[A Case in Which Re-Administration of Pertuzumab/Trastuzumab with Eribulin Therapy Was Useful for Recurrent HER2 Breast Cancer].

Pertuzumab plus trastuzumab plus docetaxel regimen is the first choice for the initial treatment of HER2-positive recurrent breast cancer. However, docetaxel causes many adverse events. A 48-year-old woman was admitted to our hospital for a left breast tumor and was diagnosed with left breast cancer(T1N0M0, Stage Ⅰ, Luminal A). We performed a breast-conserving surgery and sentinel lymph node biopsy, followed by irradiation of the remaining parts of the mammary gland and adjuvant therapy with tamoxifen. Three and a half years after the first surgery, she underwent local resection due to chest wall recurrence of breast cancer. The recurrent tumor was HER2-positive, and we administered fluorouracil, epirubicin, cyclophosphamide( FEC)and paclitaxel plus trastuzumab. Liver metastases were confirmed on completion of cycle 11 of trastuzumab administration, and the regimen was changed to pertuzumab plus trastuzumab plus docetaxel. A partial response was seen following this regimen. The next line of treatment was the administration of 5 cycles of T-DM1, which resulted in stabilizing the disease. The liver metastases progressed, and the regimen was changed to pertuzumab plus trastuzumab plus eribulin. Partial response was seen following this regimen for liver metastases without serious adverse events(20 cycles).