REGIONAL DIFFERENCES IN THE SURVIVAL EXPERIENCE OF PATIENTS WITH CENTRAL NERVOUS SYSTEM TUMOURS IN CANADA

Health care in Canada is delivered on a provincial or territorial level. The objective of our population-based study was to investigate regional differences in survival among Canadians diagnosed with central nervous system (CNS) tumours. We identified 50,670 patients diagnosed with a first-ever primary CNS tumour between 2008 and 2017 with follow-up until December 31, 2017 (excluding Quebec) from the Canadian Cancer Registry linked to vital statistics. We selected the four highest incidence histologies and used Cox proportional hazards regression to estimate hazard ratios (HRs) for regions in Canada (British Columbia, the Prairie provinces, Ontario, the Atlantic provinces, and the Territories) adjusting for sex and tumour behaviour (malignant vs. non-malignant), and stratified by patient age. Ontario was the reference region and had the best survival profile for all histologies investigated. The Atlantic provinces had the highest HR for glioblastomas (HR=1.26, 95% CI:1.18-1.35), gliomas not otherwise specified (NOS) (Overall: HR=1.87, 95% CI:1.43-2.43; Pediatric population: HR=2.86, 95% CI:1.28-6.39) and unclassified tumours (HR=1.95, 95% CI:1.63-2.34). For meningiomas, the Territories had the highest HR (HR=2.44, 95% CI:1.09-5.45) followed by the Prairie provinces (HR=1.52, 95% CI:1.38-1.67). Our findings suggest that regional differences in survival may exist for patients with specific histological subtypes of CNS tumours at the population level. Whether the differential capture of non-malignant tumours across regions, tumour misclassification, or both contributes to the observed regional survival differences warrants further investigation.