ERBB2 and breast carcinoma: Trials have shown that the Hormone‐Receptor (HR)‐positive and HER2/neu (Human Epidermal Growth factor receptor‐2)‐negative early‐stage breast cancer patients have sustained risk of recurrence over a period of 5‐20 years1, 2 and rates of distant recurrence in patients treated with endocrine therapy alone is 15% in the first 5 years.1