ERBB2 and breast cancer: Olaparib has demonstrated improved progression-free survival (PFS) in placebo-controlled phase III studies in BRCA-mutated ovarian cancer [23, 24] and prolonged PFS in a phase III trial of patients with human epidermal growth factor receptor 2 (HER2)-negative breast cancer with a germline BRCA1/2 mutation compared to standard-of-care treatment [16].