My CEA was 5.8 when they checked it in November but all scans were clear other than some thyroid nodules. I had an ultra sound before Christmas and they found 2 nodules and a cyst in one side of my thyroid. Hashimoto's has been mentioned. I'll see a thyroid specialist/ surgeon this coming week.
If you have a rising CEA and scans are clear, ask for thyroid screenings. You can search and find dozens of articles (medical papers) proving even an underactive thyroid can cause an elevated CEA.
I'll let you know what doctor says but I'm expecting surgery due to the symptoms like choking on food, sensation of lump in throat, especially when I lie down at night, hoarseness.
Today is my 67th birthday. I was dx'd with Stage IIIB nine years ago and had surgery Jan. 7th.