Purpose: Neoadjuvant systemic therapy with dual HER2-blockade, trastuzumab and pertuzumab, combined with chemotherapy has become a standard approach in patients with HER2-positive (HER2+) breast cancer (BC). However, the variability in treatment outcomes, such as pathological complete response (pCR) or relapse rates, underscores the need to identify predictive factors to optimize therapeutic strategies. This st...