Thyroid cancer

Thyroid cancer affects the thyroid gland, at the base of the neck. There are different types of thyroid cancer, but papillary thyroid cancer is the most common in younger people.

The thyroid gland

The thyroid gland is found at the base of the neck, just behind the hollow where the collar bones meet. The thyroid is separated into two halves, known as lobes. Usually a cancer is found in just one lobe, though it can occur in both.

Who does it affect?
What are the symptoms?
How is it diagnosed?
How is it treated?
What are the treatment side-effects?
After treatment

Who does it affect?

Thyroid cancer is a relatively rare condition, especially in younger people. It is more common in women than men.

What are the symptoms?

The first sign of thyroid cancer is usually a painless lump on the neck, which gradually gets bigger. Occasionally this lump may interfere with breathing or make it difficult to eat.

How is it diagnosed?

Thyroid cancer is usually diagnosed after an ultrasound scan and a needle biopsy. A needle biopsy involves the specialist inserting a thin needle into the lump and extracting a small amount of cells and fluid. These are inspected under a microscope to determine whether cancer is present.

How is it treated?

The treatment your child will receive for thyroid cancer will depend on its type, and how much it has grown or spread. The most common treatments for thyroid cancer are surgery and radiotherapy.


Your child may need surgery to remove the whole thyroid gland, or the part affected by the cancer.


The type of radiotherapy your child will receive depends on the type of thyroid cancer they have:

  • Radioactive iodine treatment involves drinking or taking a capsule of iodine 131 (also known as I-131), which then circulates through your child's body in their bloodstream killing the cancer cells. They will need to stay in hospital for a few days following this treatment.
  • External radiotherapy involves using high-energy rays to target the cancer cells. Your child will usually have a course of treatments at the radiotherapy department of the hospital over four to six weeks.

Talk to your specialist about your child's individual treatment plan.

What are the treatment side effects?

Your child will normally need to remain in hospital for 1–2 days after thyroid surgery so the specialist can ensure they have made a good recovery. If the nerve supplying their voice box is damaged during the operation, they may have a hoarse voice for a while. This normally goes away on its own.

Radiotherapy can also make your child feel tired and sick. They might experience skin irritation and hair loss in the area that is being treated by external radiotherapy.

After treatment

Hormone replacement

If your child's thyroid gland has been totally removed, they will need thyroid hormone replacement. This is necessary to keep your child's body functioning like it did before the cancer. They will need to take these thyroid-hormone replacement tablets every day.

Follow-up care

After treatment is complete, your child will still need to be seen regularly at an outpatients clinic for at least ten years. At this clinic, the specialist will be looking for any signs that your child's cancer has returned (this is known as a relapse). They will also check that their major organs, such as the heart and lungs, are still functioning correctly and haven’t been affected by the cancer treatment.

Long-term follow-up

Once your child's risk of relapse has reduced, ongoing follow-up will focus on looking out for potential long-term side effects of treatment. The risk of this depends on the type of cancer your child had and the treatment they received. A personalised surveillance plan is usually created that outlines the specific long-term follow-up and ongoing investigations that your child requires.

Many people are at low risk of future health problems but some will have significant ongoing health needs. Talk to your specialist about the potential long-term side effects of your child's treatment.

Where next?

Updated November 2017, next review due 2019.