Lmic-24. Assessing the Treatment Outcomes of Pediatric Patients With Medulloblastoma Under a U.S.-MEXICO Cross-Border Neuro-Oncology Program

Abstract BACKGROUND Treating pediatric brain tumors in low-income countries is associated with worse outcomes, likely due to requiring a highly trained interdisciplinary team with ample resources. The Cross-Border Neuro-Oncology Program (CBNP) between Rady Children’s Hospital, San Diego (RCHSD), and Hospital General, Tijuana (HGT), was established to provide comprehensive care for children with brain tumors diagnosed at HGT. Given the most common malignant pediatric brain tumor is medulloblastoma, assessing treatment outcomes for this tumor is essential to establish this program’s validity. METHODS Pediatric patients with medulloblastoma were recruited from 2012-2021 as part of CBNP and risk-stratified into one of two treatment protocols (low - (K) versus high-risk (Y)). Patients underwent surgical resection and chemotherapy, which included cisplatin, etoposide, vincristine, and cyclophosphamide; patients with higher risk additionally received radiation therapy and higher-dose chemotherapy. Clinicopathologic profiles, extent of resection, methylation status and protocol type were analyzed and compared to known prognostic values for pediatric medulloblastoma. RESULTS Seventeen patients with medulloblastoma (age at diagnosis=6.8±5.0 years) were treated as part of CBNP during the study period. Patients were admitted to HGT, underwent resection at RCHSD, and returned to HGT for collaborative management. The mean symptom duration preceding diagnosis was 72.1±99.2 days. Gross total resection was achieved in 53% of cases and 5-year overall survival was 53% (9/17). Eight (47%) patients had residual post-treatment cerebellar signs. Survival data correlated with protocol type and methylation status will be presented. CONCLUSION Our cohort demonstrated a 5-year overall survival of 53%, moderately lower than the reported average 5-year overall survival of ~70% for pediatric medulloblastoma, with the majority of our cohort comprising of higher risk subtype and pathology. This indicates that this twinning model is a valid archetype for treating pediatric patients with brain tumors in low-income countries.