The Colon Club

Hi,

Most of the research I’ve seen into the reason for a rise in CEA levels during chemo is for metastatic colon cancer with the explanation provided for this ‘chemo flare’ being put down to secretion of CEA from dying cancer cells. Not seen much research though into a rise in stage III patients where you wouldn’t expect there to be many remaining cancer cells and thus don’t think you’d expect a material change in CEA due to these being killed off? Hence just wondering if anyone has come across the theory to explain this (i.e. assuming no non chemo related reasons such as inflammation, infection etc) - have seen some mention of inflammatory reaction to oxaliplatin but not sure you’d necessarily expect this to result in a steady rise during chemo especially when bloods are taken about 19 days after each infusion.

My CEA was 1.9 when CAPOX started in December (no reading pre surgery) then 3.2, 3.5 and finally 4.6 after final cycle end Feb. Have my next test later this week with CT scan the week after (both brought forward from original plan of Sept because of the CEA rise and the BRAF V600E mutation putting me more at risk of earlier recurrence). Already had a CT done in Feb during final cycle which was NED and recent colonoscopy clean too.

Thanks.

I had the rise as well. Also started in December and it rose through six or seven months of chemo. The oncologist ordered a CT and it was clear. In my case, it was most likely due to working out as my workouts increased as my chemo progressed.

We were told that certain chemotherapy agents can cause it to rise in its own .
Stu

Static500 wrote:... Not seen much research though into a rise in stage III patients where you wouldn’t expect there to be many remaining cancer cells and thus don’t think you’d expect a material change in CEA due to these being killed off?

Hence just wondering if anyone has come across the theory to explain this...

Yes, I have come across such a theory, but it would require expertise in organic chemistry to properly understand it and to explain the process. Basically, the issue is this (in my opinion):

1. Your CAPOX chemo is based on capecitabine which is a pro-drug that is metabolized in the liver. Other types of chemo (i.e., IV-based chemo) do not have this characteristic. There are several references in the literature that mention this issue: It is the metabolism cycle in the liver that sets capecitabine apart from all of the IV-administered chemo drugs.

2. CEA is a glycoprotein, and it is also metabolized in the liver.

"...The liver appears to be essential for the metabolism and/or excretion of CEA..."
Reference: https://pubmed.ncbi.nlm.nih.gov/361200

3. It is probably the case that the concentration of chemo in the blood increases over time with each round administered. The longer you are on chemo, the greater the cumulative effect. Once you stop chemo the concentration then gradually diminishes over time and presumably CEA will gradually decrease over time, too.

What all of this probably means is that if you are taking the pro-drug capecitabine over a period of weeks or months, your CEA will probably increase over time. This is to be expected. It is normal. This is likely due to the increased involvement of the liver in the metabolism of the drug. This rise over time may not happen with IV-administered chemo regimens like FOLFOX because in that case the 5-FU drug is delivered directly into the blood stream without the need to first transit through the liver.

This is just my layman's view of what is going on. Others may disagree.

Thanks all for the insights.

NHMike - interesting view fe the workouts. I was doing a heavy exercise schedule all through chemo of running twice a day c100miles per week but something my body is very used to so not sure to what extent that might have contributed.

I’m stage III and my CEA rose during chemo. I asked my oncologist and she said that I should not even be having CEA tested during Chemo because that causes it to rise. She had the nurses remove the order for it from my lab requests.

It isn’t a good marker for me, but we have been checking it post Chemo again and it hasn’t gone back up.

I had my CEA, along with other bloods, tested prior to each chemo treatment (every two weeks). It bounced around a little but didn’t trend upward. I can fully understand your anxiety as my CEA results have certainly given me a lot of anxiety over the years. It was normal for me to bounce around and go up a little. Mine would go up a little like yours then would drop again for the next one. I think it’s a good idea to have it tested again soon. I had a CT six months after my chemo finished, then yearly. Best wishes. Try not to worry

Latest result now in at 2.6 so nice decline from the Feb 4.6 figure and so previous upwards trend looks likely to have been chemo related I guess.