Longitudinal epigenome analysis of IDH-mutant astrocytomas from initial and recurrent surgical specimens

Genome-wide DNA methylation profiling of 31 IDH-mutant astrocytoma tumor specimens, of which 14 are from initial surgical resections prior to any radiation or chemotherapy and 17 of which are from a second surgical resection at time of recurrence/progression usually following radiation and/or chemotherapy. For 7 patients (#201-#207), there are paired initial and recurrent tumor samples that were analyzed. For the remaining 17 patients, there are 7 (#208-#214) with only an initial tumor sample analyzed and 10 (#215-#224) with only a recurrent tumor sample analyzed. The Illumina Infinium EPIC 850k Human DNA Methylation Beadchip was used to obtain DNA methylation profiles across approximately 850,000 CpG sites of genomic DNA extracted from formalin-fixed, paraffin-embedded tumor tissue of the 31 IDH-mutant astrocytomas. Bisulfite converted genomic DNA extracted from the 31 IDH-mutant astrocytoma tumor samples was hybridized to Illumina Infinium EPIC 850k Human DNA Methylation Beadchips