Inclusion Criteria:  HER2 positive breast cancer (hormone receptors positive or negative) Stage I to III Indication for neoadjuvant therapy with chemo (any regimen) + trastuzumab + pertuzumab Breast surgery after neoadjuvant therapy Preserved coagnition ECOG 0-3 For the randomization phase: pathological complete response (ypT0/ypTis and ypN0) Agreement on participation and signature of de ICF  Exclusion Criteria:  Contradindication for trastuzumab or pertuzumab Adjuvant chemotherapy. Hormone therapy is allowed Second primary tumor < 5 years, with an exception for treated non-melanoma skin cancer, and in situ cervical cancer