Department of Medicine, Mayo Clinic College of Medicine, Charlton 6-239, 200 First Street SW, Rochester, MN 55905, USA.
Breast Cancer Res Treat. 2012 Jan;131(1):267-75. doi: 10.1007/s10549-011-1727-4. Epub 2011 Aug 30.
Mammographic density is a strong risk factor for breast cancer but its underlying biology in healthy women is not well-defined. Using a novel collection of core biopsies from mammographically dense versus non-dense regions of the breasts of healthy women, we examined histologic and molecular differences between these two tissue types. Eligible participants were 40 + years, had a screening mammogram and no prior breast cancer or current endocrine therapy. Mammograms were used to identify dense and non-dense regions and ultrasound-guided core biopsies were performed to obtain tissue from these regions. Quantitative assessment of epithelium, stroma, and fat was performed on dense and non-dense cores. Molecular markers including Ki-67, estrogen receptor (ER) and progesterone receptor (PR) were also assessed for participants who had >0% epithelial area in both dense and non-dense tissue. Signed rank test was used to assess within woman differences in epithelium, stroma and fat between dense and non-dense tissue. Differences in molecular markers (Ki-67, ER, and PR) were analyzed using generalized linear models, adjusting for total epithelial area. Fifty-nine women, mean age 51 years (range: 40-82), were eligible for analyses. Dense tissue was comprised of greater mean areas of epithelium and stroma (1.1 and 9.2 mm(2) more, respectively) but less fat (6.0 mm(2) less) than non-dense tissue. There were no statistically significant differences in relative expression of Ki-67 (P = 0.82), ER (P = 0.09), or PR (P = 0.96) between dense and non-dense tissue. Consistent with prior reports, we found that mammographically dense areas of the breast differ histologically from non-dense areas, reflected in greater proportions of epithelium and stroma and lesser proportions of fat in the dense compared to non-dense breast tissue. Studies of both epithelial and stromal components are important in understanding the association between mammographic density and breast cancer risk.
乳腺密度是乳腺癌的一个重要危险因素，但健康女性乳腺中乳腺密度的潜在生物学机制尚不清楚。本研究使用一种新的方法，对健康女性乳腺的致密区和非致密区进行核心活检，以检测这两种组织类型之间的组织学和分子差异。符合条件的参与者年龄在 40 岁以上，进行了乳房 X 光筛查，没有乳腺癌病史或正在接受内分泌治疗。通过乳房 X 光检查来识别致密区和非致密区，并使用超声引导下的核心活检来获取这些区域的组织。对致密和非致密核心进行上皮、基质和脂肪的定量评估。还评估了在致密和非致密组织中上皮面积大于 0%的参与者的分子标志物，包括 Ki-67、雌激素受体 (ER) 和孕激素受体 (PR)。使用符号秩检验评估致密和非致密组织中女性体内上皮、基质和脂肪的差异。使用广义线性模型分析分子标志物 (Ki-67、ER 和 PR) 的差异，同时调整总上皮面积。59 名女性符合纳入标准，平均年龄 51 岁（范围：40-82 岁）。致密组织的上皮和基质面积分别大 1.1 和 9.2mm2，但脂肪面积小 6.0mm2。致密和非致密组织中 Ki-67（P = 0.82）、ER（P = 0.09）和 PR（P = 0.96）的相对表达无统计学差异。与先前的报告一致，我们发现乳房 X 光致密区域在组织学上与非致密区域不同，在致密乳腺组织中上皮和基质的比例较大，脂肪的比例较小。对上皮和基质成分的研究对于理解乳腺密度与乳腺癌风险之间的关系非常重要。
