Neuro Oncol. 2021 Mar 19:noab067. doi: 10.1093/neuonc/noab067. Online ahead of print.
INTRODUCTION: Global variations in survival for brain tumours are very wide when all histological types are considered together. Appraisal of international differences should be informed by the distribution of histology, but little is known beyond Europe and North America.
PATIENTS AND METHODS: The source for the analysis was the CONCORD data base, a programme of global surveillance of cancer survival trends, which includes the tumour records of individual patients from more than 300 population-based cancer registries. We considered all patients aged 0-99 years who were diagnosed with a primary brain tumour during 2000-2014, whether malignant or non-malignant. We presented the histology distribution of these tumours, for patients diagnosed during 2000-2004, 2005-2009, and 2010-2014.
RESULTS: Records were submitted from 60 countries on five continents, 67,331 for children and 671,085 for adults. After exclusion of irrelevant morphology codes, the final study population comprised 60,783 children and 602,112 adults. Only 59 of 60 countries covered in CONCORD-3 were included, because none of the Mexican records were eligible. We defined 12 histology groups for children, and 11 histology groups for adults. In children (0-14 years), the proportion of low-grade astrocytomas ranged between 6% and 50%. Medulloblastoma was the most common sub-type in countries where low-grade astrocytoma was less commonly reported. In adults (15-99 years), the proportion of glioblastomas varied between 9% and 69%. International comparisons were made difficult by wide differences in the proportion of tumours with unspecified histology, which accounted for up to 52% of diagnoses in children and up to 65% in adults.
CONCLUSIONS: To our knowledge, this is the first account of the global histology distribution of brain tumours, in children and adults. Our findings provide insights into the practices and the quality of cancer registration worldwide.