Prevalence and Spectrum of Variants in Homologous Recombination Repair Genes in Ovarian Cancer in Latin America: A Systematic Review and Meta-analysis

Background Ovarian cancer is a major cause of gynecologic cancer mortality worldwide, with disproportionately poor outcomes in Latin America (LATAM). Variants in homologous recombination repair genes, especially BRCA1/2 , are predictive biomarkers for platinum-based chemotherapy and PARP inhibitors. However, data on the prevalence and spectrum of homologous recombination repair variants in LATAM populations remain limited. Objectives To synthesize the prevalence and spectrum of pathogenic and likely pathogenic variants in homologous recombination repair pathway genes among LATAM ovarian cancer patients and highlight clinical and research implications. Methods The review protocol was developed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and was registered in the international prospective register of systematic reviews (PROSPERO; registration number CRD420251019706). We systematically searched MEDLINE, EMBASE, Scopus, Web of Science, LILACS, Cochrane, and Epistemonikos through April 2025. Eligible studies included LATAM ovarian cancer patients tested with multigene panels covering homologous recombination repair genes beyond BRCA1/2 . Data extraction followed 2025 ACMG/AMP guidelines, and study quality was assessed with the Joanna Briggs Institute checklist. Pooled prevalence was estimated using random- and common-effects meta-analysis. Results Eight studies published between 2017 and 2023, including 442 patients with ovarian cancer from Brazil, Argentina, Mexico, Chile, and Colombia, were included in the systematic review. Following variant curation and reclassification, seven studies comprising 433 patients and 96 pathogenic/likely pathogenic homologous recombination repair variant carriers were retained for prevalence analysis, yielding a crude prevalence of 22.2%. Pathogenic variants predominated (91.7%), with BRCA1 (55.2%) and BRCA2 (40.6%) accounting for ∼96% of carriers. Non- BRCA homologous recombination repair variants ( CHEK2, BARD1, and RAD51D ) accounted for 4.2%. The pooled prevalence of germline pathogenic/likely pathogenic homologous recombination repair variants was 17% (95% CI, 9–26%; I² = 56.2%), increasing to 20% (95% CI, 16–23%; I² = 0%) after sensitivity analysis excluding two micro-cohorts. Five recurrent variants were identified across multiple cohorts and countries. No study evaluated somatic homologous recombination repair variants or homologous recombination deficiency assays Conclusions This first systematic synthesis of homologous recombination repair variants in LATAM ovarian cancer reveals a predominance of BRCA1/2 but also underscores the relevance of non- BRCA homologous recombination repair genes. Lack of somatic testing, methodological heterogeneity, and limited regional coverage highlight the need for standardized approaches, multicenter collaboration, and equitable access to genomic diagnostics in the region. Implications for Practice This systematic review highlights both opportunities and barriers for implementing homologous recombination repair testing in ovarian cancer across Latin America. While BRCA1/2 remains the predominant genes, non- BRCA variants are also clinically relevant. Importantly, we identified substantial inequities in the distribution of genomic testing capacity, with most data concentrated in Brazil and Argentina, leaving many countries unrepresented. The absence of somatic homologous recombination repair /homologous recombination deficiency testing and heterogeneous sequencing approaches further limit regional comparability and access to precision therapies. Addressing these disparities through standardized testing strategies and collaborative networks is critical to ensure equitable access to genetic counseling and targeted treatments.