Canadian brain cancer survival rates by tumour type and region: 1992-2008.

objectivesTo investigate patterns of survival among brain cancer patients in Canada.

methodsCanadian Cancer Registry data were obtained for all patients with first-ever primary malignant brain tumours diagnosed between 1992 and 2008 (n = 38,095). Follow-up ended with patient death or December 31, 2008, whichever occurred first. Crude Kaplan-Meier estimates were calculated at one, two and five years post-diagnosis. Cox proportional hazard models were used to obtain adjusted hazard ratios by region for major histology types. A time-specific generalized linear model was used to obtain 5-year survival estimates for specific age group, sex and region for major histology types.

resultsThe overall five-year survival rate was 27%. No significant difference in survival rate over time is observed. The highest 5-year survival rate was 65% (95% CI: 62.5%-67.4%) for oligodendrogliomas and the lowest was 4.0% (95% CI: 3.7%-4.3%) for glioblastomas. Compared to Ontario, the adjusted 5-year glioblastoma survival estimates were lower in British Columbia, Alberta and the Prairie provinces (Manitoba and Saskatchewan), while the survival estimates were lower in all other regions for diffuse astrocytoma, and lower in Manitoba and Saskatchewan for anaplastic astrocytomas. Estimates were significantly higher for oligodendrogliomas in Alberta, and for anaplastic oligodendrogliomas in Alberta and Quebec (p < 0.05).

conclusionThese data are consistent with previous literature in observing higher survival rates at younger ages, in female patients and for tumours with mixed oligo components. There is a need to further explore the underlying reasons for the observed variation in survival rates by region in an effort to improve the prognosis of brain cancer in the Canadian patient population.