Sparing the gonadotoxicity of anthracyclines and cyclophosphamide in premenopausal women would be of great importance and is the standard of care in low risk HER2-positive breast cancer [28], but further studies are needed to refine the selection of patients with other tumor subtypes or with HER2-positive disease but at higher risk of recurrence that can be candidates to such de-escalated approach. This evidence concerns the gene ERBB2 and breast cancer.