Precision targeted therapy and immunotherapy in breast cancer: Advances and clinical frontiers

ABSTRACT: Breast cancer remains the most common cancer among women worldwide, characterized by significant molecular heterogeneity. Advances in targeted therapy and immunotherapy have transformed treatment approaches, offering promising new options for patients. Targeted therapies are designed to inhibit the key pathways that drive tumor growth and survival. The cyclin-dependent kinase 4/6 (CDK4/6) inhibitors, phosphatidylinositol-3 kinase (PI3K) inhibitors, mammalian target of rapamycin (mTOR) inhibitors, and other treatments have significantly advanced treatment, delaying progression and extending survival for some subtypes of breast cancer. Nevertheless, targeted therapeutic agents have not yet demonstrated significant clinical efficacy in the treatment of triple-negative breast cancer (TNBC). Meanwhile, immunotherapy has emerged as a complementary approach. Immune checkpoint inhibitors (ICIs) have demonstrated notable efficacy in subsets of TNBC and are under exploration in other breast cancer subtypes, including hormone receptor positive/human epidermal growth factor receptor 2 negative (HR+/HER2-) and HER2-positive disease. Furthermore, innovative strategies such as anticancer vaccines and adoptive T-cell therapy offer potential for prolonged immune engagement and tumor eradication. This review provides an overview of current progress in targeted therapies and immunotherapy for breast cancer, highlighting their mechanisms, clinical utility, and challenges. By integrating knowledge from recent advancements, this review seeks to guide future research and clinical practice toward improved and personalized care for breast cancer patients.