NCOG-12. TREATMENT AND MORTALITY OF PRIMARY BRAIN TUMORS: A SINGLE CENTER OBSERVATIONAL STUDY OF GLIOBLASTOMAS AND ASTROCYTOMAS

Abstract Glioblastoma multiforme (GBM) is a WHO grade IV malignant tumor with a relatively poor prognosis (median survival of 15 months). Astrocytomas are WHO grade I-III tumors with a better prognosis than GBM; their median survival ranging from 2-10 years. We assessed the response to various mainstay treatment modalities in patients with GBM and astrocytoma, expecting to find that surgery and stereotactic radiation (SRS) treatment confer greater survival benefits than non-surgical and whole brain radiation (WBRT) options. We analyzed 108 patients at St. Luke’s University Health Network (SLUHN) who were previously diagnosed with a primary brain tumor consistent with GBM (90) or astrocytoma (18) prior to January 1, 2023. Mainstays of treatment were surgery with or without different radiation modalities (WBRT and SRS, and WBRT+SRS). Glioblastoma typically affected older patients (65.5), had mostly single lobe involvement (86.7%), and was predominantly located in the frontal (41.1%) and temporal lobes (37.7%). Astrocytoma was slightly younger (51.2), less often single lobe (72.2%), and mostly involved the frontal (44.4%), temporal (44.4%), and parietal lobes (33.3%). GBM found the greatest benefit from WBRT (without co-occurring SRS) with an increase of 16.4 months to 20.2 months (p=.789). Surgery, regardless of radiation status, appeared to provide the greatest benefit for patients with astrocytoma increasing average lifespan from 36.7 months to 53.6 months (p=.181). Patients with glioblastoma that underwent surgery also had increased survival of 18.2 months compared with nonsurgical patients at 12 months (p=0.097). While we were interested to see the impact these treatment modalities had on patient survival, our sample size was small and our results lacked statistical significance. Future studies with greater sample sizes would help determine whether statistical significance is correlated with meaningful clinical outcomes.