Molecular Genetics of Breast Cancer: From Mechanistic Insights to the Therapeutic Approaches

Breast cancer is the second most common malignancy in US women, with 3.8 million affected, and 300,590 new cases were expected in 2023. Survival rates have improved due to advancements in diagnostic and treatment modalities, with noninvasive breast cancer showing 90% and 84% survival rates at 5 and 10 years, respectively. Risk factors for breast cancer include genetic alterations, lifestyle factors, and hormonal influences. Classification of breast cancers into intrinsic subtypes has improved early detection accuracy. Genetic testing plays a crucial role in risk assessment and prevention, with mutations in genes like BRCA1 and BRCA2 increasing cancer risks. High- and moderate-penetrance gene alterations in TP53, PTEN, CDH1, ATM, CHEK2, PALB2, RAD51C, RAD51D, NF1, and MSH6 cause 20–25% breast cancer risk. Population-based genetic studies have enhanced risk detection and understanding of breast cancer subtypes. Functional genomics and polygenic risk scores are essential for identifying target genes and predicting risk. Current treatments for breast cancer include chemotherapy, targeted therapy, and immunotherapies, with ongoing research focusing on improving long-term benefits for patients.