MPC-02 Prognostic effects of molecular factors in elderly patients with IDH-wildtype Glioblastomas

BACKGROUND: Geriatric neuro-oncology is an important research field, because the elderly patients is growing at a very rapid rate. This study investigates molecular features and their prognostic effects in the elderly glioblastomas (GBM). METHODS: We collected adult cases diagnosed with IDH-wildtype GBM and enrolled in Kansai Molecular Diagnosis Network for CNS Tumors (212 cases). Clinical and molecular features were analyzed retrospectively and independent prognostic factors were identified statistically. Focusing on the elderly (>=70 years) cases, the association between molecular factors and overall survivals (OS) was examined. RESULTS: Included in the study were 92 elderly cases (43.4%) and median OS was 12.8 months. MGMT promoter was methylated in 50 (54.3%). Triple CNA (EGFR amplification/gain & PTEN deletion & CDKN2A deletion) was detected in 23 (25.0%). NFKBIA was deleted in 23 (25.0%). In the elderly cases, adjuvant radiation and temozolomide (RT+TMZ) was performed in 39 (42.4%) (mOS = 17.1 months). Statistical analyses of the elderly plus non-elderly cases treated with RT+TMZ (148 cases), MGMT promoter, triple CNA and NFKBIA were identified as independent molecular prognostic factors. In the elderly group, however, there was no significant difference in OS according to MGMT status (methylated = 18.7 vs. unmethylated = 17.1, p = 0.3885) or triple CNA status (triple = 13.6 vs. non-triple = 19.6, p = 0.1734). On the other hand, statistical difference was observed according to NFKBIA status (del = 12.1 vs. non-del = 18.7, p = 0.0157*) even in the elderly cases. CONCLUSION: Prognostic effects of molecular factors might be attenuated in the elderly patients. Further investigation in a larger population is necessary.