For -2.7 a bisphosphonate is good! And it helps with preventing cancer, possibly. You can trust your docs. With -2.7 bone builders would not be covered anyway 🙂

If you cannot tolerate the Fosamax, then you can be considered to "fail" it and insurance might cover other meds. But talk to your doctor if you are experiencing such awful side effects. Some people do Prolia with cancer, but that can end up requiring a bisphosphonate when you stop! We are all between a rock and a hard place.

I could not do a bisphosphonate during my cancer treatment and lost a lot of bone. I was on an aromatase inhibitor like you, letrosole) for 5 years. Then Tymlos after the cancer meds, helped me catch up, though I fractured. If you can tolerate Fosamax it will protect you, perhaps on two counts- bones and cancer. Reclast is standard protocol, with my docs, but Fosamax is a good one if you didn't want to do that.