IARC 60th Anniversary - 19-21 May 2026
Session : 19/05/26 - Posters
PREVALENCE OF HEREDITARY GENE MUTATIONS IN CAPE VERDEAN BREAST CANCER PATIENTS
BORGES P. 1,6, SPENCER H. 2, PEREIRA C. 7, FURTADO S. 1, SANTOS C. 5, PINTO C. 5, TEIXEIRA M. 5, LARA SANTOS L. 5
1 Molecular Biology Laboratory, Agostinho Neto University Hospital, Praia, Cabo Verde; 2 Oncology Unit, Agostinho Neto University Hospital, Praia, Cabo Verde; 3 Experimental Pathology and Therapeutics Group - Research Center, Portuguese Oncology Institute of Porto (IPO Porto), Porto, Portugal; 4 Surgical Oncology Department, Portuguese Institute of Oncology, Porto, Portugal; 5 Genetic laboratory- IPO Porto Research Center (CI-IPOP), Instituto Português de Oncologia do Porto, Porto, Portugal; 6 Clinical Research and Innovation Center, Agostinho Neto University Hospital, Praia, Portugal; 7 Garcia de Horta Hospital, Lisbon, Portugal
OBJECTIVE:The study aims to identify and characterize the spectrum of hereditary gene variants in Cape Verdean breast cancer patients through multigene panel testing. Additionally, it seeks to evaluate the prevalence of specific genes variations, develop and inform strategies for optimizing the management of patients with increased genetic risk or at-risk patients.
METHODS: A total of 625 breast cancer patients diagnosed at Agostinho Neto University Hospital (ANUH) were reviewed. Of these, 315 met criteria for referral for Hereditary Breast and Ovarian Cancer (HBOC) testing based on age, TNBC status, family history, or male sex. Peripheral blood samples were collected from 155 patients; 119 were analyzed using Next Generation Sequencing (NGS) with the TruSight V2 panel on a NextSeq™ 550 Dx platform. Data analysis, variant calling, and interpretation were performed using NextGENe, Geneticist Assistant, Integrated Genome Browser, GeneMarker software, and classification based on ClinVar. Additionally, six patients with prior genetic testing were included.
RESULTS:A total of 625 breast cancer patients were identified at ANUH, and 315 met at least one criterion for hereditary breast cancer (HBC) referral: 181 were under 45, 79 had TNBC, 8 were male, and 74 had a family history. Genetic testing was conducted on 119 patients plus six previously tested elsewhere. Among the 125 tested, 23.2% (29/125) had a hereditary mutation. BRCA2 was the most frequently mutated gene (51.7%), followed by RAD51D (17.9%), BRCA1 and RAD51C (13.8% each), BRIP1 and PMS2 (3.5% each). A recurrent pathogenic BRCA2 variant (NM_000059.4.632-3C>G) was found in 12 cases, mostly from Santiago Island, suggesting a possible founder effect.
CONCLUSIONS:This first genetic profiling study of breast cancer in Cape Verde reveals a high prevalence of hereditary mutations, particularly in BRCA2. These findings highlight the urgent need for implementing genetic screening and counseling strategies to improve early detection and risk management for patients and their families.
IMPLICATIONS FOR PRACTICE AND POLICY:
The high prevalence of hereditary mutations, particularly in BRCA2, supports the integration of genetic testing and counseling into the breast cancer care routine in Cape Verde. The identification of a recurrent BRCA2 pathogenic variant suggests a possible founder effect, enabling the development of targeted and cost-effective screening strategies. These findings support risk-adapted surveillance, personalized treatment, and cascade testing of relatives. At the policy level, the results provide evidence to inform national guidelines for hereditary cancer screening, strengthen genomic diagnostic capacity, and support population-based cancer prevention strategies.