How hormones can cause breast cancer

Scientists at the Institute for Molecular Biotechnology at the Austrian Academy of Sciences (IMBA) clarified the association between the use of synthetic sex hormones and increased breast cancer risk. Their findings, published in the journal Nature, nourish the hope of preventive measures against hormone-dependent breast cancer. A new drug for osteoporosis could be the key.

Breast cancer is one of the most common cancers in Western societies. In Europe, one in eight women is affected in the course of their lives. Only a small proportion of the patients has inherited the predisposition, the tumor is usually acquired through external influences. Extensive long-term studies such as the "Million Women Study" (UK) and the "Women's Health Initiative" (United States) have shown the connection clearly.

An international team led by IMBA director Josef Penninger has now clarified the mechanism of how synthetic sex hormones can cause breast cancer in mice.

The DLD speaker is overwhelmed by the directness of the studies. "I'm really surprised of how massive the influence of RANKL-system on breast cancer is. Considering that millions of women take synthetic progestins, the results have an immense importance."

Now that we know the mechanism of the tumor development we can focus on preventive measures. Drugs that block RANKL could reduce the future breast cancer risk signigicantly.

The original research paper "Osteoclast differentiation factor RANKL controls development of progestin-driven mammary cancer" by Schramek et al. was published in Nature, 29.9.2010.