Abstract 4948: Bladder cancer incidence: A systematic review and meta-analysis in SSA
Authors: Klovis Klifford Kabore, Samiratou Ouedraogo, Serge Somda, Andrew Donkor, Fasnewinde Aristide Kabore, Olga Lompo, Nicolas Meda
Journal: Cancer Research (2025)

Abstract Introduction: Bladder Cancer shows a substantial geographic disparity worldwide (1-3). The highest incidence rates are found in Europe, Asia and America (1). Overall, sub-Saharan Africa has low incidence rates (1). Despite low rates in Africa, disparities exist, and some countries in sub-Saharan Africa have incidence rates above the global average (4). Despite this vast population, bladder cancer burden in Africa is not currently well characterized, in part due to lack of data on incidence, prevalence and mortality. This systematic review estimated the incidence rate of bladder cancer in SSA and identified the common associated risk factors reported, based on available data. Methods: A systematic review was conducted and reported according to guidance provided in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (5, 6). A comprehensive search using research4life portal (Medline, Google Scholar, Embase, Scopus, African Journals Online) and other grey litterature were systematically searched from 1990 up to December 2023. We included population-based studies that reported the incidence and studies that reported risk factors of bladder cancer in Sub Saharian Africa. We excluded studies from any articles reporting on other cancer than bladder and any Articles from northern African countries. To perform the meta-analysis, we applied the random effects method to estimate the pooled incidence rate (7, 8). A narrative synthesis by Popay and colleagues was undertaken to identify the associated risk factors (9). Our primary Outcome measures Overall and sex-specific annual age-standardized incidence rates (ASIR) of bladder per 100 000 population and the secondary outcome identifies associated risk factors. Results: The meta-analysis included 20 studies. The overall ASIR of bladder cancer in Africa per 100 000 population was 3.90 (95% CI 1.83 to 5.96). The rates were 3.95 (95% CI, 2.63 to 5.26) in males and higher than rates found in females 1.89 (95% CI, 1.22 to 2.56), and significantly different. The narrative synthesis of 22 included articles generated five elements that were related to bladder cancer risk factors in SSA countries namely schistosomiasis, smoking, occupational exposure, chronic urinary tract infection as well as recurrent bladder stone regardless of how the association was assessed. Conclusion: This study highlights the lack of up-to-date data to estimate the incidence of bladder cancer and its associated factors in SSA over the last 10 years. Nevertheless, for the years prior to that bladder cancer estimates in Africa could be underestimated. Quality data collection systems such as population-based cancer registries may be helpful for accurate estimation of country-specific incidence rates. This would be important for better allocation of resources for early diagnosis, treatment and improving overall patient outcomes. Citation Format: Klovis Klifford Kabore, Samiratou Ouedraogo, Serge Somda, Andrew Donkor, Fasnewinde Aristide Kabore, Olga Lompo, Nicolas Meda. Bladder cancer incidence: A systematic review and meta-analysis in SSA [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 4948.