Evidence of high mortality in long term survivors of childhood medulloblastoma.

The diagnosis of pediatric medulloblastoma now carries a much improved overall survival; however as outcomes advance, late mortality, from causes such as disease recurrence and subsequent malignancies, are of increasing concern for these patients. Using the Surveillance, Epidemiology, and End Results database, the causes of late mortality in long term survivors of medulloblastoma were evaluated. Patients diagnosed with a medulloblastoma between the ages of 0-19 years who survived at least 5 years after diagnosis were included. Using U.S. population data, standardized mortality ratios (SMRs) were calculated. Cumulative incidence estimates and standardized incidence ratios (SIRs) of subsequent malignancies were calculated. A total of 455 patients were included in the analysis. All patients received radiation as part of therapy. Median age at diagnosis was 7 years, and mean follow-up was 16 years. By the time of last follow-up, 20.4 % of patients had died, representing an SMR of 24.0 (95 % CI 19.3-29.4). Overall survival at 30 years was 65.5 %. Primary recurrence accounted for 59 % of late deaths, while subsequent malignancy accounted for 11.8 %. SIR for subsequent malignancy in these patients was 10.4 (95 % CI 6.9-15.1). The most common secondary tumor was another brain tumor (32 %), followed by thyroid cancer (21 %). These data demonstrate that late mortality remains a significant problem in these patients. The causes of death are largely attributable to disease recurrence and secondary malignancies. Efforts to improve risk stratification and tailor therapy will help in reducing late mortality in this population.