How do you know if its progressing?

I too had no inkling the cancer had come back. Was also having regular treatment by my physio for a sore back which always seemed to resolve after a couple of treatments. It was only a casual comment to my surgeon that he decided I should have a CT and bone scan which picked up the mets in my spine. MBC had never entered my mind. I was started on Ribo and denosumab. Unfortunately they have not worked for me after 5 months as shown by my latest CT scan and so I will be starting oral chemo. It was shattering news but since joining this forum and reading other comments I am feeling in a better place.. There is so care and much support among everyone.