A class of osteoporosis prevention/treatment drugs called bisphosphonates have been associated in two studies with about a 30% reduction in invasive BC.
However, there needs to be more research to determine if this is just a correlation, or if these drugs actually lower the risk of breast cancer.
As japdip indicated, they work quite well for osteoporosis, but they also carry some risks that have led to an FDA warning, so it is important to weigh the risk-benefit ratio when deciding about using them.
I believe this drug is widely used in India but not in the U.S.
There are several drugs available in the U.S. for the treatment of Osteoporosis and all have some value. One with a similar name (Boniva) is used quite often and is said to have good results. Since we deal strictly with Breast Cancer issues on this Community you might look at the top of the page under "Health Information" where you will find a subtitle "Osteoporosis" and post there or read other posts and comments. Regards ....