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

Abstract 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 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 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 seven 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 across were reported as non-malignant in HIC data than LMIC data (p<0.0001). 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.