According to a report in The Lancet (July 23rd 2015) Bisphonates (which are used to strengthen bones), if administered early to breast cancer patients before the cancer has spread to the bones, can limit metastases.
Analysing data from 18,766 women, the reduction in metastases to the bones, shown by women taking bisphonates overall was significant. While there was little advantage in pre-menopausal women, post-menopausal women had ‘highly significant reductions’ in recurrence, bone occurrence and breast cancer mortality.
Ref: The Lancet; October 3rd 2015, Vol 386