[A Case in Which an Immune Checkpoint Inhibitor Responded to TN Breast Cancer with a History of Leukemia and Acquired pCR].

A 42-year-old women was refer with a left breast tumor. Mammography reveals category 4 tumor and breast sonography showed a tumor on her upper lateral portion with axillary and intra-thoracic mammary lymph node metastases. We treated by KEYNOTE-522 regimen that may proofed best effective for triple negative breast cancer(TNBC). Because of past history treating acute lymphatic leukemia, which had to regulate the amount of doxorubicin. But in this case acquired pCR with no adverse effects. In this report we experienced a case of TNBC with a history of leukemia treated by immune check point inhibitor. Even though, a case with regulated use of chemotherapy, immune checkpoint inhibitor revealed effective for a high risk TNBC.