Trastuzumab Administered Concurrently or Sequentially to Anthracycline-containing Adjuvant Regimen for Breast Cancer

Most of the published data support the preferential use of an anthracycline-containing adjuvant regimen for individuals with HER2-positive tumors. Concurrent anthracyclines and trastuzumab, however, are contraindicated due to the observation of unacceptably high rates of cardiotoxicity in a large randomized trial in the metastatic setting. However, in neoadjuvant setting, trastuzumab concurrently with an anthracycline-containing chemotherapy regimen had shown high pathological complete response (pCR) and very low cardiotoxicity. All large adjuvant trials have evaluated only the sequential strategy of administering anthracyclines and trastuzumab. The safety and efficacy of trastuzumab concurrently with an anthracycline-containing chemotherapy regimen has never been evaluated in adjuvant setting. Given the similar patients characteristics, the investigators hypothesize that trastuzumab concurrently with an anthracycline-containing chemotherapy regimen would not increase cardiotoxicity but efficacy.