Cancer was detected after I had a TT My Thyoglobulin levels had been non detectable They are now at 0.5. Could that mean cancer is returning? Thx

Thyroid cancer. The presence of thyroglobulin means there is some kind of thyroid tissue, normal or cancer. There are many questions that you should address with your Endocrinologist: was this Tg measured while on synthroid (thyroxine)? adequate dose? Did you have RAI following surgery? Total body scan? When was last ultrasound? CT of neck? How big was the initial cancer? But overall, don't worry. This can be dealt with.