Long-term outcome of posterior fossa medulloblastoma in patients surviving more than 20 years following primary treatment in childhood

Abstract

The aim of the study was to analyze the long-term outcome (>20 years) after treatment of posterior fossa medulloblastoma (MB) in childhood. We analyzed data from patients treated for posterior fossa MB between 1974 (introduction of the first international treatment protocol in Norway) and 1987 (when use of radiotherapy was abandoned in children under 4 years of age). Out of 47 children, 24 survived >20 years. At the time of analysis, 16 patients (median age 41 years, range 32-52) were alive (median follow-up 34 years, range 30-42), while 8 patients died 22-41 years (median 31 years) after primary treatment: one late death (after 22 years) was due to tumor recurrence whilst other 7 deaths (after 23 to 41 years) were related to the detrimental effects of the treatment (secondary tumors, stroke, severe epilepsy and depression). Observed 20- and 30-year survival rates were 51% and 44%, respectively. Despite successful treatment of MB in childhood and satisfactory tumor control during the first 20 years following primary treatment, our data indicates that even long-term survivors may die from tumor recurrence. However, the main factors causing late mortality and morbidity in long-term survivors seem to be the complications related to radiotherapy given in childhood.

Figure 1

(a) Kaplan-Meier curve presenting observed survival for children treated for posterior fossa medulloblastoma between 1974 and 1987 (n = 47). Patients included in the present study (n = 24), i.e. surviving >20 years, are those right to the dotted line on the abscissa. (b) Kaplan-Meier curve from the publication of Helseth et al. where also some patients from the present study were included, although at that point of time with a mean observation time of only 13.5 years. The decline in survival after 20 years of observation could therefore not be anticipated at the time of this previous publication.