Pathological Complete Response To Neoadjuvant Trastuzumab And Pertuzumab Therapy Is Dependent On Her2/Cep17 Ratio In Her2-Positive Breast Cancer

Background. HER2 is amplified approximately 20% of breast cancers and HER2 receptor targeting therapy is associated with a significant improvements in disease-free and overall survival. In NeoSphere and TRYPHAENA clinical trials, the pathologic complete remission (pCR) rate was significantly increased when combined with pertuzumab and trastuzumab treatment. Although the efficacy and safety of anti-HER2 dual blockade therapy has been reported, the markers that predict the response are still unclear. This study aimed to investigate the relationship between the HER2 and centromere 17 (CEP17) ratio and the pCR to neoadjuvant therapy based on trastuzumab and pertuzumab.