Unfortunately, I had stage 3b colon cancer diagnosed a little over a year ago. I'm due for a 3 month check-up (bloodwork, etc) in mid June but I'm postponing for a few weeks as I'm traveling overseas to visit with family and don't want to deal with any possible CEA issues before I leave. My annual CT scan is due in mid-September.
By the way, my oncologist told me he would. not proceed with another scan (presumably a PET scan) immediately after an increased CEA. He would repeat the blood test before moving forward with additional testing.
Best wishes to you and good luck with the rest of your chemo.