There are several different types of thyroid cancer, the most common is papillary thyroid cancer, which usually grows in one lobe of the thyroid gland (about 70-80% of all cases). Follicular thyroid cancer accounts for about 20% of thyroid cancers.
Less common thyroid cancers include medullary thyroid cancer, anaplastic thyroid cancer and thyroid sarcoma or lymphoma.
In 2013, 2553 Australians were diagnosed with thyroid cancer, and it is more common in women.
Of all cancers, thyroid cancer has the highest five-year survival rate at 96%. The prognosis for women is slightly higher at 97%.
In 2014, there were 133 deaths caused by thyroid cancer in Australia.
There are often no obvious signs of thyroid cancer, however you may have one or more of the following symptoms:
- a lump in the neck or throat that may get bigger over time
- difficulty breathing or swallowing
- swollen lymph glands in the neck
- a hoarse voice.
You should talk to your GP if you have any of these symptoms, as often thyroid cancer develops slowly, without obvious signs or symptoms.
Some factors that can increase your risk of thyroid cancer include:
- a family history of the faulty gene called RET gene
- having a thyroid condition such as an enlarged thyroid (goitre) or thyroid nodules
- exposure to some forms of radiation, such as childhood radiotherapy treatment.
Diagnosis for thyroid cancer
Tests to diagnose thyroid cancer may include:
A blood test will check the levels of hormones (including T3 and T4) and the thyroid-stimulating hormone (TSH). A blood test can also help to identify non-cancerous thyroid conditions, such as hypothyroidism (underactive thyroid) or hyperthyroidism (overactive thyroid).
A painless scan that takes about 20 minutes, an ultrasound produces pictures of internal organs. It can assist in determining if any lump in your neck is solid or fluid filled. It will also show whether any lymph nodes have been affected.
A doctor removes some of the thyroid tissue for examination under a microscope. The most common type of biopsy is called a fine needed aspiration, alternatively a doctor may do a hemi-thyroidectomy to remove tissue sample.
This test is usually done if blood tests indicate an overactive thyroid (hyperthyroidism). A small amount of radioactive liquid (such as iodine) is injected into a vein in your arm prior to a gamma camera scan being done. The amount of radioactive liquid taken up by the thyroid gland is then measured.
If cancer is detected in your thyroid, you may have other scans to see if the cancer has spread to other parts of your body, such as a CT, MRI or PET scan.
Most people with thyroid cancer receive a combination of treatments from surgery, thyroid hormone replacement therapy, radioactive iodine treatment, radiotherapy or chemotherapy. This will depend on the type and stage of thyroid cancer you have.
The most common form of treatment is surgery, whereby a section or the whole thyroid gland is removed (partial or total thyroidectomy). As a preventative measure, the surgeon may also remove nearby lymph nodes (called a neck dissection).
Thyroid hormone replacement therapy is given as a daily tablet to replace the thyroid hormones (thyroxine or T4) that your body can no longer produce after surgery. If you have had thyroid surgery you will need Thyroxine replacement for the rest of your life as it is very important to keep your body functioning at a normal healthy rate.
Radioactive iodine treatment
A form of internal radiotherapy, Radioactive iodine treatment is typically taken in a gel tablet form. It destroys any cancer cells left behind after surgery. Talk to your doctor about the safety measures required for this type of treatment.
External radiotherapy (the use of high energy X-rays) may be given after surgery, particularly if the cancer has spread to lymph nodes in the neck, or for thyroid cancers that are less responsive to radioactive iodine treatment (such as medullary or anaplastic thyroid cancers).
Chemotherapy is sometimes used to treat thyroid cancer that is not responding to radioactive iodine treatment. It is usually given as a drug that is injected into a vein (intravenously).
Depending on your treatment, your treatment team may consist of a number of different health professionals, such as:
- a GP who will arrange initial tests and look after your general health
- an endocrinologist, who specialises in diagnosing and treating disorders of the endocrine system
- an endocrine surgeon, an ENT surgeon, who treats the ears, nose and throat, or a head and neck surgeon
- a nuclear medicine specialist
- a cancer nurse
- other allied health professionals, such as dieticians and physiotherapists.
In some cases of thyroid cancer, your medical team may talk to you about palliative care. Palliative care aims to improve your quality of life by alleviating symptoms of cancer.
As well as slowing the spread of thyroid cancer, palliative treatment can relieve pain and help manage other symptoms. Treatment may include radiotherapy, chemotherapy or other drug therapies.
There is currently no screening for thyroid cancer available in Australia.
It is not possible for a doctor to predict the exact course of a disease, as it will depend on each person’s individual circumstances. However, your doctor may give you a prognosis, the likely outcome of the disease, based on the type of thyroid cancer you have, the test results, the rate of tumour growth, as well as your age, fitness and medical history.
The most common types of thyroid cancer have very good long-term prognosis, especially if the cancer is found early.
There are no proven measures to prevent thyroid cancer.
However, if familial medullary thyroid cancer is detected in a family, the rest of the family can be tested for the mutated gene. If a family member has the mutated gene, they can elect to have preventative treatment, such as surgery to remove the thyroid.
Understanding Thyroid Cancer, Cancer Council Australia ©2016. Last medical review of source booklet: January 2016.
Australian Institute of Health and Welfare (AIHW) 2017. Cancer in Australia 2017. Cancer series no. 101. Cat. no. CAN 100. Canberra: AIHW.
Australian Institute of Health and Welfare (AIHW). Australian Cancer Incidence and Mortality (ACIM) books: Thyroid cancer. Canberra: AIHW.