Superior Efficacy of Gross Total Resection in Anaplastic Astrocytoma Patients Relative to Glioblastoma Patients

Introduction Because of their relative rarity, anaplastic astrocytomas (AAs) often are grouped with glioblastomas in clinical treatment paradigms. There are reasons, however, to expect that the therapeutic response of AAs may differ from those of glioblastoma. Here, we examined the clinical benefit of gross total resection (GTR) in AA relative to glioblastoma patients. Methods Using the Surveillance, Epidemiology and End Results database, we identified 2755 patients with AA and patients with 21,962 glioblastoma between 1999 and 2010. Surgical resection was defined as GTR, subtotal resection (STR), biopsy only, or no resection. Kaplan-Meier curves and multivariate Cox regression were used to assess the association between GTR and survival. Results The hazard of dying from the AA was reduced in GTR patients by 40% relative to STR patients. This reduction is 59% greater than that observed in glioblastoma where GTR was associated only with a 24% reduction relative to STR (P < 0.0001). The median survival for patients with AA who underwent GTR and subtotal resection were 64 and 24 months, respectively. For glioblastoma patients, the corresponding numbers for median survival were 13 and 9 months, respectively. The survival benefit of GTR in patients with AA was particularly notable in patient age < 50, where the median survival was not reached during the study period. Conclusions The Surveillance, Epidemiology and End Results data suggest that survival benefit associated with GTR was greater for patients with AA relative to glioblastoma patients, particularly for patients < age 50.