Come join others currently navigating treatment in our weekly Zoom Meetup! Register here: Tuesdays, 1pm ET.
Fill Out Your Profile to share more about you. Learn more...

Tumor marker vs Signatera ?


Metastatic BC. In hormonal treatment with Verzinio for 6 months. Signatera test came back negative and 0 yesterday and at the same time, CA2729 came back at 300. What could cause the specific test to show 0 Circulatiing tumor cells and the non specific test to show a fair amount of CTC?


  • moderators
    moderators Posts: 8,285

    Hi @mbrown2097,

    We would like to welcome you to, and see that you already have a good handle on how to use the discussion boards. One thing to note is that since many users do not have a medical background, they might not be able to answer this question, however they may be able to share a similar experience. 🙂

  • olma61
    olma61 Member Posts: 1,026
    edited July 2023

    To my knowledge these two tests look for different things. Signatera is the one that actually is supposed to detect circulating cancer cells, the tumor marker tests like CA 27.29 look for proteins in your blood that are commonly shed by cancer cells but can also be present for other reasons.

    That does seem to be a great disparity though, and something to definitely discuss with your onc.