Approximately 10%-20% of tumours overexpress HER2, which is associated with poor clinical outcome, including a 15%-25% risk of recurrence.4, 5, 6, 7, 8 Locoregional surgery, radiotherapy and systemic therapy (neoadjuvant chemotherapy, HER2-targeted therapy or endocrine therapy) are part of the treatment algorithm for HER2-positive EBC. This evidence concerns the gene ERBB2 and neoplasm.