Clinical Prognostic Value of the Isocitrate Dehydrogenase 1 Single-Nucleotide Polymorphism RS11554137 in Glioblastoma

Background The presence of the signal-nucleotide polymorphism (SNP) rs11554137:C>T in the IDH1 gene is associated with a significantly lower survival in acute myeloid leukemia patients. However, the impact of its presence in glioblastoma on patient survival is unclear.

Methods We conducted IDH1 gene sequencing on tumor samples from 176 adult patients with glioblastoma between 2013 and 2017. IDH1 gene status of the tumor sample was noted as either IDH1 wild type, mutant at codon 132, and having rs11554137:C>T SNP based on IDH1 gene sequencing. We conducted Kaplan–Meier and multivariate Cox survival analyses on overall and progression-free survivals based on IDH1 gene status. Patients' age at diagnosis, preoperative Karnofsky performance status score, treatment (extent of resection, postoperative radiotherapy, and temozolomide), and MGMT promoter methylation status of the tumor were also noted.

Results Presence of rs11554137:C>T SNP in glioblastomas samples did not correlate with presence of IDH1 mutation. Patients with rs11554137:C>T SNP did not have a history of a prior low-grade glioma. Patients with IDH1 mutant glioblastomas have a distinctly higher survival profile than both rs11554137:C>T SNP and IDH1 wild-type glioblastomas. No survival difference was noted between patients with glioblastoma harboring the SNP and IDH1 wild type.

Conclusion Clinical prognostication in glioblastoma patients is largely dependent on the classification of IDH1 mutant and wild-type glioblastoma, and not on the presence of rs11554137:C>T SNP in the tumor.