A Case of Asymptomatic Left Ventricular Dysfunction during the Treatment of Metastatic Breast Cancer with Trastuzumab

We report a case of 29-year-old Japanese female with a history of resection of primary carcinoma of the right breast. After a partial response by chemotherapy with pirarubicin and docetaxel for lung metastasis, the patient developed multiple brain and bone metastases. As the degree of overexpression of human epidermal growth factor receptor-2 (HER2) was (2+), trastuzumab was administered in combination with paclitaxel. Asymptomatic left ventricular (LV) systolic dysfunction evaluated by echocardiography was observed ten weeks after the beginning of the treatment. After two weeks of discontinuation of the therapy, however, LV function showed rapid recovery and the resumed use of trastuzumab did not cause further cardiac deterioration. The patient died of sudden respiratory failure due to cerebral herniation and not to heart failure