Table 4.

Results of multivariate analysis in the favorable subgroups (gross total resection or WHO grade II)

	HR	95% CI	p-valuea)
Patients undergoing gross total resection
Overall survival
Age (≥ 60 yr vs. < 60 yr)	2.880	0.537–15.446	0.217
Disease-free survival
PORT (PORT vs. surgery only)	0.248	0.111–0.554	< 0.001
Ki-67 (≥ 10 % vs. < 10 %)	2.534	1.122–5.725	0.025
Local control rate
ECOG (0 vs. 1–3)	1.084	0.485–2.424	0.845
PORT (PORT vs. surgery only)	0.245	0.093–0.500	< 0.001
Distant metastasis-free survival
Tumor location (infra- vs. supratentorial)	0.623	0.217–1.794	0.154
WHO grade (II vs. III)	1.371	0.566–3.318	0.484
Patients with WHO grade II
Overall survival
Age (≥ 60 yr vs. < 60 yr)	6.173	1.268–30.052	0.024
Surgical extent (STR vs. GTR)	0.663	0.129–3.421	0.624
Disease-free survival
Surgical extent (STR vs. GTR)	2.156	0.833–5.576	0.113
PORT (PORT vs. surgery only)	0.128	0.039–0.420	0.001
Ki-67 (≥ 10 % vs. < 10 %)	4.173	0.868–20.068	0.075
Local control rate
ECOG (0 vs. 1–3)	0.376	0.048–2.936	0.351
Surgical extent (STR vs. GTR)	4.057	1.818–9.056	0.001
PORT (PORT vs. surgery only)	0.215	0.093–0.500	< 0.001
Distant metastasis-free survival
Tumor location (infra- vs. supratentorial)	0.242	0.067–0.874	0.030

CI, confidenceinterval; ECOG, Eastern Cooperative Oncology Group; GTR, gross total resection; HR, hazard ratio; PORT, postoperative radiotherapy; STR, subtotal resection; WHO, World Health Organization.

^a)Cox proportional hazard model. Multivariate analysis in the subgroup included only the significant factors in the whole group.