直肠癌环周切缘组织中CD133的表达及临床意义

Expression and clinical significance of CD133 in circumferential resection margin of rectal cancer

目的检测直肠癌环周切缘组织内是否含有肿瘤干细胞,并观察环周切缘浸润对患者预后的影响。方法取直肠癌患者手术切除标本的环周切缘,4%甲醛固定后做成病理切片;根据环周切缘有无浸润分为环周切缘阳性组和环周切缘阴性组,2组均做免疫组织化学标记CD133肿瘤干细胞,观察CD133表达情况;随访2组患者术后1～2年复发情况。结果环周切缘阳性组免疫组织化学标记CD133+,存在CD133+肿瘤干细胞,但与环周切缘阴性组相比无统计学意义(P>0.05)。环周切缘阳性组患者1～2年复发率显著高于阴性组(P<0.05)。结论环周切缘浸润是导致直肠癌患者术后复发的重要因素,部分环周切缘浸润中存在肿瘤干细胞。

Objective To verify the presence of cancer stem cells within circumferential resection margin,and to determine the relation between cancer stem cells and prognosis of rectal cancer.Methods The circumferential resection margin of rectal cancer was harvested and postfixed by using 4% formaldehyde for preparation of pathological sections.The sections were divided into circumferential resection margin positive group and negative group according to the presence of malignant cells.Immunohistochemistry assay was employed to label the CD133＋ cancer stem cells,thus allowing for assessment of CD133 expression.Patients were followed by for 1-2 years to determine the rate of relapse of rectal cancers.Results CD133＋ cancer stem cells were detected in the circumferential resection margin positive group by immunohistochemistry assay; however,the difference in the magnitude of expression was unmarked compared with circumferential resection margin negative group （P〉0.05）.The 1-2 years relapse rate was higher in circumferential resection margin positive group than in circumferential resection margin negative group （P〈0.05）.Conclusion The circumferential margin involvement is key factor leading to relapse and metastasis of rectal cancers.Cancer stem cells exist in a subgroup of the circumferential resection margin.