CEA levels: I need some reassurance
My mother was diagnosed with triple-negative breast cancer on January 20 of this year. Her CEA level was normal (2.6; her hospital has a normal range between 0.0 and 3.8). She had a complete mastectomy on March 3 and started 4 rounds of TC chemo on March 30. She was T1CN0 with no lymph node involvement. On March 16, her CEA went to 3.9.
Each round of chemo was followed by an administration of Neulasta and her last chemo was on June 1. She was completely fine during chemo and has regained a healthy appetite and better sleeping patterns after all of this. However, I am concerned that after six weeks out of chemo, her CEA was retested and was 4.2. I wasn't terribly worried because I thought that it was a transient thing due to chemo and the Neulasta. However, this week she was retested and now the CEA is 5.6! Her other tumor marker, CA 27-29 have been in the normal range. Her CBC are looking great but her LDH has gone slightly over the normal threshold (262). I need some comfort or something that tells me this rise in CEA isn't due to Mets or a secondary cancer elsewhere. Her doctor doesn't want to see us until November but that just seems too far off. She wants her to have a colonoscopy. Forgive me for my ramblings but I think I shall go mad if I don't get some sort of guidance. I've scoured the internet but there really isn't anything that points to rises in CEA nearly three months of chemo cessation that doesn't have to deal with cancer. Please help!