In a study reported in the Journal of Clinical Oncology, Erker et al identified factors associated with better postrelapse survival among infants and young children with medulloblastoma relapsing after initial craniospinal irradiation (CSI)-sparing curative-intent treatment. These factors included salvage CSI.
The study involved 294 patients treated with curative intent without initial CSI derived from an international, multi-institutional cohort of patients diagnosed at age < 6 years between 1989 and 2019. All patients experienced relapse after initial cytotoxic chemotherapy.
The 3-year postrelapse survival rate among the 294 patients was 52.4% (95% confidence interval [CI] = 46.4%–58.3%), with a median time to relapse from diagnosis of 11 months.
Salvage therapy included CRI in 73% of patients and chemotherapy in 77%.
Among 150 patients with available molecular subgrouping data, 3-year postrelapse survival was 60% for sonic hedgehog (SHH), 84% for group 4, and 18% for group 3 (overall P = .0187).
On multivariable analysis, factors associated with improved postrelapse survival were localized relapse (P = .0073), SHH molecular subgroup (P = .0103), CSI use after relapse (P= .0161), and age ≥ 36 months at initial diagnosis (P = .0494).
Salvage chemotherapy was not significantly associated with improved postrelapse survival on multivariate analysis. However, among patients receiving salvage CSI at < 35 Gy, the addition of systemic chemotherapy was associated with improved 3-year postrelapse survival vs CSI alone (55% vs 38%, P = .007). No benefit was observed with the addition of chemotherapy in patients receiving CSI at ≥ 35 Gy (P = .298).
In an exploratory propensity score–weighted analysis by molecular subgroup, group 3 patients had improved postrelapse survival with CSI vs no CSI (P = .0028), whereas no differences in survival were found for CSI vs no CSI among SHH and group 4 patients.
The investigators concluded, “A substantial proportion of patients with relapsed infant and young childhood medulloblastoma are salvaged after initial CSI-sparing approaches. Patients with SHH subgroup, localized relapse, older age at initial diagnosis, and those receiving salvage CSI show improved postrelapse survival. Future prospective studies should investigate optimal CSI doses and the role of salvage chemotherapy in this population.”
Craig Erker, MD, MS, of the Division of Hematology/Oncology, IWK Health Centre and Dalhousie University, Halifax, Canada, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: The study was supported by the IWK Health Centre Recruitment/Establishment Grant, Cancer Research UK, and Australian Lions Childhood Cancer Research Foundation. For full disclosures of the study authors, visit ascopubs.org.