leaf?

I don't think its been tried for prevention of bc in those that have not had invasive bc. According to this citation, they are seeing if it can be used in high risk early stage invasive breast cancer to see if it prevents bone mets. http://www.ncbi.nlm.nih.gov/pubmed/17591815



Note it (as well as other biphosphonates) have been associated with jaw osteonecrosis http://www.ncbi.nlm.nih.gov/pubmed/17906299



In this study, the incidence of jaw osteonecrosis was less than 1%, but it was more common in breast cancer patients (still less than 2-3%). http://www.ncbi.nlm.nih.gov/pubmed/18435574