[Two Cases of Advanced HER2-Positive Locally Advanced Breast Cancer for Which Preoperative Chemotherapy with Pertuzumab, Trastuzumab, and Docetaxel Resulted in Good Response].

Case 1: A 68-year-old woman was diagnosed with advanced HER2-positive breast cancer(T2N2aM0, cStage ⅢA). She was treated with 4 courses of preoperative chemotherapy with pertuzumab, trastuzumab, and docetaxel. She was diagnosed to have achieved partial remission(PR), and subsequently underwent a mastectomy and axillary dissection. Pathological examination revealed smaller than 1 mm(Grade 2b). Case 2: A 59-year-old woman was diagnosed with advanced HER2-positive breast cancer(T4bN1M0, cStage ⅢB). She was treated with 4 courses of preoperative chemotherapy with pertuzumab, trastuzumab, and docetaxel. She was diagnosed to have achieved PR(primary lesion: complete remission), and subsequently underwent a mastectomy and axillary dissection. Pathological examination revealed complete pathological response(Grade 3). Combination therapy with pertuzumab, trastuzumab, and docetaxel appears to be a useful preoperative chemotherapy regimen for locally advanced HER2-positive breast cancer.