结直肠癌中DNA错配修复功能缺陷与血管密度的相关性

Correlation between DNA mismatch repair defects and vascular density in colorectal cancer

目的:探讨DNA错配修复功能缺陷(deficient mismatch repair,dMMR)在结直肠癌中的临床病理特征及与血管密度的关系。方法:选取2016年1月至2018年12月因结直肠癌于广州市红十字会医院住院行根治手术的患者样本。采用免疫组织化学法检测101例患者样本中MMR蛋白(MLH1、MSH2、MSH6、PMS2)用以判断dMMR;检测CD34和D2-40以计算血管密度。结果:101例结直肠癌患者癌组织中,d MMR共有18例(17.8%),肿瘤位于右半结肠、肿瘤最大径<5cm及肿瘤低分化比例较高,淋巴结转移率较低(均P<0.05)。d MMR与肿瘤浸润深度及是否远处转移无关。dMMR者具有较低的血管密度及淋巴管密度,MMR蛋白表达与血管密度及淋巴管密度呈正相关(均P<0.05)。结论:dMMR与结直肠癌肿瘤大小、位置及分化程度密切相关,dMMR患者的低淋巴结转移率与较低的血管及淋巴管密度相关。

Objective:To investigate the correlation of clinicopathologic features of deficient mismatch repair(d MMR)defects in colorectal cancer and vessel density.Methods:Samples of colorectal cancer patients admitted to Guangzhou Red Cross Hospital from January 2016 to December 2018 were selected.Immunohistochemistry was applied in 101 samples to detect four MMR proteins(including MLH1,MSH2,MSH6,and PMS2)so as to estimate d MMR.CD34 and D2-40 were used to detect microvessel density and microlympatic density.Results:In 101 cases of cancer tissue,18(17.8%)samples were detected as d MMR defects,which was characterized by tumor located in the right colon,with the maximum diameter less than 5 cm,higher proportion of poor differentiation and lower rate of lymphatic metastasis(all P<0.05).d MMR had no relationship with depth of tumor invasion and distant metastasis.The d MMR patients had lower microvessel and microlympatic density.There was positive correlation between MMR protein expression and microvessel and microlympatic density(all P<0.05).Conclusion:d MMR is closely associated with tumor location,tumor size and tumor differentiation.The reduced rate of lymphatic metastasis in d MMR is correlated with lower density of microvessel and microlympatic density.