Thyroid hormone replacement after surgery for thyroid cancer
The usual long-term thyroid hormone replacement drug is thyroxine (T4), and this is normally started after radioactive iodine treatment. Most people only need to take thyroxine once a day.
Some people with very small papillary or follicular thyroid cancers will only have surgery and no radioactive iodine treatment. They will be started on thyroid hormone replacement straight after surgery.
The thyroid hormone tablets have two functions:
They reduce the risk of the cancer coming back if you’ve had papillary or follicular thyroid cancer.
They keep the body functioning at its normal rate.
Thyroxine as a treatment for papillary or follicular
Thyroxine is an important treatment in reducing the risk of thyroid cancer coming back after surgery. It is used to stop the body from making thyroid-stimulating hormone (TSH).
TSH stimulates the thyroid to produce thyroid hormones. But in people who’ve had papillary or follicular thyroid cancer, it can also encourage thyroid cancer cells to grow.
Thyroxine levels may be kept slightly higher than normal for people who have thyroid cancers that are more likely to come back (high-risk cancer). The level may be kept just below normal for people with low-risk cancers.
Keeping the body’s normal rate of functioning
Without hormone tablets you would develop the signs and symptoms of hypothyroidism, such as weight gain, tiredness, dry skin and hair, and physical and mental slowness. You may not need to start taking hormone tablets straight after surgery; your doctor will tell you when to start.
Following the operation, if you’re likely to need radioactive iodine treatment, you may be given the hormone tablet liothyronine sodium (T3, Triiodothyronine or Tertroxin®). This is given until you have finished treatment.
You’ll be carefully monitored in a specialist clinic to make sure that you’re having the correct dose of thyroid hormone replacement. Regular blood tests will be needed to check the levels of thyroid hormones in your blood. It can sometimes take many months to find the right dose of thyroid hormones for you. You may have a variety of symptoms, such as tiredness, during this time. Once the correct dose is found, there should be no side effects from taking these tablets, as they are simply replacing the hormones that the thyroid gland produces naturally.
It’s important to remember to take the thyroid hormone tablets every day. It can help to take them at the same time daily to ensure you get into a routine. It’s also important to check with your pharmacist that the type of thyroid hormone tablets you’ve been given are exactly as prescribed.