A Locally Advanced Breast Cancer that Achieved pCR with Pertuzumab, Trastuzumab and Docetaxel: Case Report.

We herein report a case of locally advanced human epidermal growth factor receptor 2 (HER2)-positive breast cancer that achieved a pathological complete response (pCR) with pertuzumab, trastuzumab and docetaxel therapy. A 70-year-old female presented with an elastic hard mass, 5.0 cm in diameter with broad redness and edema of the skin in her right breast. Swollen lymph nodes were also recognized in the right axilla. The pathological diagnosis was invasive ductal carcinoma and its biological character was estrogen receptor (ER)-negative, progesterone receptor (PgR)-negative, HER2 3+ and Ki-67 index 60%. The patient was finally diagnosed with primary unresectable, locally advanced breast cancer and started on pertuzumab, trastuzumab and docetaxel combination therapy. The tumor subsequently reduced in size and, after 4 cycles of this therapy, she underwent surgery. The histopathological examination of the postoperative specimen showed pCR in both the primary tumor and axillary lymph nodes.