I never had it to my knowledge, and not too familiar with it, but It's used to test for autoimmune diseases. A healthy person can test positive, so It's not used for diagnosis, just rule out certain diseases, but then other specific tests can be done based on findings.

I heard of SCCA, Squamous Cell Carcinoma Antigen test being done to monitor for SCC recurrencent or persistent disease. but should not be solely relied on either.

My oncologist ordered a CEA test, carcineombryonic Anigen, for my next visit, maybe due to my anemia, and is mostlu used for other type of cancers especially colon, rectal, but also pancreas, breast, ovary, lung, but myndoctor mentioned before, she that she thought my CEA level would have gone down after surgery for my neck?