[A case of breast cancer with repeated cardiac dysfunction due to trastuzumab]

Here we present a case of breast cancer in which cardiac dysfunction had previously been observed on trastuzumab(TRS) administration; the condition then improved but reoccurred on readministration of TRS. A 52-year-old woman received preoperative chemotherapy for StageIIIC left breast cancer(fluorouracil, epirubicin and cyclophosphamide followed by docetaxel and TRS), and then underwent partial mastectomy and axillary lymph node dissection. For adjuvant therapy, she received endocrine therapy and TRS. Radiation therapy was administered to the left residual breast. The patient complained about palpitation in the 5th cycle of TRS, and left ventricle ejection fraction(LVEF)decreased to 45.3% from 64%. Therefore, we stopped TRS administration. Palpitation improved, and LVEF increased to 53% after 2 months. TRS was administered again; however, palpitation reoccurred and LVEF decreased to 44%. TRS administration was once again discontinued. However, according to the HERA trial report regarding patients with a history of anthracycline and radiation therapy, TRS administration could be resumed when LVEF is greater than 50%, but we should be more careful during readministration of TRS.