ERBB2 and breast cancer: This study demonstrated no significant difference during years 5-10 in the outcome between HR+/HER2+ and HR-/HER2+ breast cancers treated with adjuvant trastuzumab (HR = 1.62, 95% CI: 0.97-2.71, p = 0.065), although a higher risk of recurrence was assessed in patients with HR+/HER2+ BC and N3 disease (adjusted HR = 4.39, 95% CI: 0.94-20.50, p = 0.06).