Firstly, yes - usually by 1-2 points for me when it was elevated. Different labs, plus things like inflammation, exercise/injury, and smoking can affect it.
Secondly, there are at least 2 different test methods in common use - Roche and Bayer-Siemens. These can give slightly different results with different reference ranges.
Finally, as others have said - there are all very low results. My lab doesn’t even report below 2 (just “<2”) as it’s not clinically relevant usually, and I’m not sure how accurate the decimal is that low.
Anyway, looks like all good news to me!
10/2018 Dx RC, 12cm high
Mod diff, EMVI+ LVI+. 4 liver mets
pT3N1aM1a Stage IVa. MSS NRAS G13R
CEA: Nov-18= 14, Mar-19= 2.4, Aug-19 <2.0, Mar-20=2.2, May-20=1.9, Jun-20=2.1, Sep-20: 2.1, Dec-20: 2.3, Mar-21=2.5
11/18 FOLFOX x6
3/19 Liver resection
5/19 25x pelvic radiation; complete met. response
07/19 ULAR w ileo, 1/27 LN+
08/19 Found liver spot
08/19 FOLFOX x1, FOLFOXIRI x1, FOLFIRI x5
12/19 Liver resection
02/20 Ileo reversed
03/20 NED (CT/PET/MRI/scope) - latest scans Mar ‘21