[Estrogen receptor Beta isoforms -- functions and clinical relevance in breast cancer]

Abstract

Estrogen receptors (ER) are hormone regulated transcription factors which mediate the cellular estrogen response. So far two types of ER could be identified, ERalpha and ERbeta. ERalpha plays an important role as a predictive factor for the effectiveness of endocrine agents in the treatment of breast cancer. Patients with ERalpha positive tumors receive adjuvant endocrine therapy. Recent findings indicate a crucial role of ERbeta and its isoforms for the prognosis of breast cancer. This paper reviews the current knowledge on the functions of ERbeta and its splice variants.