Your doctor may also refer you for blood tests such as:
Complete blood count (CBC) measures the number of red, white, and other blood cells to ensure proper bone marrow function. It also gauges whether treatment is affecting blood cell counts.
Serum chemistry test evaluates levels of electrolytes, such as calcium and potassium, and certain enzymes (proteins). Doing so shows how well various organs are functioning. Abnormal levels of these substances can mean that cancer has spread.
Thyroid-stimulating hormone (TSH) tests check for the overall activity of the thyroid gland. Levels of TSH may be too high if the thyroid is not producing enough hormone. TSH is usually normal when cancer is present in the thyroid.
T3 and T4 (thyroid hormones) are the main hormones made by the thyroid gland. Tests measure the levels of these hormones to offer insight about thyroid gland function. The T3 and T4 levels are usually normal in thyroid cancer.
Thyroglobulin and thyroglobulin antibody
Thyroglobulin is a protein made by the thyroid gland. A common way to treat thyroid cancer is to remove most of the thyroid gland with surgery and then use radioactive iodine to destroy any remaining thyroid cells. If certain levels of thyroglobulin remain in the blood stream after treatment, it could be a sign that the cancer could be coming back.
Calcitonin is a hormone that helps regulate the body’s use of calcium. It is made by certain cells in the thyroid gland that can develop into medullary thyroid cancer (MTC). This test may help diagnose MTC or identify a possible recurrence after treatment.
Carcinoembryonic antigen: People with MTC often have high levels of carcinoembryonic antigen (CEA) in their blood streams. This test may help diagnose MTC or identify a possible recurrence after treatment.