Hormone-biological therapy in breast cancer: preclinical evidences, clinical studies and future directions

The development of resistance to endocrine agents is a major issue in the treatment of ER-positive breast cancers patients. The evidence of a cross-talk among signaling pathways and the recent advances in understanding biology of this neoplasm have led to the new concept of hormone-biological therapy.

Main aim of this review was to examine comprehensively concluded and ongoing clinical trials about endocrine agents combined with biological drugs. Second aim was to provide an up-to-date knowledge of preclinical studies in this flourishing field, considering several in vitro and in vivo models, by focusing on the main signaling pathways involved in breast tumorigenesis.

We performed a literature research for papers published in MEDLINE database until January 2009. We selected the most significant data presented as abstract or poster during the relevant international meetings for breast cancer (ASCO, ESMO and San Antonio Breast Cancer Symposium). Moreover, we systematically reviewed a public available registry of federally and privately supported clinical trials conducted in the United States and around the world to update information about conclusion of trials and ongoing trials not yet published.

Hormone-biological therapy is a relatively new option in the treatment of breast cancer and some combinations seem to be effective in certain settings. Numerous trials are ongoing and they will help to better clarify the role of different combined therapies. In parallel, cancer biology has a central role in a deeper understanding of this heterogeneous disease and preclinical studies will be necessary to test new compounds and strategies.