Department of Surgery, New York University Langone Medical Center, 160 E 34th St, New York, NY 10016, USA.
AJR Am J Roentgenol. 2012 Mar;198(3):W292-5. doi: 10.2214/AJR.10.6049.
Breast density is increasingly recognized as an independent risk factor for the development of breast cancer, because it has been shown to be associated with a four- to sixfold increase in a woman's risk of malignant breast disease. Increased breast density as identified on mammography is also known to decrease the diagnostic sensitivity of the examination, which is of great concern to women at increased risk for breast cancer. Dense tissue has generally been associated with younger age and premenopausal status, with the assumption that breast density gradually decreases after menopause. However, the actual proportion of older women with dense breasts is unknown. The purpose of this study was to examine the relationship between age and breast density, particularly focusing on postmenopausal women.
All screening mammograms completed at the New York University Langone Medical Center in 2008 were retrospectively reviewed. Analysis of variance and descriptive analyses were used to evaluate the relationship between patient age and breast density.
A total of 7007 screening mammograms were performed. The median age of our cohort was 57 years. Within each subgroup categorized by decade of age, there was a normal distribution among the categories of breast density. There was a significant inverse relationship between age and breast density (p < 0.001). Seventy-four percent of patients between 40 and 49 years old had dense breasts. This percentage decreased to 57% of women in their 50s. However, 44% of women in their 60s and 36% of women in their 70s had dense breasts as characterized on their screening mammograms.
In general, we found an inverse relationship between patient age and mammographic breast density. However, there were outliers at the extremes of age. A meaningful proportion of young women had predominantly fatty breasts and a subset of older women had extremely dense breasts. Increased density renders mammography a less sensitive tool for early detection. Breast density should be considered when evaluating the potential benefit of extended imaging for breast cancer screening, especially for women at increased risk for the disease.
乳腺密度越来越被认为是乳腺癌发展的一个独立危险因素，因为它与女性恶性乳腺疾病风险增加 4 至 6 倍有关。乳房 X 光摄影术识别出的乳腺密度增加也降低了检查的诊断敏感性，这对乳腺癌风险增加的女性来说非常重要。致密组织通常与年轻和绝经前状态有关，假设绝经后乳腺密度逐渐降低。然而，实际存在致密乳房的老年女性的比例尚不清楚。本研究的目的是研究年龄与乳腺密度之间的关系，特别是关注绝经后女性。
回顾性分析 2008 年在纽约大学朗格尼医学中心完成的所有筛查乳房 X 光片。使用方差分析和描述性分析评估患者年龄与乳腺密度之间的关系。
共进行了 7007 次筛查乳房 X 光检查。我们队列的中位年龄为 57 岁。在按年龄十年划分的每个亚组中，乳腺密度的类别呈正态分布。年龄与乳腺密度之间存在显著的负相关关系（p<0.001）。40 至 49 岁的患者中有 74%乳腺致密。这个百分比在 50 多岁的女性中下降到 57%。然而，60 多岁的女性中有 44%和 70 多岁的女性中有 36%的乳房 X 光检查表现为致密。
一般来说，我们发现患者年龄与乳房 X 光密度之间存在负相关关系。然而，在年龄极端的情况下存在异常值。相当一部分年轻女性的乳房主要是脂肪组织，而一部分老年女性的乳房则非常致密。密度增加使乳房 X 光摄影术成为早期检测的敏感性较低的工具。在评估扩展成像对乳腺癌筛查的潜在益处时，应考虑乳腺密度，特别是对于患有该病风险增加的女性。
