Lmic-01. Survival and Prognostic Factors in Childhood Medulloblastoma Single Tertiary Center Experience From King Fahad Medical City KFMC Saudi Arabia

Abstract BACKGROUND Medulloblastoma (MB) is the most common childhood malignant brain tumor treated with intensive multimodalities therapy including Surgery, Craniospinal Radiation, and chemotherapy. Our study aims to document the clinical courses, prognostic factors, and survival outcomes in Saudi children above three years with Medulloblastoma treated in King Fahad Medical City KFMC. METHODS Retrospective analysis of MB patients diagnosed between January 2009 to January 2022 All patients received Risk-adapted Radiation therapy followed by maintenance chemotherapy,3 patients progressed and died after surgery and were excluded from analysis. RESULTS We identified 145 MB patients 65.5 % were male. median age at Diagnosis 7.00 years (range3-14 years), Age less than 5 years did not have a worse outcome in our cohort. Classic histology was predominant (80%), 42.1% of patients had metastatic disease at presentation; the Median time to start radiation therapy after surgery was 35 days. 51.7% were treated as High-Risk HR MB and Average Risk AR MB 48.3%. 65 cases having molecular testing for MB molecular subgroups. 6 patients 4.1% developed a second malignancy with a median time of 6 years post diagnosis. Multivariate survival analysis showed that progression-free survival was significantly reduced by the extent of surgical resection (P=0.021) and Metastatic MB at diagnosis(P=0.014). At Median follow-up of 7 years, Progression-free survival PFS and overall survival OS for the whole cohort were 72.4% and 71.7% respectively. PFS for AR MB and HR MB was 81.4% and 64.0% respectively. PFS analysis based on molecular subgroup: WNT subgroup 92.3%, SHH 69.2%, Group 4:57.7%:and group 3: 46.2%. CONCLUSIONS Our study is the largest analysis of childhood MB treatment outcomes in Saudi Arabia Defining the poor prognostic factor for these patients and will form the baseline for future pediatric Neuro-Oncology studies in KFMC, which may help to improve the outcome of childhood MB in Saudi Arabia.