Department of Pathology, School of Medicine, Fatih University, 06540 Emek, Ankara, Turkey.
Pathol Res Pract. 2011 Mar 15;207(3):156-60. doi: 10.1016/j.prp.2010.12.005. Epub 2011 Feb 1.
Cytokeratin 7 (CK7) and cytokeratin 20 (CK20) are low molecular weight cytokeratins. The expressions of CK7 and CK20 have been studied in various primary and metastatic carcinomas. Their expression patterns may help to distinguish the site of origin of metastatic carcinomas. We investigated the expressions of CK7 and CK20 in 196 cases of colorectal carcinoma. Paraffin sections of 196 colonic adenocarcinomas were randomly selected, retrieved, and immunostained for CK7 and CK20 with a standard avidin-biotin complex method. CK7 was expressed in 34/196 (17.3%) and CK20 in 159/196 (81.1) cases of colorectal adenocarcinoma. CK7-/CK20+ had the greatest proportion (65.8%) in colorectal carcinomas. The CK7+/CK20+ immunophenotype was identified in 30/196 (15.3%), CK7-/CK20- in 33/196 (16.9%), and CK7+/CK20- in 4/196 (2%) colon adenocarcinomas. The CK7 and CK20 expression patterns were different in colorectal carcinomas according to histological grade, location of the tumor, and lymph node metastasis. CK20 positivity was more common in low grade carcinomas than in high grade carcinomas (85.1% versus 47.6%) and in rectal and sigmoid carcinomas than in proximal colon carcinomas (88.2% versus 63.2% and 88.9% versus 63.2%, respectively). Furthermore, CK7 expression was more common in tumors with lymph node metastasis than in non-metastatic tumors (25.3% versus 11%). In conclusion, a considerable number of colorectal carcinomas showed reactivity to CK7 (17.3%) or no reactivity to CK20 (18.9%). Therefore, CK7 positivity or CK20 negativity does not rule out a colorectal origin of metastatic carcinoma.
细胞角蛋白 7（CK7）和细胞角蛋白 20（CK20）是低分子量细胞角蛋白。CK7 和 CK20 的表达已在各种原发性和转移性癌中进行了研究。它们的表达模式可能有助于区分转移性癌的起源部位。我们研究了 196 例结直肠癌中 CK7 和 CK20 的表达。随机选择 196 例结肠腺癌的石蜡切片，进行 CK7 和 CK20 的免疫组织化学染色，采用标准的亲和素-生物素复合物法。CK7 在 34/196（17.3%）例结直肠腺癌中表达，CK20 在 159/196（81.1%）例中表达。CK7-/CK20+在结直肠癌中占比最大（65.8%）。在 196 例结直肠腺癌中，CK7+/CK20+免疫表型占 30/196（15.3%），CK7-/CK20-占 33/196（16.9%），CK7+/CK20-占 4/196（2%）。根据组织学分级、肿瘤位置和淋巴结转移情况，CK7 和 CK20 的表达模式在结直肠癌中有所不同。CK20 在低级别癌中比高级别癌中更常见（85.1%比 47.6%），在直肠和乙状结肠癌中比在近端结肠癌中更常见（88.2%比 63.2%和 88.9%比 63.2%）。此外，CK7 表达在有淋巴结转移的肿瘤中比在无淋巴结转移的肿瘤中更常见（25.3%比 11%）。总之，相当数量的结直肠癌对 CK7 呈反应性（17.3%）或对 CK20 无反应性（18.9%）。因此，CK7 阳性或 CK20 阴性并不能排除转移性癌的结直肠起源。
