To investigate the utility of postoperative chemotherapy in delaying radiotherapy and to identify prognostic factors in early childhood medulloblastoma, we studied children younger than 3 years of age registered to the HIT-SKK'87 (Therapieprotokoll für Säuglinge und Kleinkinder mit Hirntumoren [Brain Tumor Radiotherapy for Infants and Toddlers with Medulloblastoma] 1987) trial who received systemic interval chemotherapy until craniospinal radiotherapy was applied at 3 years of age or at relapse, from 1987 to 1993. Children with postoperative residual tumor or metastatic disease received systemic induction chemotherapy prior to interval chemotherapy. Twenty-nine children were eligible for analyses (median age, 1.7 years; median follow-up, 12.6 years). In children without macroscopic metastases, rates (+/-SEM) for 10-year progression-free survival (PFS) and overall survival (OS) were 52.9% +/- 12.1% and 58.8% +/- 11.9% (complete resection), and 55.6% +/- 16.6% and 66.7% +/- 15.7% (incomplete resection), compared with 0% and 0% in children with macroscopic metastases. Survival was superior in nine children with desmoplastic or extensive nodular histology compared with 20 children with classic medulloblastoma (10-year PFS, 88.9% +/- 10.5% and 30.0% +/- 10.3%, p = 0.003; OS, 88.9% +/- 10.5% and 40.0% +/- 11.0%, p = 0.006). Eleven of 12 children with tumor progression during chemotherapy had classic medulloblastoma. After treatment, IQ scores were inferior compared with nonirradiated children from the subsequent study, HIT-SKK'92. Classic histology, metastatic disease, and male gender were independent adverse risk factors for PFS and OS in 72 children from HIT-SKK'87 and HIT-SKK'92 combined. In terms of survival, craniospinal radiotherapy was successfully delayed especially in young children with medulloblastoma of desmoplastic/extensive nodular histology, which was a strong independent favorable prognostic factor. Because of the neurocognitive deficits of survivors, the emerging concepts to avoid craniospinal radiotherapy should rely on the histological medulloblastoma subtype.
