I was stable in the 30's for years. Mine jumped to 60 then 80's when my body stopped reacting positively to my meds (Ibrance and Faslodex at the time.) It was just one of several markers I had. I was extremely fatigued, suspected a tumor growing near my sternum and saw a growth on my clavicle. So, it was just one of many things. On it's own, it would just likely make me less likely to ignore something I might have otherwise. The CA27-29 is also tricky because some women have numbers in the hundreds! I'd take something to help me sleep and be grateful research has given us more than 1 tool to use. Best of luck to you!