探讨DPYD、MTHFR基因多态性与直肠癌新辅助治疗的相关性

The Correlation Between the Polymorphism of Genes DPYD and MTHFR and the Neoadjuvant Chemotherapy of Rectal Cancer

目的探讨DPYD、MTHFR基因多态性与进展期直肠癌新辅助放化疗疗效的相关性,为临床进展期直肠癌患者新辅助放化疗提供依据.方法抽取26例低位进展期直肠癌患者外周血进行DPYD、MTHFR基因多态性分析,并对该组患者采取新辅助放化疗.结果全组全部完成新辅助治疗,所有患者均行手术治疗,手术后病理分期:T0N0M0期1例,T2N0M0期1例,T2N1M0期1例,T3N0M0期6例,T3N1M0期7例,T4N0M0期4例,T4N1M0期6例.18例(69.2%)患者肿瘤降期,其中10例患者存在MTHFR的667位点C/T杂合子突变,2例患者存在MTHFR的667位点T/T纯合子突变,8例未降期患者中,4例患者存在MTHFR的667位点C/T杂合子突变,无T/T纯合子突变.所有患者DPYD基因Exon13 c.1679位点均为T/T野生型.Exon14 IVS14+1位点均为G/G野生型.结论对于局部进展期低位直肠癌辅助放化疗可使部分肿瘤降期,DPYD基因联合MTHFR基因多态性的检测可做为直肠癌新辅助治疗个体化治疗的分子标记物.

Objective To investigate the correlation between the polymorphism of genes DPYD and MTHFR and the neoadjuvant chemotherapy of rectal cancer in developed stage, which will provide evidence for neoadjuvant chemotherapy of developed rectal cancer. Methods The polymorphism of genes DPYD and MTHFR in 26 patients of developed lower rectal cancer was analyzed with peripheral blood. The patients were treated with neoadjuvant chemotherapy. Results All the patients completed neoadjuvant chemotherapy and received surgical treatment. The post-surgical pathologic stages included 1 case of T0N0M0, 1 case of T2N0M0, 1 case of T2N1M0, 6 cases of T3N0M0, 7 cases of T3N1M0, 4 cases of T4N0M0 and 6 cases of T4N1M0. The pathologic stage in 18 patients (69.2%) was reduced. There was heterozygous C/T mutation in 10 patients and homozygous T/T mutation in 2 patients in the 667 site of MTHFR. In the 8 patients without stage reduction, there was heterozygous C/T mutation in 4 patients in the 667 site of MTHFR and there was no homozygous T/T mutation. The c.1679 site of gene DPYD Exon13 was wild-type T/T gene-type in all patients. The IVS14+1 site of gene Exon14 was all wild-type G/G gene-type. Conclusion Neoadjuvant chemotherapy for developed lower rectal cancer can reduce the pathologic stage in some patients. Combined measurement of the polymorphism of genes DPYD and MTHFR can be used as biomarker for individualized treatment of neoadjuvant chemotherapy for rectal cancer.