Global epidemiology of pheochromocytoma: a systematic review and meta-analysis of observational studies

Objective: The aim of this systematic review and meta-analysis of observational studies is to provide an overview of the global epidemiology of pheochromocytomas and to evaluate the quality of study reporting for the identified studies. Methods: Two bibliographic databases, PubMed and Embase, were searched for studies assessing the epidemiology of pheochromocytoma from inception until December 2024. Original observational studies written in English and reporting pheochromocytoma prevalence and/or incidence for a well-defined geographic area were included. Two reviewers independently screened the retrieved articles for inclusion, extracted relevant data, and carried out the evaluation of the quality of study reporting. A narrative synthesis of the results was provided, along with a meta-analysis of both prevalence and incidence of pheochromocytoma. Results: A total of 14 studies were included in the systematic review, of which 13 were included in the meta-analysis. The pooled prevalence of pheochromocytoma was 19.8 (95% CI: 9.6-40.8) cases per 1,000,000 individuals, and the incidence rate was 1.9 (95% CI: 1.2-2.6) cases per million person-years. Substantial between-study heterogeneity was observed for both prevalence and incidence rates (I2 = 98.7 for both), mainly due to different geographic areas and the use of different data sources. The quality of study reporting was rated as high for only one study, low for four studies, and medium for the remaining nine. Conclusions: Overall, our systematic review and meta-analysis of observational studies revealed significant between-study heterogeneity of prevalence of pheochromocytoma amounting to around 20 per million individuals. Establishing national registries using standardized diagnostic and clinical parameters, along with well-defined selection and analysis criteria, may provide better insight into the epidemiology and the course of this rare disease.