Diagnostic and prognostic value of IDH1 mutation in gliomas

Abstract

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 Ⅲ and 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 WHOⅡ, Ⅲ and Ⅳ gliomas 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 WHOⅣ 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, Ⅲ and Ⅳ gliomas, and the mutation rates of WHOⅡ 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． DOI：10.3969/j.issn.1672⁃6731.2012.06.015