早期黏膜下胃癌微转移和微浸润的临床意义

目的 探讨临床早期黏膜下胃癌的淋巴结微转移和原发灶微浸润的临床意义。方法 对79例早期黏膜下胃癌患者手术切除的1945个淋巴结及68例肿瘤原发灶分别进行连续超薄切片,并应用抗细胞角蛋白(CK)单克隆抗体(CAM5．2)进行免疫组化检测并结合临床病理学指标及患者预后进行综合分析研究。结果 常规HE染色时,淋巴结转移率为13％(10／79),而CK染色为34％(27／79)。早期黏膜下胃癌的微转移发生率为25％(17／69)。68例早期黏膜下胃癌患者中,微浸润的发生率为16％(11,／68)。淋巴结微转移分别多发于肿瘤直径大于2cm(43％),凹陷型(48％),淋巴管侵犯(73％)和深度黏膜下侵犯(53％)的肿瘤。微浸润多发于低分化癌(33％)和深度黏膜下侵犯(31％)的肿瘤。5年生存率在没有微转移的患者为100％,有微转移的患者为82％,有微浸润的患者为73％。结论 CK免疫组化检查在诊断微转移和微浸润上明显优于常规HE检查。淋巴结的微转移和原发灶的微浸润明显影响黏膜下胃癌患者预后。

Clinical significance of micrometastasis in lymph nodes and microinvasion in primary lesion in submucosal gastric cancer

Objective To clarify the clinicopathologic characteristics of micrometastasis in lymph nodes and microinvasion in primary lesion for the treatment options with regard to submucosal gastric cancer. Methods 1945 lymph nodes and 68 primary tumors resected from 79 patients with submucosal gastric cancer were examined. Two consecutive sections were prepared for simultaneous staining with HE and immunostaining with anticytokeratin antibody (CAM 5.2), respectively. Results The incidence of nodal involvement in 79 patients with submucosal gastric cancer was increased from 13% (10/79 patients) by HE staining to 34% (27/79 patients) by cytokeratin immunostaining. Micrometastasis in the lymph nodes were found in 17 of 69 patients (25%) with cancer-free nodes examined by HE staining. Microinvasion to the muscularis properia was found in 11 of 68 patients (16%) who were histologically diagnosed as submucosal gastric cancer. Survival analysis demonstrated a worse 5-year survival in the patients with micrometastasis in lymph nodes (82%) and with microinvasion to muscularis properia (73%). A higher incidence of nodal involvement was found in submucosal cancers of large size (>2 cm; 43%), a depressed type (48%), lymphatic invasion (73%), and deeper submucosal invasion (submucosal 3; 53%). A higher incidence of microinvasion was found with the diffused-type carcinoma (33%). Conclusions Cytokeratin immunostaining is useful for detecting micrometastasis and microinvasion in submucosal gastric cancer. Tumor size, microscopic type, lymphatic invasion, and the depth of submucosal invasion are strongly associated with lymph node involvement. Micrometastasis in lymph nodes and microinvasion in primary lesion indicate an unfavorable outcome of the patients with submucosal gastric cancer.