Hello...
I just read your message re: rising CEA levels during 5FU chemo treatments for rectal cancer...I had stage I or possibly II(a) rectal cancer...Had radiation, Chemo (5FU); then surgery; then more 5FU chemo therapy...My levels rose from a 2 to a 6 during the most recent chemo therapy--and unlike in your case--my chemo doctor says he is concerned and has ordered a PET scan...
Can you tell me what happened in your case? It is so similar to my situation...
Kathleen