ERBB2 and neoplasm: In the UK, the National Institute of Health and Care Excellence (NICE) recommends NET ‘as an option to reduce tumour size if there is no definite indication for chemotherapy’10 and in the USA the American Society of Clinical Oncology (ASCO) recommends that in postmenopausal patients with hormone receptor-positive and HER2-negative disease ‘neoadjuvant endocrine therapy with an aromatase inhibitor (AI) may be offered to increase locoregional treatment options’11.