Thyroglobulin

[jo1121057]

I had pappilary thyroid cancer 20 years ago, and assumed I was cured. Recently my throglobulin test came back a 6. It  has been unmeasureable right along.  My thyroid was completely removed and followed with radioactive iodine in 1992. I am concerened that the thyroid some how has returned. Is it possible that the test is wrong or can normal thyroid tissue grow back?


This discussion is related to Weight Loss - Is it Liothyronine?.

[abby51]

I also had my thyroid removed for Papillary cancer almost 20 years ago and had an undetectible TG up until about 3 years ago. I had several scans done including two PET scans and nothing ever appeared on the scans. I had two ultrasounds done. I had the scans done because once the TG went up it continued to gradually increase. It is still increased at this time, however, it has now started slowly going down. I did have the TG test repeated at a different hospital lab to be on the safe side and to be sure the test was accurate. I have never found a reason for why my TG started suddenly increasing.

[jo1121057]

Thank you for the info. I have not had the TGab tested. I will ask my endocrynologist about that test. I most likely will have the the TG re-tested.

[goolarra]

I'm not familiar enough to know if it's "common" or not to order an U/S, but it would seem appropriate as it would show regrowth if there is any.  

Have you ever had TGab (thyroglobulin antibodies) tested?  They can develop at any time, and, apparently, they make the TG test fairly useless.  Maybe you could repeat the TG and have TGab at the same time???  

[jo1121057]

Thank you also for the Link. I will check it out.

[jo1121057]

Thank your for your reply. I did have a test for Thyroglobulin 10 years ago that came back at a 4. The repeat test was less than 1. I think the lab made a mistake that time.
A neck ultrasound was ordered this time. Is that common?

[goolarra]

It is possible for thyroid tissue to regrow...we have at least one member who had that happen.

"If a person develops thyroglobulin antibodies, then the thyroglobulin test results may be falsely elevated or decreased, depending on the testing method used. Results must be interpreted with caution. The presence of the antibodies lessens or eliminates the usefulness of the thyroglobulin test as a tumor marker."

Here's the link if you want to read more:

http://labtestsonline.org/understanding/analytes/thyroglobulin/tab/test

Of course, it's always wise to repeat the test if there's any question of its validity.  Labs do make mistakes...