Advances in adjuvant therapy for breast cancer

The development of adjuvant theraphy has made a significant positive impact of clinical outcomes for patients with cancer. Over the past 30 years the field of adjuvant theraphy has envolved from its cyclophosphamide/methotrexate/5-flourouracil beginnings by adding new agents and modifying treatment schedules and dosing. More recently, the application of targeted therapies based on hormone receptor status and HER2 expression is providing a new level of efficacy for these patients. The biologic agents tratuzumab, a monoctonal antibody directed against HER2, first demonstrated significant activity in patients with metastatic breast cancer, reducing the risk of death by 30%. The agentwas then evaluated in an adjuvant setting in several large trials. in a recently published joint efficacy analysis, the addition of tratuzumab to standard adjuvant chemotherapy regimens led to a 52% reduction in events (ie, recurrent cancer, second primary cancer, or death before recurrence) and significant improvement in overall survival. These dramatic findings highlight the need for accurate HER2 testing to best identify the HER2(+) patients who would benifit from the treatment. Currently there is some debate about how to best approach HER2 testing: with the protein-based immunohistochemistry or the genetic-based flourescence in situ hybridization. Current research evaluating the different techniques may help to settle dis question. Finally, new targeted agents are being investigated and ongoing research aims to identify additional potential therapeutic targets to further improve outcomes from these patients.