早期胃癌组织中上皮钙粘蛋白表达与淋巴结微转移及临床病理的关系

Expression of Epithelial Cadherin in Early Gastric Cancer and Its Correlation to Lymph Node Micrometastasis and Clinicopathologic Features

背景与目的:早期胃癌淋巴结微转移问题日益受到关注,胞浆角蛋白(cytokeratin,CK)染色是识别上皮源性恶性肿瘤细胞的重要方法,本研究拟探讨早期胃癌原发灶上皮钙粘蛋白(epithelial cadherin,E-cad)的表达情况与淋巴结内出现微转移之间的关系及临床意义。方法:用免疫组织化学染色的方法对162例早期胃癌患者的4522枚淋巴结进行苏木精-伊红(HE)和胞浆角蛋白(cytokeratin,CK)染色,并对其中135例患者的原发灶切片进行E-cad染色,结合临床病理资料和随访结果进行分析。结果:HE染色发现的淋巴结转移率为6.8%(11/162),而CK染色发现的淋巴结转移率为26.5%(43/162),二者差异有统计学意义(P<0.001)。在151例HE染色未见淋巴结转移的患者中通过CK染色发现了32例(21.2%)有淋巴结微转移,且淋巴结微转移多见于原发灶直径大于1.0cm,组织分化不良,肿瘤浸润较深的(如浸及粘膜下层),淋巴管和血管受累,以及E-cad低表达标本(P<0.05)。原发灶E-cad的低表达率为57.0%(77/135),与淋巴结出现微转移有密切关系,有淋巴结微转移患者的5年生存率比没有微转移者明显低(P<0.01)。结论:肿瘤直径大于1.0cm,组织分化不良,较深的浸润,淋巴管或血管受累,以及E-cad低表达是早期胃癌患者出现淋巴结转移的高危因素。

BACKGROUND ＆ OBJECTIVE： Lymph node micrometastasis in early gastric cancer is being widely discussed. Cytokeratin （CK） staining is an important way to distinguish epithelial cancer cells. This study was to investigate the correlations of epithelial cadherin （E-cad） expression to lymph node micrometastasis, and clinicopathologic features of early gastric cancer, and to evaluate its clinical significance. METHODS： Morphology of 4522 lymph nodes from 162 patients with early gastric cancer was observed with HE staining and CK immunostaining. E-cad expression in 135 primary lesions of these patients was detected by immunohistochemistry. The correlations of E-cad expression to clinicopathologic features were analyzed. RUSULTS. The detection rate of lymph node metastasis by CK staining was significantly higher than that by HE staining （26.5% vs. 6.8%, P〈0.001）. CK immunostaining detected 32 cases of lymph node micrometastasis which were missed by HE staining. Lymph node micrometastasis was frequently found in primary tumors with a diameter of more than 1.0 cm, in those that were poorly differentiated, deeply invaded （for example, to the submucosa）, showed lymphatic or vascular invasion, and in those that showed loss of E-cad expression （P〈 0.05）. The reduced expression rate of E-cad in primary tumor was 57.0%, closely correlated to lymph node micrometastasis. The 5-year survival rate was significantly lower in the patients with lymph node micrometastasis than in those without such metastasis （93.6% vs. 100%, P〈0.01）. CONCLUSION： Primary tumor more than 1.0 cm in diameter, poor differentiation, deep invasion, lymphatic or vascular invasion, and loss of E-cad expression are risk factors for lymph node metastasis in early gastric cancer.