Khilko Natalya, Wang Jianmin, Wei Bing, Hicks David G, Tang Ping
Drexel University College of Medicine/Hahnemann University Hospital, Department of Pathology and Laboratory Medicine, Philadelphia, PA 19129.
Breast Cancer (Auckl). 2010 Oct 21;4:49-55. doi: 10.4137/BCBCR.S5037.
The expression of basal cytokeratin markers CK5/6 in breast carcinomas has been associated with high histological grade and poor clinical outcome. A previous study has shown that CK5/6 can be detected in up to 17% of invasive lobular carcinomas (ILC). Here we study the expression of three basal cytokeratin markers (CK5/6, CK14, and CK17) in 53 ILC cases diagnosed by histology and lack of E-cadherin expression. Among them, 42 were classic lobular carcinomas, 6 were tubular-lobular carcinoma, and 5 were pleomorphic lobular carcinomas. There was no significant difference among these three groups in patients' age, tumor size, uni- and multi-focality, expression of ER and PR, lymphovascular invasion, perineural invasion and lymph node metastasis. The only statistically different factor was HER2 over-expression, which was observed only in pleomorphic ILC (P = 0.0073). None of the 53 cases expressed CK5/6, CK14 or CK17; and 51/53 cases expressed luminal markers CK8 and CK18, and the two negative cases were both classic lobular carcinoma, with positivity for ER and PR. In conclusion, all 53 cases of ILC failed to show expression by any of the three basal CK markers, suggesting that very few ILC will demonstrate a basal phenotype when assessed by immunohistochemistry (IHC). More studies are needed to investigate molecular classification in lobular carcinoma of the breast.
乳腺癌中基底细胞角蛋白标志物CK5/6的表达与高组织学分级和不良临床预后相关。先前的一项研究表明，在高达17%的浸润性小叶癌（ILC）中可检测到CK5/6。在此，我们研究了53例经组织学诊断且E-钙黏蛋白表达缺失的ILC病例中三种基底细胞角蛋白标志物（CK5/6、CK14和CK17）的表达情况。其中，42例为经典小叶癌，6例为小管-小叶癌，5例为多形性小叶癌。这三组患者在年龄、肿瘤大小、单灶和多灶性、ER和PR表达、淋巴管浸润、神经周围浸润及淋巴结转移方面均无显著差异。唯一具有统计学差异的因素是HER2过表达，仅在多形性ILC中观察到（P = 0.0073）。53例病例中无一例表达CK5/6、CK14或CK17；53例中有51例表达管腔标志物CK8和CK18，2例阴性病例均为经典小叶癌，ER和PR呈阳性。总之，53例ILC病例均未显示三种基底CK标志物中的任何一种有表达，这表明通过免疫组织化学（IHC）评估时，极少有ILC会表现出基底表型。需要更多研究来探讨乳腺小叶癌的分子分类。
