Popis: |
BACKGROUND IDH-mutant glioblastoma is classified by the 2016 CNS WHO as a group with good prognosis. However, the actual number of cases examined in the literature is relatively small. We hypothesize that IDH-mutant glioblastoma is not a uniform group and should be further stratified. MATERIAL AND METHODS We conducted methylation profiles and estimated copy number variations in 64 IDH-mutant glioblastomas. RESULTS Our results showed that 10.9%, 53.1%, and 35.9% of tumors belonged to Codel, G-CIMPhigh, and G-CIMP-low methylation subgroups, respectively. G-CIMP-low subgroup was associated with significantly worse OS as compared to G-CIMP-high (P=0.005) and Codel groups (P=0.009). CDKN2A deletion (37.5%) was the most common gene copy number variation, and was associated with G-CIMP-low subgroup (P=0.001). Other frequent copy number changes included MET (4.7%), CCND2 (17.2%), PDGFRA (14.1%), CDK4 (12.5%), and EGFR (12.5%) amplification. Both CDKN2A deletion (P=0.008) and MET amplification (P CONCLUSION IDH-mutant glioblastomas should be stratified for risk with combined epigenetic signature and CDKN2A/MET status and some cases have poor outcome. |