[Lani]

unregistered--denosumab works differently than bisphosphonates like zoledronic acid,

Its mechanism of action may may it active in preventing all breast cancer metastases rather than just bone metastases and even breast cancer growth as well.

I think you give up too easily--try these two sentences, with my translations:
Two publications now provide evidence that progestin(progesterone family)-driven mouse mammary(breast) tumorigenesis(tumor formation) can be blocked by ablating(getting rid of) RANK signaling. Can the osteoporosis drug help breast cancer patients? The burning question now is whether the role of this pathway is conserved in the human breast(ie, the role is the same in human beings as in mice) and whether RANKL signaling has a role in the pathogenesis(process of causing) of one or more subtypes of breast cancer.