Histology predicts a favorable outcome in young children with desmoplastic medulloblastoma: a report from the children's oncology group.

BACKGROUND: Contemporary therapy for medulloblastoma results in adverse neurocognitive effects on young children, particularly those under the age of 3. Stratification of patients by risk group may allow toxic treatment to be avoided.
METHODS: Seventy-six patients diagnosed with medulloblastoma and enrolled on CCG-9921 underwent central review of pathology, and histologic subtype was designated as desmoplastic or nondesmoplastic. Nonparametric event-free survival (EFS) and survival (OS) curves were computed using the product limit (Kaplan-Meier) estimates, and the log-rank test was used to compare survival according to histologic subtype.
RESULTS: Patients with desmoplastic medulloblastoma experienced a favorable EFS of 77% ± 9% and OS of 85% ± 8% compared with EFS of 17% ± 5% and OS of 29% ± 6% for patients with tumors in the nondesmoplastic group (P < .0001 for both EFS and OS comparisons). Patients without disease progression did not receive radiation therapy.
CONCLUSIONS: Children less than 3 with desmoplastic histology of medulloblastoma represent a lower-risk group for whom reduction of therapy, including elimination of radiation therapy, is an appropriate strategy.