[Potential risk and benefit of the combination of trastuzumab to chemotherapy and radiation therapy in non-metastatic breast cancer].

Trastuzumab (Herceptin) is the first humanised monoclonal antibody targeting the HER2 antigen in breast cancer. HER2 receptor has been individualised 20 years ago. During the past 10 years, trastuzumab administration has radically modified the prognosis of the patients that are treated for HER2 positive breast cancer. Its efficacy has been demonstrated in the metastatic and adjuvant settings. While, trastuzumab based-regimens became the standard of care in the treatment of HER2/neu positive breast cancer, the optimal combination (concurrently or sequentially) to chemotherapy and radiation therapy is still unknown. Indeed, while the concurrent administration of trastuzumab and anthracyclines is not recommended because of a high risk of cardiac toxicity, there is no published data on the best sequence of trastuzumab and radiation therapy administration, particularly when internal mammary chain is involved. The benefit/risk ratio of the concurrent and sequential administration of trastuzumab with chemotherapy and radiation therapy will be discussed in this review.