Combining PD-1/PD-L1 inhibitor and PARP inhibitor: a new perspective on the treatment of triple negative breast cancer

Compared with other types of breast cancer, triple negative breast cancer has a poor survival prognosis due to its high aggressiveness and lack of effective therapeutic targets. Immune checkpoint (PD-1/PD-L1 and CTL-4) inhibitors have emerged as a breakthrough therapy in the treatment in various metastatic cancers. PARP inhibitors promote DNA damage in tumor cells, not only promoting immune initiation through a series of molecular mechanisms, but also leading to adaptive upregulation of programmed death ligand 1 (PD-L1) expression. Therefore, the combination of the two inhibitors can improve the efficacy of tumor treatment. We reviewed the research progress of their combined use in triple negative breast cancer, and put forward relevant ideas for further development, hoping to find the best treatment mode of the combined use of the two.