Hi Lisa. I've found the 27-29 not to be very reliable as mine, having started at 88 back in 2019, blipped down and up over the course of the last 3 years,never going above the original number but never below 43. I'm tested monthly. It's only recently one of my meds was changed due to a slight bit of progression and my markers are up to 92 which can be sign of cancer "die off". I've been reminded that sometimes tumor markers "can be" somewhat telling but scans are what truly tell the story. You can have markers rise but no progression. I also know a lady whose numbers are in the teens but has mets all over her body and is stable. I always go by how I feel. Do I hurt anywhere? If I do, my Onc may scan to see if something new is going on. Even then I've had scans show no progression.
My feelings are that I could do without this particular marker test but my Onc insists in case the numbers ever take a huge jump, like into the hundreds.
Peggie