Our experience was that multiple formulas in useful amounts of potent choices were necessary to re-light chemo activity.
A little bit like peeling an onion to hit multiple pathways, avoid duds and interferences.
Most people do total guesswork, and hence usually have less effect.
How would you choose between 400 mg of curcumin and 13,000 mg? (Some MGUS patients can actually use 6 - 13 grams to stop their markers)
We built up history and improvements, then could swing multiple changes monitored with many parameters in fairly stable conditions.
But the most important is having some evidence of chemo turned "on", avoiding side effects, and not making continued mistakes.
Some improvements can be odd ball chemistry hits that exploit tissue defects. (e.g. a 6mm lung pellet turned to stone in a chemo-near calcium overload environment)
The literature shows continuous chemistry sometimes breaks resistance that heavier chemo cycles already failed.
We can't just randomly copy others working formula and expect it to instantly work, even if there is a lot of overlap.
Although I didn't see an actual CA199, your comment implied a much different CA199/CEA ratio, a somewhat different biology at work.
It's always best to just report at least one quantitative number rather than opinions on panels not part of their CRC education - a particular doctor is usually not specialized enough.
My wife's experience may reflect less grams of residual tumor load and adverse mutation from your chemo cycles but we did develop much of it with the PALN "mega"cluster in place during year 1 and activated after the 5FU dip for folic acid toxicity.
It's best to work things out with the blood tests - to see when chemo activity turns "on" and "off", what else improves, what doesn't, or even what deteriorates (e.g. liver functions, CBC fractions) for bad choices or trial failures.
The most useful bloodwork parameters varies somewhat between patients e.g. CA199 or LDH might be critically important to some vs biologically constant/absent and almost useless after 1-2 measurements.
My wife's spreadsheet tracked 25+ useful panels and markers for real time trials and corrections, so we could create useful changes pretty fast.
For you, if you tried to make an instant history on the biweekly and monthly bloodwork, some basics to list might be: date, CEA, MCV, ALP, rdw, WBC, RBC, platelets, Hgb, GGT (GGTP), 1-2 inflammation markers (e.g. ESR, hsCRP).
A fairly full liver suite baseline would be AST, ALT, ALP, GGT, LDH, bilirubin, PT/INR, AFP
Lest you think this is wildly burdensome, it was an incremental 15 minutes to review and plan after each new blood test vs 2 - 5 minute oncology with "standard" once we got it working. The effort is in development of the information and support base i.e. if std drs did my/their homework.
MCV, ALP, rdw, Hgb, WBC, RBC, platelets are all in the most basic CBC report with differentials. GGT is a less common liver function but should be monitored for HAI purposes.
watchful, active researcher and caregiver for stage IVb/c CC. surgeries 4/10 sigmoid etc & 5/11 para-aortic LN cluster; 8 yrs immuno-Chemo for mCRC; now no chemo
most of 2010 Life Extension recommendations and possibilities + more, some (much) higher, peaking ~2011-12, taper chemo to almost nothing mid 2018, IV C-->2021. Now supplements