The aim of this study was to examine the possible association between CNVs in five genes related to the PI3K/AKT pathway, HER2, FGFR1, PIK3CA, AKT3 and MDM2, and the efficacy of anti-HER2 blockade neoadjuvant treatment in patients with early HER2-positive BC. This evidence concerns the gene PIK3CA and breast cancer.