Combining two biomarkers, IDH1/2 mutations and 1p/19q codeletion, to stratify anaplastic oligodendroglioma in three groups: a single-center experience.
Mutations in the isocitrate dehydrogenase (IDH) genes occur frequently in low-grade astrocytomas and oligodendrogliomas (World Health Organization [WHO] grade II), and in higher-grade gliomas (WHO grades III and IV) that arise after malignant progression of low-grade tumors.
Next-generation molecular biology technologies have recently identified recurrent CIC and FUBP1 point mutations in 1p/19q codeleted and IDH-mutated oligodendrogliomas.
IDH1 and IDH2 mutations are prognostic but not predictive for outcome in anaplastic oligodendroglial tumors: a report of the European Organization for Research and Treatment of Cancer Brain Tumor Group.
We found 165 IDH1 (72.7%) and 2 IDH2 mutations (0.9%) in 227 diffuse astrocytomas WHO grade II, 146 IDH1 (64.0%) and 2 IDH2 mutations (0.9%) in 228 anaplastic astrocytomas WHO grade III, 105 IDH1 (82.0%) and 6 IDH2 mutations (4.7%) in 128 oligodendrogliomas WHO grade II, 121 IDH1 (69.5%) and 9 IDH2 mutations (5.2%) in 174 anaplastic oligodendrogliomas WHO grade III, 62 IDH1 (81.6%) and 1 IDH2 mutations (1.3%) in 76 oligoastrocytomas WHO grade II and 117 IDH1 (66.1%) and 11 IDH2 mutations (6.2%) in 177 anaplastic oligoastrocytomas WHO grade III.
Mutations of the isocitrate dehydrogenase (IDH) metabolic enzymes IDH1 and IDH2 have been found to be frequent and early genetic alterations in astrocytomas and oligodendrogliomas.
We found 165 IDH1 (72.7%) and 2 IDH2 mutations (0.9%) in 227 diffuse astrocytomas WHO grade II, 146 IDH1 (64.0%) and 2 IDH2 mutations (0.9%) in 228 anaplastic astrocytomas WHO grade III, 105 IDH1 (82.0%) and 6 IDH2 mutations (4.7%) in 128 oligodendrogliomas WHO grade II, 121 IDH1 (69.5%) and 9 IDH2 mutations (5.2%) in 174 anaplastic oligodendrogliomas WHO grade III, 62 IDH1 (81.6%) and 1 IDH2 mutations (1.3%) in 76 oligoastrocytomas WHO grade II and 117 IDH1 (66.1%) and 11 IDH2 mutations (6.2%) in 177 anaplastic oligoastrocytomas WHO grade III.
Patient KK was a 68-yr-old female who was found to have a large, left-sided insular mass that was shown to be an oligodendroglioma WHO grade II, positive for codeletion 1p/19q and IDH1 mutant on biopsy.
Patients with IDH wild type anaplastic astrocytoma and glioblastoma had a significantly shorter median PFS (19.3 months vs. NR, p = 0.001) and median OS (43.5 months vs NR, p = 0.007) than those with IDH mutated grade III anaplastic astrocytoma and oligodendroglioma.
A total of 135 cases consisted of 38 IDH-mutant [17 astrocytoma (AC), 13 oligodendroglioma (OD) and eight glioblastoma (GBM)], 87 IDH-wildtype (six AC, three OD and 78 GBM), and 10 diffuse midline glioma, H3K27M-mutant.
The reported two cases were initially diagnosed as oligodendroglioma with 1p/19q-codeletion and mutation of <i>isocitrate dehydrogenase 1 (IDH1)</i>-R132H.
Gliomas were assigned to one of the three molecular groups: Group O (IDH-mutant, 1p/19q co-deleted oligodendrogliomas, n = 95), Group A (IDH-mutant, ATRX inactivated astrocytomas, n = 175) and Group G (IDH wild-type, GBM-like, n = 46).
The DSC-MRI procedure may provide insight into the IDH1/2 mutation and ATRX expression status and MGMT methylation profile of diffuse glioma; however, taking integrated oligodendroglioma into account limits the diagnostic performance of rCBV in non-invasively predicting the molecular subtype.
We excluded glioblastoma-like tumors (7a10d subgroup) and derived a gene expression signature distinguishing histologically classified oligodendrogliomas with concurrent 1p/19q co-deletion and IDH mutation (1p/19q subgroup) from those with predominant IDH mutation alone (IDHme subgroup).