While no significant correlation was found between IDH-wildtype GBM and IDH-mutant astrocytoma cohorts for EOA, tumor progression, complication rates, tumor volume, or demographic characteristics, a significant negative correlation was noted in three studies between postoperative KPS and tumor progression (β = −0.07, p < 0.0001). This evidence concerns the gene IDH1 and astrocytoma (excluding glioblastoma).