Jeffreys M, Warren R, Highnam R, Davey Smith G
Centre for Public Health Research, Massey University - Wellington Campus, Private Box 756, Wellington, New Zealand.
Br J Cancer. 2008 Jan 15;98(1):210-6. doi: 10.1038/sj.bjc.6604122. Epub 2007 Dec 18.
We conducted a cross-sectional study nested within a prospective cohort of breast cancer risk factors and two novel measures of breast density volume among 590 women who had attended Glasgow University (1948-1968), replied to a postal questionnaire (2001) and attended breast screening in Scotland (1989-2002). Volumetric breast density was estimated using a fully automated computer programme applied to digitised film-screen mammograms, from medio-lateral oblique mammograms at the first-screening visit. This measured the proportion of the breast volume composed of dense (non-fatty) tissue (Standard Mammogram Form (SMF)%) and the absolute volume of this tissue (SMF volume, cm3). Median age at first screening was 54.1 years (range: 40.0-71.5), median SMF volume 70.25 cm3 (interquartile range: 51.0-103.0) and mean SMF% 26.3%, s.d.=8.0% (range: 12.7-58.8%). Age-adjusted logistic regression models showed a positive relationship between age at last menstrual period and SMF%, odds ratio (OR) per year later: 1.05 (95% confidence interval: 1.01-1.08, P=0.004). Number of pregnancies was inversely related to SMF volume, OR per extra pregnancy: 0.78 (0.70-0.86, P<0.001). There was a suggestion of a quadratic relationship between birthweight and SMF%, with lowest risks in women born under 2.5 and over 4 kg. Body mass index (BMI) at university (median age 19) and in 2001 (median age 62) were positively related to SMF volume, OR per extra kg m(-2) 1.21 (1.15-1.28) and 1.17 (1.09-1.26), respectively, and inversely related to SMF%, OR per extra kg m(-2) 0.83 (0.79-0.88) and 0.82 (0.76-0.88), respectively, P<0.001. Standard Mammogram Form% and absolute SMF volume are related to several, but not all, breast cancer risk factors. In particular, the positive relationship between BMI and SMF volume suggests that volume of dense breast tissue will be a useful marker in breast cancer studies.
我们在一项关于乳腺癌风险因素的前瞻性队列研究中进行了一项横断面研究，并对590名曾就读于格拉斯哥大学（1948 - 1968年）、回复了邮政调查问卷（2001年）且在苏格兰参加过乳腺筛查（1989 - 2002年）的女性，采用了两种新的乳腺密度体积测量方法。使用一个全自动计算机程序对数字化的胶片 - 屏片乳腺钼靶X线片进行分析，从首次筛查时的内外侧斜位乳腺钼靶X线片来估计乳腺体积密度。该程序测量了由致密（非脂肪）组织构成的乳腺体积比例（标准乳腺钼靶形态（SMF）%）以及该组织的绝对体积（SMF体积，cm³）。首次筛查时的中位年龄为54.1岁（范围：40.0 - 71.5岁），中位SMF体积为70.25 cm³（四分位间距：51.0 - 103.0），平均SMF%为26.3%，标准差 = 8.0%（范围：12.7 - 58.8%）。年龄调整后的逻辑回归模型显示，末次月经年龄与SMF%之间呈正相关，每增加一岁的优势比（OR）为：1.05（95%置信区间：1.01 - 1.08，P = 0.004）。怀孕次数与SMF体积呈负相关，每多一次怀孕的OR为：0.78（0.70 - 0.86，P < 0.001）。出生体重与SMF%之间存在二次关系的迹象，出生体重低于及高于4 kg的女性风险最低。大学时期（中位年龄19岁）和2001年（中位年龄62岁）的体重指数（BMI）与SMF体积呈正相关，每增加一kg/m²的OR分别为1.21（1.15 - 1.28）和1.17（1.09 - 1.26），与SMF%呈负相关，每增加一kg/m²的OR分别为0.83（0.79 - 0.88）和0.82（0.76 - 0.88），P < 0.001。标准乳腺钼靶形态%和绝对SMF体积与多种但并非所有的乳腺癌风险因素相关。特别是，BMI与SMF体积之间的正相关表明，致密乳腺组织的体积将是乳腺癌研究中的一个有用标志物。
