Table 4. Multivariate analysis comparing established prognostic biomarkers from the literature to variables identified as significant in the multivariate analysis, utilising a forward selection strategy for OS.

Variable			HR	95% CI	P value*
EOR			0.347	0.129–0.936	0.037
Previous surgery			2.091	0.689–6.344	0.193
Age at diagnosis			1.008	0.969–1.049	0.692
IDH mutation			0.000	0.000–0.000	0.975
MGMT methylation			0.507	0.187–1.377	0.183
ECOG
	Preoperative
		1 vs 0	0.827	0.265–2.580	0.743
	Postoperative
		1 vs 0	1.055	0.394–2.825	0.916
		2 vs 0	0.587	0.172–2.004	0.395
		3 vs 0	0.000	0.000–0.000	0.990

EOR = extent of resection, IDH = isocitrate dehydrogenase, MGMT = O⁶methylguanine DNA methyltransferase, ECOG = Eastern Cooperative Oncology Group.

*P values in bold are significant.