Objectives: Postoperative management of anaplastic glioma remains without a clear standard of care-in this study we report outcomes for patients treated with radiotherapy (RT) with and without temozolomide (TMZ).
Materials and methods: We identified 71 consecutive patients with World Health Organization grade III glioma treated with either RT alone or with concurrent TMZ (RT+TMZ), between 2000 and 2013. Tumor histology was anaplastic astrocytoma in 42 patients, anaplastic oligodendroglioma in 25 patients, and anaplastic oligoastrocytoma in 4 patients. In total, 26 patients received RT and 45 received RT+TMZ. Adjuvant TMZ was administered to 12/26 (46.1%) patients who received RT and 42/45 (93.3%) patients who received RT+TMZ. Time-to-event endpoints included progression-free survival (PFS) and overall survival (OS).
Results: Kaplan-Meier estimates revealed that patients receiving RT+TMZ followed by adjuvant TMZ had improved PFS (P=0.04) and OS (P=0.02) as compared with those receiving RT followed by adjuvant TMZ. Cox proportional hazards multivariate analysis revealed improved PFS and OS with RT+TMZ for all patients (PFS: hazard ratio [HR]=0.42, P=0.02; OS: HR=0.41, P=0.03) and for anaplastic astrocytoma patients (PFS: HR=0.35, P=0.03; OS: HR=0.26, P=0.01), regardless of whether patients received further adjuvant TMZ.
Conclusions: These findings support the use of RT+TMZ in the postoperative management of grade III glioma, and suggest that there is a benefit to concurrent RT+TMZ that is independent of adjuvant monthly TMZ. Further investigation is warranted, both to prospectively validate the benefit of RT+TMZ, as well as to determine if an additional benefit truly exists for adjuvant TMZ following concurrent RT+TMZ.