Table 5. Cox regression model in association with prognoses in the WHO₂₀₀₇ cohort (N=421).

Factors	PFS		OS
	OR (95% CI)	P value	OR (95% CI)	P value
1q/19p co-polysomy (yes/no)	0.538 (0.374-0.772)	0.001	0.460 (0.287-0.738)	0.001
Age (≤40/>40)	0.715 (0.536-0.955)	0.023	0.627 (0.428-0.918)	0.017
Tumor grade (IV/III/II)	2.124 (1.808-2.495)	<0.001	2.250 (1.843-2.747)	<0.001
Removal degree (GTR/non-GTR)	0.592 (0.455-0.772)	<0.001	0.461 (0.337-0.630)	<0.001

PFS=progression-free survival; OS=overall survival; OR=odd ratio; CI=confidence interval. GTR=gross-total resection.