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!
Male 38; Australia
10/2018 Dx 3.5cm RC adenocarcinoma, 12cm from AV
Mod diff, EMVI+ LVI+. 4 liver mets
pT3N1aM1a; Stage IVa. MSS, NRAS (G13R)
CEA: Oct-18= 12; Nov-18= 14, Mar-19= 2.4, Aug-19 <2.0, Mar-20=2.2
11/18- FOLFOX x6
3/19- Liver resection
5/19- 25 x pelvic VMAT radiation; complete metabolic response
07/19- ULAR (robot), temp ileo, 1/27 LN
08/19- Missed a liver spot
08-11/19- FOLFOX x1, FOLFOXIRI x1, FOLFIRI x5
12/19- Liver resection #2
02/20- Ileostomy reversed
03/20- PET & MRI = NED!