"Ten years ago we formulated the hypothesis that RANKL might be involved in breast cancer and it took us a long time to develop systems to prove this idea", says Prof Josef Penninger. " I have to admit it completely surprised me just how massive the effects of the system were. Millions of women take progesterone derivatives in contraceptives and for hormonal replacement therapy. Since our results show that the RANKL system is an important molecular link between a synthetic sex hormone and breast tumors, one day women may be able to reduce their risk by taking blocking medicines in advance to prevent breast cancer".

A monoclonal antibody, denosumab, that blocks RANKL has been recently approved in the US and the EU for the treatment of osteoporosis, and is currently under review for the treatment of bone metastases in patients with advanced cancer. "Further studies will be needed to prove the principle of our findings", says Dr Daniel Schramek, who carried out the studies with Prof Josef Penninger at the Institute of Molecular Biotechnology in Vienna. "But we hope that medical trials using denosumab can be started in the near future to test whether the mouse studies can be directly translated to human breast cancer."

Source : Institute of Molecular Biotechnology of the Austrian Academy