Clinical and Biological Predictors of Survival Following Relapse in Pediatric Medulloblastoma

Children with recurrent medulloblastoma face a dismal prognosis, prompting this study to investigate factors that may predict survival after relapse. We retrospectively examined clinical and biological data collected at initial diagnosis, along with key characteristics observed at relapse, for pediatric patients diagnosed with medulloblastoma between 2007 and 2017 at Gustave Roussy and Necker Hospital. Among 155 patients, 48 (31%) experienced a relapse over a median follow-up of 6.6 years (range, 0.4–12.3 years). The interval from diagnosis to relapse ranged from 1.2 to 87.2 months, with a median of 14.3 months. Relapse patterns included local recurrence in 9 patients, metastatic spread in 22, and combined local and metastatic disease in 17. Second-line interventions involved chemotherapy in 31 cases, radiotherapy in 9, SHH inhibitors in 4, while 4 patients received no further treatment. The overall survival rate at one year post-relapse was 44.8% (95% CI, 31.5–59.0%). Survival outcomes were closely linked to molecular subgroup at initial diagnosis, and additional factors such as radiotherapy during relapse and a longer interval before the first relapse (>12 months) may also influence post-relapse survival.