of dense tissue. We also found a strong inverse relationship between the areas of radiologically dense and non-dense breast tissue. Statistical models containing anthropometric variables explained up to 8% of the variance in dense area, but explained up to 49% of the variance in non-dense area and 43% of variance in total area. These results suggest that aetiological studies in breast cancer that use mammographic density should consider dense and non-dense tissues separately. In addition to per cent density, methods should be examined that combine information from these two tissues.
我们研究了从乳腺摄影单位招募的273名绝经前女性,她们在乳腺摄影中乳腺实质密度程度不同,我们测量了她们的身高、体重和皮褶厚度。通过扫描密度计将乳腺X线照片数字化至高空间分辨率,并对图像进行分析以测量致密组织面积和乳房总面积。根据这些测量结果计算出密度百分比和非致密组织面积。我们发现乳腺摄影测量结果与体型有不同的关联。体重和肥胖的克托莱指数与非致密组织面积和乳房总面积呈强烈正相关,但与致密组织面积的相关性较弱且呈负相关。我们还发现放射学致密和非致密乳腺组织面积之间存在强烈的负相关关系。包含人体测量变量的统计模型解释了致密面积方差的8%,但解释了非致密面积方差的49%和总面积方差的43%。这些结果表明,在使用乳腺摄影密度的乳腺癌病因学研究中,应分别考虑致密和非致密组织。除了密度百分比外,还应研究结合这两种组织信息的方法。