Breast cancer remains one of the most prevalent malignancies affecting women worldwide and continues to be a leading cause of cancer-related morbidity and mortality. Patients may present with either localized or advanced disease, with clinical outcomes increasingly influenced by molecular subtype and genetic profile. This review highlights the key genetic factors involved in breast cancer, current diagnostic and therapeutic strategies, and promising emerging approaches that may shape future clinical management. Breast cancer diagnosis typically involves clinical breast examination, imaging techniques such as mammography and ultrasound, and confirmatory biopsies. Genetic mutations in specific genes are strongly linked to the development, progression, and metastasis of the disease. Treatment options for localized breast cancer continue to include surgery (lumpectomy or mastectomy) and radiotherapy, combined with systemic therapies tailored to tumor biology, such as endocrine therapy, human epidermal growth factor receptor 2 (HER2)-targeted therapy, and cyclin-dependent kinase (CDK)4/6 inhibitors. For advanced or metastatic breast cancer, recent therapeutic advances include the use of immunotherapy (e.g., immune checkpoint inhibitors), Poly (ADP-ribose) polymerase (PARP) inhibitors for Breast Cancer gene (BRCA)-mutated cancers, antibody–drug conjugates, and novel targeted agents, which have significantly improved patient outcomes in selected populations. Recent findings in breast cancer genetics have highlighted the critical role of germline and somatic mutations, particularly in genes such as BRCA1, BRCA2, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), and TP53, in driving tumor initiation, progression, and therapeutic response. Molecular profiling and next-generation sequencing technologies have enabled more precise tumor classification and facilitated the development of personalized treatment strategies. Despite these advances, treatment resistance and disease recurrence remain major challenges, particularly in aggressive subtypes such as triple-negative breast cancer. Consequently, ongoing research is exploring alternative and complementary approaches, including nanotechnology-based drug delivery systems, gene editing techniques such as clustered regularly interspaced short palindromic repeats-Cas9 (CRISPR-associated protein 9) (CRISPR-Cas9), cancer vaccines, and the integration of traditional and plant-derived compounds. These strategies aim to enhance therapeutic efficacy, reduce systemic toxicity, and overcome resistance mechanisms.

Introduction: BRCA1 is a tumor suppressor gene involved in DNA repair, genomic stability, and cell cycle regulation. The BRCA1 single nucleotide polymorphisms (SNPs) rs799917 and rs1799966 have been widely investigated for their association with breast cancer (BCa) risk, with inconsistent and population-specific findings. However, their frequency and clinical relevance in Nigerian populations remain poorly characterized. This study evaluated their association with BCa risk in Nigerian women and interpreted these findings within a global context of allele frequency variation. Methods: This prospective case-control study recruited 379 BCa cases and 196 age-matched controls. The samples were genotyped for BRCA1 rs799917 (A/G) and rs1799966 (C/T) using TaqMan real-time polymerase chain reaction (PCR). Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Allele frequencies from population-specific datasets in the database of single nucleotide polymorphism (dbSNP) were extracted and combined in a meta-analysis to compare variant distribution across global populations. Results: No significant association was observed between BRCA1 variants (rs799917 and rs1799966) and BCa risk in this cohort. Genotype distributions were comparable between cases and controls, and none of the tested genetic models reached statistical significance. Meta-analysis revealed marked inter-population variation in allele frequencies. Africans showed the lowest frequency of the rs799917 G allele (13.8%), and the highest frequency of the A allele (86.36%), whereas Europeans showed the highest G allele frequency (65.92%). For rs1799966, Africans had the lowest C allele frequency (20.17%) and highest T allele frequency (79.8%), while Asians showed the highest C frequency (38.25%). Conclusion: BRCA1 variants rs79917 and rs1799966 were not associated with BCa susceptibility in this Nigerian cohort. The observed inter-population differences in allele frequencies highlight the importance of genetic diversity in understanding BCa risk.