El-Bastawissi A Y, White E, Mandelson M T, Taplin S H
Cancer Prevention Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109-1024, USA.
Cancer Causes Control. 2000 Dec;11(10):955-63. doi: 10.1023/a:1026514032085.
We determined the association of certain reproductive and hormonal factors with breast density over decades of life.
Subjects were women age 20-79 years who had a screening mammogram between 1 June 1996 and 1 August 1997, in Seattle, Washington. Women with increased breast density (upper two categories of BI-RADS terminology) (n = 14,432) were compared to those with fatty breasts (lower two categories (n = 14,552). Unconditional logistic regression was used with adjustment for age at mammogram, parity, age at first birth, menopausal status, current use of hormone replacement therapy (HRT), and body mass index.
The association of nulliparity with density was evident for women at all ages (odds ratio (OR) and 95% confidence interval (CI) = 1.5 (1.3-1.7) and 1.6 (1.4-1.9) for women age < or = 45 and > 65, respectively). Older age at first birth was more strongly associated with density among women > 55 than among younger women. The association of current use of HRT with density, but not of former use, increased with age when compared to never users (OR = 1.4 (1.2-1.7) and 2.2 (2.0-2.5) for women age 46-55 and > 65, respectively).
Results suggest that pregnancy at an early age has a permanent beneficial association with density, while HRT has a transitory adverse association.
我们确定了某些生殖和激素因素与数十年生命历程中乳腺密度的关联。
研究对象为1996年6月1日至1997年8月1日期间在华盛顿州西雅图进行乳腺筛查钼靶检查的20 - 79岁女性。将乳腺密度增加（BI - RADS术语的上两个类别）的女性（n = 14432）与脂肪型乳腺（下两个类别）的女性（n = 14552）进行比较。使用无条件逻辑回归，并对钼靶检查时的年龄、产次、初产年龄、绝经状态、当前激素替代疗法（HRT）的使用情况和体重指数进行调整。
未生育与乳腺密度的关联在各年龄段女性中均很明显（年龄≤45岁和＞65岁女性的优势比（OR）及95%置信区间（CI）分别为1.5（1.3 - 1.7）和1.6（1.4 - 1.9））。初产年龄较大与55岁以上女性的乳腺密度关联比年轻女性更强。与从未使用者相比，当前使用HRT与乳腺密度的关联随年龄增加而增加，但既往使用则不然（46 - 55岁和＞65岁女性的OR分别为1.4（1.2 - 1.7）和2.2（2.0 - 2.5））。
结果表明，早年怀孕与乳腺密度存在永久性有益关联，而HRT与乳腺密度存在短暂性不利关联。
