二代测序技术检测转移性结直肠癌患者循环肿瘤DNA中RAS/BRAF突变状态的研究

Detection of RAS/BRAF Mutations in the ctDNA of mCRC Patients by NGS Technique

目的探讨采用二代测序技术(NGS)检测转移性结直肠癌患者循环肿瘤DNA中RAS/BRAF突变状态代替组织检测的可行性,并分析影响血液与组织基因检测结果一致性的因素。方法选取2015年11月份至2016年7月份我院收治的108例转移性结直肠癌患者,运用NGS检测循环肿瘤DNA中RAS、RAF的突变状态,与标准组织检测方法结果进行比较。结果血液、组织KRAS检测结果一致的为62例,不一致33例,整体一致性65.26%。BRAF突变检测结果一致共89例,不一致6例,整体一致性93.68%,NRAS基因检测结果 92例一致,不一致3例,一致性为96.84%。结论采用二代测序技术检测转移性结直肠癌患者循环肿瘤DNA中RAS/BRAF突变状态代替组织检测具有有效性和可行性,化疗、靶向治疗、肿瘤异质性等因素是影响血液与组织检测结果是否一致的主要因素。

Objective To investigate the feasibility of circulating tumor DNA instead of tissue DNA in metastatic colorectal cancer by NGS technique and analyze the consistency of blood and tissue genetic test results. Methods 108 patients with mCRC were collected between November, 2015 and July, 2016. The mutation status of RAS and RAF was detected by NGS technique, and these results were compared with those of standard tissue detection. Results The results of KRAS were consistent in 62 cases, inconsistent in 33 cases and the consistent rate was 65.26%. There were 89 BRAF mutation cases, 6 results of patients were inconsistent, and the consistent rate was 93.68%. 92 cases of NRAS gene were consistent, 3 cases were inconsistent, and the consistency rate was 96.84%. Conclusion It is effective and feasible to detect ctDNA instead of tissue by NGS technique in mCRC. Chemotherapy, targeted therapy, tumor heterogeneity and other factors are the main factors influencing the consistency of blood and tissue DNA test results.