Unraveling the Resistance: Challenges and Advances in PARP Inhibitor Therapy for BRCA1/2 Breast Cancer.

Breast cancer is the most prevalent malignant tumor among women globally, with breast cancer susceptibility genes (BRCA1 and BRCA2, BRCA1/2) mutations significantly increasing the risk of developing aggressive forms of the disease. Poly (ADP-ribose) polymerase (PARP) inhibitors (PARPi) have shown promise in treating BRCA1/2-mutated breast cancer by exploiting deficiencies in homologous recombination (HR) repair. However, the emergence of acquired resistance poses a significant challenge. Our study examines the mechanisms of PARPi resistance in BRCA1/2-mutated breast cancer, synthesizing recent clinical advancements and identifying key resistance pathways, including HR recovery, DNA replication fork stability, and epigenetic modifications. We also highlight potential strategies to overcome these challenges to PARPi resistance, such as combination therapies and novel targets. Our comprehensive analysis aims to inform future clinical practices and guide the development of more effective treatment strategies.