Challenges in determining the global burden of non-malignant central nervous system tumors: An analysis of international incidence and mortality data sources

BACKGROUND: Non-malignant tumors of the CNS contribute substantially to the morbidity and mortality from CNS tumors. It is critical to understand the epidemiology of non-malignant CNS tumors separately from CNS malignancies to inform resource allocation and policy since treatment and prognosis can differ. High-quality international data on non-malignant CNS tumor burden are needed to accomplish this goal. METHODS: We assessed the cancer registry and vital registration data available to the Global Burden of Disease study by its inclusion of non-malignant CNS tumors, reporting on the availability of data over time and by the World Bank income group. We analyzed preliminary age-standardized incidence rates (ASIRs), age-standardized mortality rates (ASMRs), and proportions of CNS tumors by behavior for adults, children, and all ages. RESULTS: Non-malignant CNS tumors were reported separately in 17.2% (N = 66) of registry reports and in aggregate with malignant CNS tumors in 18.0% (N = 69) of reports. Only 7 low- and middle-income countries (LMICs) had data reporting CNS tumors separately by behavior. Across all ages combined, the median ASIR of non-malignant CNS tumor data was 0.31 (interquartile range: 0.15-0.50) and ASMR was 0.24 (0.10-0.44) per 100,000 in LMICs compared to median ASIR of 3.62 (2.62-4.97) and ASMR of 0.32 (0.16-0.65) in high-income countries (HICs). A larger proportion of incident CNS tumors were reported as non-malignant in HIC data than LMIC data (P < .0001). CONCLUSIONS: Our study alludes to current challenges in understanding global non-malignant CNS tumor burden and a need for increased international data collection. Further research is needed to comprehensively investigate opportunities for future data inclusion.