Question: This is about CEA. I finished chemotherapy 6 months ago for breast cancer. Double mastectomy, node negative, 2.3 cm iDC, no lymphovascular invasion. Had first PET one year ago a week before surgery and was OK. CEA preop was only (.7) and ca 15.3 was 5.6. During chemo my readings were 1.3, 1.1, 1.0 and 6 weeks post chemo went to 2.7, 3.7,3.6, 5.4 ,3.9 , 4.7, 6.0 then 5.4 again(last week). My very low read of .7 was with the tumor inside!!. I had a second PET XXXXXXX 29 and was OK(one month after it began to rise and 2 weeks after began tamoxifen), PET sowed inflammation still present along mastectomy scars. Also found thyroiditis and (subclinical hypothyroidism) high TSH (10). i began synthroyd. Read that hypothyroidism may cause elevated CEA. I read 2.5 is for non smokers and 5 for smokers, I do not smoke. My lab has upper limit of 5. my onc said values are arbitrary my point is that if when the tumor was in it was so low, then it probably did not release this glycoprotein!.My ca 15.3 was 8.7 last time and UNL is 31 so this one is very low.My onc said it was Tamoxifen(she is certain about in her experience) and inflammation still along scars however, I had that inflammation before(mastectomy 8 months earlier) and CEA was low. it started to go up right after i began taking Tamoxifen. Im concern with mets despite good PET Do you agree my tumor did not release CEA or it would have been higher when inside me? do you agree with my onc about Tamoxifen behind this? . I found only one article where it mentioned "hormonal therapy for breast cancer may actually raise CEA" and/or hypothyroid reducing hepatic clearance of CEA thanks

by the way,yesterday I had a FOB (fecal occult blood) test at the gynecologist and it was fine

the question above is an update because of the tamoxifen an thyroid issue. thanks