Hilson Justin B, Schnitt Stuart J, Collins Laura C
Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
Am J Surg Pathol. 2009 Feb;33(2):227-32. doi: 10.1097/PAS.0b013e318180431d.
Recent molecular studies have indicated that ductal carcinoma in situ (DCIS)-associated myoepithelial cells (MECs) show differences from MECs in normal breast tissue. Such alterations may influence the progression of DCIS to invasive cancer. The purpose of this study was to investigate further phenotypic alterations in DCIS-associated MECs. Paraffin sections of 101 cases of DCIS (56 without and 45 with associated invasive carcinoma) were immunostained for 7 MEC markers: smooth muscle actin, smooth muscle myosin heavy chain (SMMHC), calponin, p63, cytokeratin (CK) 5/6, CD10, and p75. In each case, the distribution and intensity of staining for each marker in DCIS-associated MECs was compared with that in MECs surrounding normal ductal-lobular structures on the same slide. In 85 cases (84.2%), DCIS-associated MECs showed decreased expression of one or more MEC markers when compared with normal MECs. The proportion of cases that showed reduced expression was 76.5% for SMMHC, 34.0% for CD10, 30.2% for CK5/6, 17.4% for calponin, 12.6% for p63, 4.2% for p75, and 1% for smooth muscle actin. Reduced MEC expression of SMMHC was significantly more frequent in high grade than in non-high-grade DCIS (84.8% vs. 61.5% of cases, P=0.01). We conclude that DCIS-associated MECs show immunophenotypic differences from MECs surrounding normal mammary ductal-lobular structures. The biologic significance of this remains to be determined. However, these results indicate that the sensitivity of some MEC markers is lower in DCIS-associated MECs than in normal MECs. This observation should be taken into consideration when selecting MEC markers to help distinguish in situ from invasive breast carcinomas.
近期的分子研究表明，导管原位癌（DCIS）相关的肌上皮细胞（MECs）与正常乳腺组织中的MECs存在差异。这种改变可能会影响DCIS向浸润性癌的进展。本研究的目的是进一步探究DCIS相关MECs的表型改变。对101例DCIS（56例无相关浸润性癌，45例有相关浸润性癌）的石蜡切片进行7种MEC标志物免疫染色：平滑肌肌动蛋白、平滑肌肌球蛋白重链（SMMHC）、钙调蛋白、p63、细胞角蛋白（CK）5/6、CD10和p75。在每例中，将DCIS相关MECs中各标志物的染色分布和强度与同一张玻片上正常导管小叶结构周围的MECs进行比较。85例（84.2%）中，与正常MECs相比，DCIS相关MECs显示一种或多种MEC标志物表达降低。显示表达降低的病例比例分别为：SMMHC 76.5%、CD10 34.0%、CK5/6 30.2%、钙调蛋白17.4%、p63 12.6%、p75 4.2%、平滑肌肌动蛋白1%。SMMHC的MEC表达降低在高级别DCIS中比非高级别DCIS更常见（病例分别为84.8%和6&5%，P=0.01）。我们得出结论，DCIS相关MECs与正常乳腺导管小叶结构周围的MECs存在免疫表型差异。其生物学意义尚待确定。然而，这些结果表明，某些MEC标志物在DCIS相关MECs中的敏感性低于正常MECs。在选择MEC标志物以帮助区分乳腺原位癌和浸润性癌时，应考虑这一观察结果。
