Topic: Genomic Landscape of Hereditary Breast Cancer: Unraveling Novel Genetic Markers

Almost three decades have passed since the discovery of BRCA1 and BRCA2, the main genes associated with hereditary breast cancer. Since then, a multitude of other susceptibility genes have been uncovered, each exerting unique influences on the lifetime risk of developing breast cancer. Notably, high-to-moderate penetrance alleles, particularly within genes involved in DNA double-strand break repair via homologous recombination (HR), have been identified, largely thanks to the widespread adoption of high-throughput technologies, especially next-generation sequencing (NGS), in both research and clinical contexts. 

The mutation status of BRCA1/BRCA2 has also emerged as a predictive biomarker in the treatment of breast cancer patients using PARP inhibitors in routine clinical practice. Additionally, other genetic defects in HR and DNA repair pathways may contribute to inherent or acquired sensitivity to PARP inhibitors. Thus, while expanding our understanding of genetic factors in breast cancer is crucial for more effective risk assessment and management in familial cases, some of these genetic alterations may also serve as predictive biomarkers for targeted molecular therapies.

The utilization of omics technologies has currently facilitated the comprehensive profiling of breast cancer, profoundly influencing our understanding of breast cancer biology and offering data with potential clinical implications.

The objective of this Special Issue is to provide updated insights into the genomic landscape of hereditary breast cancer, aiming to uncover biomarkers predictive of cancer risk and treatment response, representing a fundamental step toward precision oncology for breast cancer patients.