Ⅱ期直肠癌淋巴结微转移检测的临床意义

Clinical significance of lymph node micrometastases in stage Ⅱ rectal cancer patients

目的 探讨Ⅱ期直肠癌患者淋巴结微转移检测的临床意义。方法 对2000年1月至2001年8月行全直肠系膜切除术的42例Ⅱ期直肠癌标本的484枚淋巴结行间断病理切片结合细胞角蛋白20（CK20）免疫组化染色检测，根据随访资料结合文献分析Ⅱ期直肠癌患者系膜淋巴结微转移的临床意义。结果 42例患者中淋巴结微转移发生总例数为15例，发生率为35．7％（15／42），淋巴结微转移检出总数为33枚，检出率为6．8％（33／484）。随访12～80个月，以60个月为界，31例存活，11例死亡。淋巴结微转移阳性患者5年生存率为40．0％，淋巴结微转移阴性患者5年生存率为92．6％。经Log—rank检验两者的生存率比较差异有统计学意义（P=0．000）。Cox比例风险回归模型分析示淋巴结微转移的RR值为11．435，是惟一引入的危险因素。结论 淋巴结微转移是Ⅱ期直肠癌患者重要的预后指标，淋巴结微转移是直肠癌患者术后复发转移的独立预后指标，有淋巴结微转移的直肠癌术后患者可能从化疗中受益。

Objective To explore the clinical significance of lymph node micrometastases in stage Ⅱ rectal cancer patients. Methods Forty-two patients with rectal cancer uhderwent total mesorectal excision between January 2000 and August 2001 were included ,484 lymph nodes were studied in paraffin blocks that had previously been considered free by conventional histopathological examination. These lymph nodes were submitted to immunohistocbemical analysis using cytokeratin 20 （CK20） monoclonal antibodies to identify micrometastases. Five-year follow-up information was obtained on these patients. Observed survival rates and assessed respectively in the patients with and without micrometastases. Results Micrometastases were detected in 33 lymph nodes （6.8% ,33/484） of 15 cases （35.7%, 15/42）. The five-year survival rate was 40.0% in the patients with micrometastases, whereas in the patients without micrometastases, the survival rate was 92.6%（P= 0.000,by the Log-rank test）. By multivariate Cox regression analysis, lymph node micrometastases was closely correlated with post-operative recurrence or metastases, the value of RR was Ⅱ.435. Conclusions Detection of micrometastases is an important prognostic tool in stage Ⅱ rectal cancer. In this study,lymph nodes is an independent prognostic factor for overall survival. These patients maybe get benefit from adjuvant chemotherapy.