Bone ostereporosis

Hi everyone. I have been on a targeted therapy for secondaries in the chest for two years with Letrozole and calcium high dose. It became ineffective in June and I am now taking another targeted therapy with Fulvestrant injections. I have now developed a arthritic right sided neck. He has suggested a subcutaneous injection to start next month. My question is should I have been having the injection two years ago???

janeruby