Survival outcomes of giant cell glioblastoma: institutional experience in the management of 20 patients.

Giant cell glioblastoma (GCG) is a rare subtype of glioblastoma (GBM) that is believed to carry an improved prognosis. However, given the rarity of this tumor, best management practices for GCG have yet to be ascertained. Here, we present our experience in managing GCG tumors at the University of California, San Francisco. Patients were retrospectively identified through chart review, and data pertaining to patient demographics, treatment plans, and follow-up were extracted from existing medical records. Overall survival (OS) and progression-free survival (PFS) were the primary and secondary endpoints, respectively. In sum, we identified 22 patients who were managed or followed for GCG. Most patients (78%) initially underwent subtotal resection as primary treatment for their tumor, and most also received post-operative adjuvant therapy (90%), with radiation being the most frequently administered modality (85%). Within this institutional cohort, median OS and PFS were 15.4 months and 5.7 months, respectively. On multivariate survival analysis, age (p=0.84), sex (p=0.05), and adjuvant radiation plus temozolomide (p=0.12) were not associated with prolonged OS. However, adjuvant radiation plus temozolomide was associated with longer PFS (p=0.01), and patients receiving this therapy demonstrated a median PFS of 32.9 months versus 13.1 months. These findings confirm the comparatively improved prognosis of GCG over GBM. Moreover, they suggest that extent of resection may not significantly delay recurrence or extend survival, and that combination radiation with temozolomide may represent the optimum adjuvant paradigm to delay tumor progression.