The adjuvant treatment of breast cancer has become standard of care a spectrum of biologic and prognostic factors are considered before a therapeutic strategy is implemented in this text leading investigators in the field discuss current management and critical investigative issues steven t rosen md. The introduction of adjuvant endocrine therapy ovarian ablation and adjuvant chemotherapy in the 1960s was a paradigm changing event based on improved understanding of the natural history of human breast cancer and the increased realization that micrometastases were in existence in most patients at the time of initial diagnosis 1 2 the initial steps were timid and the first few clinical trials were substantially underpowered to answer with any degree of certainty whether . What is adjuvant therapy adjuvant therapy is treatment given in addition to your breast surgery its used to kill any cancer cells that may be left in your breast or the rest of your body its also sometimes given before surgery to help make the procedure easier to do adjuvant therapy lowers the chance of having your breast cancer come back. Introduction breast cancer survivors have a two to six times greater risk of developing a second primary contralateral breast cancer than women in the general population have of developing a first breast cancer 1numerous randomized trials of adjuvant tamoxifen therapy have documented substantial reductions in the risk of three clinically important breast cancer outcomes specifically . Trastuzumab which is an anti her2 molecular target therapy in combination with adjuvant chemotherapy is recommended for patients with her2 positive cancer and those with breast tumors larger than 1 cm trastuzumab should not be used simultaneously with ac because heart failure is an adverse event associated with both drugs