I am doing Signatera . I have had one blood draw (February )which showed no circulating blood tumor cells. My breast cancer was stage 1a. I was diagnosed in August 2021. My oncologist was willing to let me do Signatera . I have another blood draw in August . It is suggested to do blood draw every 6 months. I am not taking hormone therapy so I wanted to be proactive about my health and possible recurrence. You don’t have to be stage 4 to do these blood tests. Not all oncologist are willing to let their pts have this testing. If you do get a positive result it is then the question of what do you do next.