Clinical prognostic value of the isocitrate dehydrogenase 1 single-nucleotide polymorphism rs11554137 in glioblastoma

The presence of the single-nucleotide polymorphism (SNP) rs11554137:C>T in the IDH1 gene is associated with a significantly lower survival in acute myeloid leukemia patients. The impact of its presence in glioblastoma on patient survival is unclear. We retrospectively reviewed 171 adult (> 18 years of age) patients treated at a single, tertiary academic center for supratentorial glioblastoma (WHO grade IV) between 2013 and 2017. We conducted Kaplan–Meier overall and progression free survival analyses based on the IDH1 and IDH2 gene status of patients’ glioblastoma (IDH wild type, mutant, and IDH1 rs11554137:C>T SNP). Multivariate Cox survival analyses were conducted accounting for age at diagnosis, preoperative Karnofsky performance status score, treatment (extent of resection, postoperative radiotherapy, and temozolomide), IDH gene variant, and MGMT promoter methylation status. Presence of rs11554137:C>T SNP in glioblastoma samples did not correlate with presence of IDH1 mutation. Patients with rs11554137:C>T SNP did not have histories of prior lower-grade gliomas. Patients with IDH mutant glioblastoma had a distinctly higher survival profile than both rs11554137:C>T SNP and IDH wild type glioblastomas. No survival difference was noted between patients with glioblastoma harboring the SNP and patients with IDH wild type glioblastoma. In this study, clinical prognostication in glioblastoma patients was largely dependent on the classification of IDH mutant and wild type glioblastoma, and not on the presence of IDH1 rs11554137:C>T SNP in the tumor.