Mapping the Prevalence of BRCA1 and BRCA2 Mutations in Hereditary Breast and Ovarian Cancer Across Africa: A Systematic Review and Meta-Analysis

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BACKGROUND: BRCA1 and BRCA2 gene mutations are major contributors to hereditary breast and ovarian cancer syndrome (HBOC). While mutation prevalence has been well-characterized in high-income countries, African populations remain underrepresented in genomics cancer research. Accurate prevalence data are essential for informing targeted screening, counselling, and personalized treatment strategies across the continent. OBJECTIVE: To systematically assess the prevalence and geographic distribution of pathogenic BRCA1 and BRCA2 mutations in African populations affected by HBOC, and identify opportunities to enhance genetic testing and clinical integration. METHODS: A systematic review and meta-analysis were conducted in accordance with PRISMA guidelines. PubMed, Scopus, Web of Science, and Embase were searched for studies published between January 2000 and June 2024. Studies were eligible if they reported germline BRCA1 or BRCA2 mutation data in African individuals with breast and/or ovarian cancer. Two reviewers independently screened studies, extracted data, and assessed methodological quality. Meta-analyses were performed using STATA 18 and RevMan, with fixed-effects models applied. Heterogeneity was evaluated using the I² statistic, and subgroup analyses were conducted based on gene type. RESULTS: A total of 52 studies from 19 African countries were included. Most studies originated from Morocco (28.4%), Tunisia (18.9%), South Africa (14.7%), and Nigeria (11.6%). Cross-sectional designs were most common (68.4%). Sanger sequencing was used in 45.3% of studies, followed by next-generation sequencing (31.6%). The overall pooled prevalence of pathogenic BRCA1/2 mutations was 9.0% (95% CI: 7.7-10.4%). Subgroup analyses showed a higher prevalence for BRCA1 mutations (10.5%, 95% CI: 8.3-13.0%) compared to BRCA2 (5.5%, 95% CI: 4.9-6.1%). Over half of the studies did not distinguish between the two genes, highlighting a need for standardized gene-specific reporting. CONCLUSION: There is a significant burden of pathogenic BRCA mutations in African HBOC populations, particularly BRCA1. However, gaps in geographic coverage and inconsistent reporting suggest the true burden may be underestimated. Expanding access to genetic testing, improving reporting standards, and integrating hereditary cancer screening into public health strategies are critical steps to advance precision oncology across Africa.

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