Bone metastasis is the only type of metastasis that can be controlled, but not cured, by drugs. Treatment is only given once the metastasis has been identified, which is normally too late. Preliminary studies indicate that the same drugs used to treat metastasis could also be used to prevent it, and identifying those patients at risk of developing bone metastasis is therefore very important.

Now, researchers from an International consortium led by the Institute for Research in Biomedicine have identified the gene responsible for metastasis of breast cancer to the bone.  The team state that their new study may be key to the early detection of patients at risk of developing metastasis to the bone and that this new knowledge may accelerate the development of the first preventive treatment of bone metastasis.  The opensource study is published in the Journal of National Cancer Institute (JNCI).

Previous studies show that about one million new cases of breast cancer are diagnosed each year. Preventive treatment for bone metastasis can have unwanted side effects and comes at a high cost, making a broad administration of the drugs an unviable option, even less so considering only 15-20% of patients are likely to develop metastasis over time.  In order to implement a well-designed clinical trial, the medical team first need to know which patients may benefit and which ones will not.  The findings of the current study can distinguish these patients in a way that wasn’t possible before.

The current study analyzed more than 900 clinical samples of primary breast tumours.  The group focussed on the analysis of estrogen-receptor-positive breast tumours since they specifically tend to metastasize to the bone, and represent 80% of all breast cancers. The results indicate that the gene MAF triggers a set of functions in the cell that allow metastasis to take place.

Data findings show that in tumours in which the MAF gene is altered, the risk of metastasis to the bone is 14 times higher than in those in which it is unaltered.  The researchers conclude that as this gene reliably predicts metastasis to the bone, studying whether it is highly expressed in breast cancer patients to determine whether this also happens in a clinical setting is an important next step.

The team surmise that it could improve the quality of life of these patients and the way clinicians manage their cancer.  For the future, this discovery has been patented and transferred to Inbiomotion, a spin off from the IRB Barcelona and ICREA, founded at the end of 2010. Inbiomotion has now delivered the technology and has begun to validate the marker in clinical trials in 3,300 patients.

Source:  Institute for Research in Biomedicine (IRB Barcelona).