In conclusion, the importance of comparing chemotherapy regimens in a real-world population with either lower-risk breast cancer or increased frailty, assessing the relative benefits and toxicity of a chosen chemotherapy regimen is essential, particularly in patients with low-risk HER2-positive disease, which are underrepresented in the pivotal randomized adjuvant trials [14,15]. This evidence concerns the gene ERBB2 and breast carcinoma.