Treatment of adult nonmetastatic medulloblastoma patients according to the paediatric HIT 2000 protocol: a prospective observational multicentre study

BACKGROUND: Medulloblastoma in adulthood is rare. Knowledge is limited, and the efficacy and toxicity of chemotherapy--especially in nonmetastatic disease--is still elusive.

METHODS: Seventy adults aged ≥21 years (median age: 28.5 years) with nonmetastatic medulloblastoma were followed as observational patients within the prospective paediatric multicentre trial HIT 2000. Treatment consisted of radiotherapy (35.2 Gy to the craniospinal axis and a boost to 55.2 Gy to the posterior fossa) followed in most patients by maintenance chemotherapy (lomustine (CCNU), vincristine and cisplatin, n=49).

RESULTS: The implementation of maintenance chemotherapy was feasible. Peripheral neuropathy (74%) and haematotoxicity (55%) during maintenance chemotherapy appear to be more common in adults than in children. At a median follow-up of 3.7 years, the 4-year event-free survival (EFS) and overall survival (OS) rates±standard error (SE) were 68%±7% and 89%±5%. Patients with desmoplastic medulloblastoma and lateral tumour location (n=19) had a lower EFS compared to patients with centrally located desmoplastic tumours (n=10) (p=0.011). Absence of residual postoperative tumour (n=40) was associated to a lower rate of progression/relapse compared to present (n=11) or unknown (n=12) residual tumour status (p=0.006). Lateral tumour location and unknown residual tumour status were independent negative prognostic factors.

CONCLUSIONS: Maintenance chemotherapy is applicable in adults with nonmetastatic medulloblastoma. Histological subtype and tumour location were newly identified risk factors in this age-group, and should be further analysed in prospective trials.