You might ask your oncologist whether Anastrozole- estrogen blocker - could substitute for chemo. Anastrozole has a bad reputation on this forum! Not without reason. But it's hard to separate cause and effect. For example, I get mild leg pain at night. Is that due to Anastrozole or neuropathy? Or just the effects of ageing, at nearly 77? Everyone over 40 has some arthritis. And you CAN counter the effects of Anastrozole on your bones with high intensity supervised weight lifting etc. As I have done after only six months.
See the discussion of the Onero program - developed here in Brisbane - on the Osteoporosis forum. Not much awareness yet in the US and Canada, apparently.