Incidence of medulloblastoma in Canadian children.

Medulloblastoma is the most common malignant brain tumor in children. There was a perception of pediatric neuro-oncologists that the incidence had declined in Canada. An epidemiological survey was undertaken to determine the incidence of this tumor in Canada and if a change had indeed occurred. All patients 14 years and under diagnosed with medulloblastoma from 1990 to 2009 inclusive in Canada were included. Data collected included date of diagnosis, age at diagnosis, gender, stage, pathology, treatment, recurrence and current status. Data were analysed for change in incidence over time. Data were obtained on 574 eligible patients. The mean overall incidence per 1,000,000 persons was 4.82 (95 % CI 4.28-5.35) for the study time period. The mean age at diagnosis was 5.8 years, and there was a male predominance. Although there was an increase in incidence over the first three time periods (24 % for 1990-1994, 27.5 % for 1995-1999, 27.7 % for 2000-2004), the most recent time period (2005-2009) showed a decrease (21 %). This was true for male children while the incidence was stable for females. The mean incidence rate was double for children under the age of 5 years (7.92 per million) compared to those over 5 years (3.64 per million).This study showed that from 1990 to 2009 the incidence of medulloblastoma was relatively stable, with a slight decrease in the last five-year time period.