10110- COT-11 EVALUATING SHORT-TERM SURVIVORS OF GLIOBLASTOMA: A PROPOSAL BASED ON SEER REGISTRY DATA

Abstract BACKGROUND Glioblastomas (GBMs) are central nervous system tumors with a poor prognosis and limited treatment options. Although small subsets of GBM patients survive longer than 3 years, there is little evidence regarding the prognostic factors of GBM. Therefore, we conducted a thorough characterization of GBM in the United States. METHODS We queried the Surveillance, Epidemiology and End Results database (SEER) between 2000 and 2021 to extract age-adjusted incidence rates (AAIR), age-adjusted mortality rates (AAMR), and survival data for GBM. Age group comparisons for each measure varied depending on the available SEER data. We compared trends in AAIR, AAMR, and survival time across age groups 0-14, 15-39, 40-69, and 70+ years. Also, we employed the Fine-Gray competing risk model among short-term survivors (STSs), defined as those with a survival time of 6 months or less, and long-term survivors (LTSs), defined as those with a survival time of 3 years or more. RESULTS This study included 16,625 STSs and 4,197 LTSs between 2000 and 2021. The mortality-to-incidence ratio was constant among STSs, whereas it increased with age among LTSs. Higher age and male sex were significantly associated with GBM-specific death among LTSs, whereas non-Hispanic White, subtotal resection/biopsy, no radiation therapy, and no chemotherapy were associated with GBM-specific death among STSs. Interestingly, higher age was significantly associated with other causes of death among STSs. CONCLUSIONS STSs partially consist of populations who died from causes other than GBM. It is important to include only GBM-specific deaths in STS groups to conduct reproducible research comparing STSs and LTSs.