Outcomes for Anaplastic Glioma Treated With Radiation Therapy With or Without Concurrent Temozolomide

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).

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).

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.

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.