不接触分离技术抑制结直肠癌术中癌细胞门静脉播散的临床研究

目的：从基因水平评估“不接触分离技术”是否对结直肠癌术中癌细胞门静脉播散起抑制作用。方法：应用突变等位基因特异性扩增法（MASA），检测结直肠癌术中处理 肿瘤前、中、后期的门静脉血中癌细胞播散情况。46例结直肠癌患中，22例施行传统手术，24例应用“不接触分离技术”。在打开腹腔处理肿瘤前，经胃网膜右静脉在门静脉中置入一静脉导管，然后分别于处理肿瘤前、中、后期经导管各采血10ml。用MASA法检测肿瘤特异性标记物－K－ras的12、13、61密码子和P53的5、6、7、8 外显子，并用3′末端20bp的寡核苷酸作为PCR的引物。结果：22例接受传统手术的患中，15例体细胞有突变，其中12例（80．0％）术中在门静脉血中用MASA法检测到原发肿瘤细胞特异性标记物；而在24例“ 不接触分离技术”中，有17例发现有K-ras和P53基因的突变，其中仅2例（11．8％）在术中于门静脉血中检测到原发肿瘤细胞特异性标记物；显示传统手术操作与癌细胞播散呈正相关（P＜0．05）。经随访，传统手术组术后2年内，有5例出现肝转移，并有4例死亡；而“不接触分离技术”组，术后2年内仅1年出现肝转移并死亡。结论：与传统手术相比，“不接触分离技术”能抑制结直肠癌手术操作过程中癌细胞的门静脉播散，有效地降低结直肠癌的肝转移率，提高患的2年生存率。

No touch isolation technique reduces intraoperative shedding of tumor cells into the portal vein during resection of colorectal cancer

Objective To evaluate whether the no touch isolation technique contributes to the prevention of cancer cells from spreading into portal veins during resection of colorectal cancer at genetic level.Methods Forty six cases with colorectal cancers,22 with conventional operation and 24 with no touch isolation technique, were screened mutant allele specific amplification (MASA) for mutations in K ras or P53.Blood samples of the portal vein collected before, during and after manipulation of tumors were examined using MASA to look for the specific mutation found in the primary tumors. Results Somatic mutations were identified in 32 of these primary tumors, of whom 15 in the conventional resection technique group and 17 in the no touch isolation technique group.In 12 of 15 cases (80.0%) of conventional resection technique cases, the same genetic alteration of the primary tumor identified was in the portal blood during operation, whereas only 2 patients (11.8%) of the no touch isolation technique group had a positive result. Conclusion No touch isolation technique may be useful to prevent cancer cells from shedding into the portal vein during surgical manipulation.