IDH1基因突变对胶质瘤诊断及预后意义

Diagnostic and prognostic value of IDH1 mutation in gliomas

目的通过对幕上胶质瘤细胞IDH1基因突变检测,研究IDH1基因突变对胶质瘤临床诊断及预后的意义。方法提取315例幕上胶质瘤(WHOⅠ级3例、Ⅱ级95例、Ⅲ级37例、Ⅳ级180例)患者手术切除标本IDH1基因DNA,经聚合酶链反应扩增后直接测序,同时对患者年龄、性别、肿瘤生长部位、切除范围、Karnofsky生活质量评分和生存时间等进行多因素分析,了解IDH1基因突变对患者预后的影响。结果经对315例胶质瘤标本测序共发现112例发生IDH1基因突变,突变率约为35.56%,均为R132H型突变。不同病理分级胶质瘤基因突变率分别为WHOⅡ级72.63%(69/95)、Ⅲ级24.32%(9/37)、Ⅳ级18.89%(34/180),不同级别突变率比较差异具有统计学意义(均P=0.000);WHOⅣ级胶质瘤发生突变的患者中18例为原发性、16例为继发性胶质母细胞瘤,突变率分别为11.39%(18/158)和72.73%(16/22),后者显著高于前者且差异有统计学意义(χ2=23.654,P=0.001)。生存分析显示,IDH1基因突变对患者预后有显著影响。结论 WHOⅡ～Ⅳ级胶质瘤均可发生IDH1基因突变,其中以WHOⅡ级和Ⅳ级中的继发性胶质母细胞瘤基因突变率较高。IDH1基因突变对患者生存时间有明显影响,发生IDH1突变者预后良好,提示IDH1基因突变对胶质瘤患者诊断及预后有重要临床预测价值。

Objective To discuss the significance of IDH1 mutation for diagnosis and prognosis of gliomas through detecting of IDH1 mutation in supratentorial glioma cells. Methods IDH1 genes of postoperative pathological samples obtained from 315 patients with supratentorial gliomas （3 cases of WHO Ⅰ, 95 cases of WHO Ⅱ, 37 cases of WHO Ⅲand 180 cases of WHO Ⅳ） were collected for DNA extraction, on which PCR amplification and direct sequencing were done. At the same time, multiple-factor analysis was used on those patients age, sex, tumor location, excision extension, Karnofsky Performance Status （KPS） and progression-free survival time or median survival time, to investigate the influence of IDH1 mutation on the prognosis of patients. Results A total of 112 gene mutations among 315 cases （35.56%） were found and they were all R132H type of mutations. Mutation rates in WHO Ⅱ, Ⅲand Ⅳgliomas were 72.63%（69/95）, 24.32%（9/37） and 18.89%（34/180） respectively, which were significantly different （P = 0.000, for all）. Among patients with IDH1 mutations in WHO IV gliomas, there were 18 cases of primary glioblastoma and 16 cases of secondary glioblastoma, the mutation rates of which were 11.39% （18/158） and 72.73% （16/22）, respectively. The latter was much higher than the former and the difference was statistically significant （χ 2= 23.654, P= 0.001）. Survival analysis revealed that IDH1 mutation presented notable effect on the prognosis of patients with gliomas. Conclusion IDH1 mutation can happen in WHO Ⅱ, Ⅲand Ⅳgliomas, and the mutation rates of WHO Ⅱ gliomas and secondary glioblastomas of WHO IV are higher than others. The survival time of patients are remarkably influenced by IDH1 mutation, and the prognosis of patient with IDH1 mutation is good, which may suggest that IDH1 mutation is an important diagnostic and prognostic biomarker in different grades of gliomas.