Andratschke Michaela, Hagedorn Hjalmar, Luebbers Christian W, Schmitt Baerbel, Lang Stephan, Zeidler Reinhard, Wollenberg Barbara
Department of Otorhinolaryngology, Head and Neck Surgery, Grosshadem Medical Center, Marchioninistrafie 15, 81377 Munich, Germany.
Anticancer Res. 2006 Jan-Feb;26(1A):153-8.
The epithelial cell adhesion molecule (EpCAM) is expressed in most normal epithelia, but is absent from squamous stratified epithelia. However, a de novo expression can be observed in squamous epithelia during carcinogenesis.
In order to evaluate EpCAM as a molecular marker to indicate borders of high risk for the development of local recurrences, its expression was examined in the marginal zone of malignancies. Specimens of squamous cell carcinoma of the head and neck (SCCHN), of the histologically tumor-free defined resection margin and of healthy epithelia of 20 patients were examined by RT-PCR in order to identify the expression of EpCAM in these three different areas. Additionally, immunohistochemistry was perfonned on biopsies from 10 patients in order to confirm these findings and to investigate a potential correlation between EpCAM expression and the degree of dysplasia.
By RT-PCR, high expression of EpCAM was found in the tumor. An inverse correlation was observed between EpCAM expression and the distance from the tumor, with no expression being detectable in healthy oral mucosa. In 70% of the cases, EpCAM was expressed in the marginal zone, which had been defined as tumor-free by routine histopathological assessment. Additional immunohistology revealed no correlation between EpCAM expression and the grade of dysplasia.
Our data provide evidence that EpCAM is restricted as a marker for redefining the real tumor margin by RT-PCR. To complement routine histology, immunohistochemical staining with EpCAM is limited due to its expression in hyperplastic tissue without dysplastic changes. Both observations limit the reliable use of EpCAM for the molecular definition of the critical tumor border and resection margins.
上皮细胞粘附分子（EpCAM）在大多数正常上皮中表达，但在鳞状分层上皮中不存在。然而，在癌变过程中可观察到鳞状上皮中出现从头表达。
为了评估EpCAM作为指示局部复发高风险边界的分子标志物，在恶性肿瘤的边缘区域检测其表达。通过逆转录聚合酶链反应（RT-PCR）检测了20例头颈部鳞状细胞癌（SCCHN）患者的肿瘤组织、组织学上无肿瘤的定义切除边缘组织以及健康上皮组织样本，以确定EpCAM在这三个不同区域的表达。此外，对10例患者的活检组织进行了免疫组织化学检测，以证实这些发现并研究EpCAM表达与发育异常程度之间的潜在相关性。
通过RT-PCR发现肿瘤中EpCAM高表达。观察到EpCAM表达与距肿瘤的距离呈负相关，在健康口腔黏膜中未检测到表达。在70%的病例中，EpCAM在常规组织病理学评估定义为无肿瘤的边缘区域表达。额外的免疫组织学显示EpCAM表达与发育异常分级之间无相关性。
我们的数据提供了证据，表明EpCAM作为通过RT-PCR重新定义真正肿瘤边缘的标志物受到限制。为补充常规组织学，由于EpCAM在无发育异常改变的增生组织中表达，其免疫组织化学染色受到限制。这两个观察结果限制了EpCAM在分子定义关键肿瘤边界和切除边缘方面的可靠应用。
