A critical appraisal of the quality of data submitted by sub-Saharan African cancer registries to GLOBOCAN 2020

Objectives (a) To critically appraise the quality of data submitted by sub-Saharan African (SSA) cancer registries to GLOBOCAN 2020 and (b) compare the quality of data of the registries common to GLOBOCAN 2008 and 2020. Design Critical appraisal of cancer registry data quality using the Parkin and Bray framework. Setting and Participants GLOBOCAN 2020 cancer registry estimates for 46 countries in SSA. Forty-three registries in 31 (SSA) countries were identified from the GLOBCAN 2020 supplementary documents, of which data from 28 registries in 23 sub-Saharan African countries were publicly available. Main outcomes measures Data quality for 15 variables in four domains (comparability, validity, timeliness and completeness) were appraised using the Parkin and Bray framework. Results from the appraisal of GLOBOCAN 2020 sources were compared with previous findings for GLOBOCAN 2008. Results Compared with GLOBOCAN 2008, GLOBOCAN 2020 country coverage had increased from 21 to 31 countries with 15 countries having no established registries. Out of a total possible score of 15 for data quality, 18 of the 28 publicly available GLOBOCAN 2020 registries fulfilled a score of 5 or more compared with seven registries in GLOBOCAN 2008. Of the 17 registries common to GLOBOCAN 2008 and 2020, nine showed an improvement in data quality. Conclusion Country coverage and data quality have improved since GLOBOCAN 2008, however, overall data quality and coverage remain poor. GLOBOCAN 2020 estimates should be used with caution when allocating resources.