Fig.

Kaplan–Meier analysis of relapse or survival

Fig. A: Progression free survival (PFS). Solid and dotted lines indicates the group aged 65–69 and ≥70, respectively. The median PFS with high-grade astrocytoma was 9.9 months and 6.9 months in patients aged 65–69 and ≥70, respectively (P = 0.10). Abbreviations; 95% CI, 95% confidence interval.

Fig. B: Overall survival (OS). Solid and dotted lines indicates the group aged 65–69 and ≥70, respectively. The median OS was 22.8 months and 11.6 months in patients aged 65–69 and ≥70, respectively (P = 0.009). Abbreviations; 95% CI, 95% confidence interval.

Fig. C: OS based on the number of independent predictive factors. Patients ≥70 were subdivided into four groups based on the number of the three independent prognostic factors (postoperative Karnofsky performance status, chemoradiotherapy as adjuvant therapy, and salvage therapy). Group 0: no prognostic factors, Group 1: one prognostic factor, Group 2: two prognostic factors, Group 3: three prognostic factors. Median OS of groups 0, 1, 2, and 3 was 7.2, 9.1, 18.4, and 27.0 months, respectively (P<0.001). Abbreviations; 95% CI, 95% confidence interval.