大切片CK20染色对中下段直肠癌远端转移的研究

目的 探讨中下段直肠癌远端壁内浸润和系膜转移的频率、类型,确定合适的病灶远端切除长度.方法 收集中山大学肿瘤医院2004年8月至2005年12月中下段直肠癌标本34例,山东省立医院2006年10月至2007年10月中下段直肠癌标本28例,分别用HE和CK20(cytokeratin,CK)染色,观察中下段直肠癌远端癌灶存在形式及分布规律.Logistic回归分析筛选与中下段直肠癌发生远端壁内浸润和系膜转移的临床病理因素.结果 直肠癌远端肠壁浸润形式为:黏膜下或肌肉间浸润发生率为16%(10/62),扩散距离0.5～1.0 cm.直肠癌远端系膜转移形式为:淋巴结转移、脉管转移、周围神经转移、孤立癌灶,发生率为24%(15/62),扩散距离0.5～4.0 cm.CK20染色观察3例患者存在远端系膜癌灶.Logistic单因素分析显示,血CEA水平、淋巴结转移、环周切缘癌浸润(circumferential margin involvement,CMI)和TNM分期与中下段直肠癌远端肠壁浸润和系膜转移有关.多因素分析显示,TNM分期是中下段直肠癌远端转移的独立影响因素(Wald=9.567,P=0.002).结论 TNM分期是影响中下段直肠癌远端壁内浸润和系膜转移的独立因素.直肠癌手术切除远端肠管长度达1.5 cm即可,但必须保证切除远端系膜长度不少于5 cm.

Distal spread of low and middle rectal cancer in mesorectum and rectal wall found by large slices stained with CK20

Objective To examine the frequency and mode of distal spread of low and middle rectal cancer in the mesorectum and rectal wall. Methods Thirty-four specimens from low and middle rectal cancer were collected between August 2004 and December 2005 in Cancer Center of Sun Yat-sen University. Twenty-eight specimens of low and middle rectal cancer were collected between October 2006 and October 2007 in Shandong Provincial Hospital of Shandong University. All 62 specimens were studied using large slices stained with CK20. Logistic regression was used to analyze clinicopathologic factors related to distal spread of low and middle rectal cancer in the mesorectum and rectal wall. Results Two types of distal spread of the tumor were observed in rectal wall: submucosa invasion and muscularis propria invasion. Distal spread in rectal wall was observed in 16% (10/62) of the patients. The length of distal spread in rectal wall was found from O. 5 cm to 1.0 cm. Four types of distal spread of the tumor were observed in mesorectum: lymph node invasion, blood and lymphatic vessel invasion, perineural invasion, isolated neoplastic microfoci. Distal spread in mesorectum was observed in 24% (15/62) of the patients. The length of distal spread in mesorectum was found from 0. 5 cm to 4. 0 cm. Three more cases with microcapillary invasion in distal mesorectum was observed by immunohistochemical technique, which was difficult to identify by conventional HE staining. Univariate analysis showed that serum CEA , lymph node invasion, CMI and TNM stage were correlated with distal spread of low and middle rectal cancer in the mesorectum and rectal wall. TNM stage was shown to be independent impact factor by multivariate analysis( Wald = 9. 567, P =0. 002). Conclusion TNM stage is an independent impact factor for distal spread of low and middle rectal cancer in the mesorectum and rectal wall. Resection of 1.5 cm for distal rectal wall is necessary for a curative intention, but it must be emphasized that the clearance for distal mesorectum should be 5 cm at least.