TGF-β1 could be a missing link in the interplay between ER and HER-2 in breast cancer

Breast cancer is a very heterogeneous disease considering a number of biomarkers which are under investigation. However, most important biomarkers in a clinical setting are ER (estrogen receptors) and HER-2 (human epidermal growth factor receptor 2), but still only as predictive markers for tamoxifen and trastuzumab therapy. Their prognostic role is still subject of investigation. On the other hand, although, TGF-β1 is known as marker of invasiveness and metastatic capacity of breast cancer cells, this marker has never been considered to be introduced in routine clinical setting. TGF-β1 is ER regulated biomarker which act synergistically with HER-2. Aim of this study is to show that clinical significance of determination ER and HER-2 status could be improved, when they are related with TGF-β1 as additional biomarker. It seems that TGF-β1 could make a difference regarding prognosis and prediction in breast cancer patients. This hypothesis could be easily verified in corresponding clinical research.