ERBB2 and breast cancer: Different studies have shown that subcutaneous Trastuzumab (SC-TZM) can offer many advantages compared to intravenous Trastuzumab (IV-TZM) and that it is effective in the treatment of patients with early stage HER2-positive BC, according to the primary endpoints of pathologic complete response (absence of invasive neoplastic cells in the breast, remaining ductal carcinoma in situ) [10, 12, 13].