Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
Breast Cancer Res Treat. 2018 Nov;172(2):487-496. doi: 10.1007/s10549-018-4916-6. Epub 2018 Aug 23.
Breast fibroglandular tissue (FGT), as visualized on a mammogram (mammographic density, MD), is one of the strongest known risk factors for breast cancer. FGT is also visible on breast MRI, and increased background parenchymal enhancement (BPE) in the FGT has been identified as potentially a major breast cancer risk factor. The aim of this exploratory study was to examine the biologic basis of BPE.
We examined the unaffected contra-lateral breast of 80 breast cancer patients undergoing a prophylactic mastectomy before any treatment other than surgery of their breast cancer. BPE was classified on the BI-RADS scale (minimal/mild/moderate/marked). Slides were stained for microvessel density (MVD), CD34 (another measure of endothelial density), glandular tissue within the FGT and VEGF. Spearman correlations were used to evaluate the associations between BPE and these pathologic variables.
In pre-menopausal patients, BPE was highly correlated with MVD, CD34 and glandular concentration within the FGT, and the pathologic variables were themselves highly correlated. The expression of VEGF was effectively confined to terminal duct lobular unit (TDLU) epithelium. The same relationships of the four pathologic variables with BPE were seen in post-menopausal patients, but the relationships were much weaker and not statistically significant.
The strong correlation of BPE and MVD together with the high correlation of MVD with glandular concentration seen in pre-menopausal patients indicates that increased breast cancer risk associated with BPE in pre-menopausal women is likely to result from its association with increased concentration of glandular tissue in the FGT. The effective confinement of VEGF expression to the TDLUs shows that the signal for MVD growth arises directly from the glandular tissue. Further studies are needed to understand the basis of BPE in post-menopausal women.
乳房纤维腺体组织（fibroglandular tissue，FGT）在乳房 X 光片中可见（乳腺密度，mammographic density，MD），是已知最强的乳腺癌风险因素之一。FGT 在乳房磁共振成像（MRI）中也可见，并且在 FGT 中增加的背景实质增强（background parenchymal enhancement，BPE）已被确定为潜在的主要乳腺癌风险因素。本探索性研究旨在探讨 BPE 的生物学基础。
我们检查了 80 名接受预防性乳房切除术的乳腺癌患者的未受影响的对侧乳房，这些患者在接受乳腺癌手术治疗之前未接受任何其他治疗。BPE 按 BI-RADS 分级（轻度/中度/重度）进行分类。对微血管密度（microvessel density，MVD）、CD34（内皮密度的另一种测量方法）、FGT 内的腺体组织和 VEGF 进行染色。使用 Spearman 相关分析评估 BPE 与这些病理变量之间的相关性。
在绝经前患者中，BPE 与 MVD、CD34 和 FGT 内腺体浓度高度相关，这些病理变量本身也高度相关。VEGF 的表达实际上仅限于终末导管小叶单位（terminal duct lobular unit，TDLU）上皮。绝经后患者中也观察到了四个病理变量与 BPE 的相同关系，但相关性较弱且无统计学意义。
在绝经前患者中，BPE 与 MVD 的强烈相关性以及 MVD 与腺体浓度的高度相关性表明，BPE 与绝经前妇女乳腺癌风险增加相关，可能是由于其与 FGT 中腺体组织浓度增加有关。VEGF 表达的有效限制在 TDLUs 表明 MVD 生长的信号直接来自于腺体组织。需要进一步研究来了解绝经后妇女 BPE 的基础。
