What is thyroid cancer?
Thyroid cancer is a rare type of cancer that affects the thyroid gland, which is a small gland in the front of the neck. There are several types of thyroid cancer but the good news is most can be cured and they’re usually very treatable.
Thyroid cancer is more common in women than men. It can occur at any age, but two thirds of all cases are found in people between the ages of 20 and 55. Women in both the UK and the US tend to get thyroid cancer most often in their 40s and 50s. In many cases, thyroid cancer can be cured completely.
Here’s an overview of the key thyroid cancer symptoms, who is most at risk of developing it, and what your doctor – and your support network – can do to help.
About your thyroid
Your thyroid is a gland and its job is to make thyroid hormones. These help your body stay warm and keep all of your organs working normally.
A small, butterfly-shaped gland, your thyroid sits behind the hollow where your collar bones meet, just in front of your windpipe (trachea). You can’t usually feel your thyroid gland.
Signs and symptoms of thyroid cancer
Thyroid cancer develops slowly and, for this reason, it often doesn’t cause any symptoms. Here are the signs to look for:
- a lump in the front of your neck – but around 19 out of 20 thyroid lumps are not cancer, so only 1 out of every 20 is likely to be
- the lump feels firm, gets bigger over time and doesn’t move around under the skin when you touch it
- your thyroid gland is made up of two halves, called lobes, which are joined together by a thinner bridge of tissue called the isthmus. Thyroid cancer is usually found in just one lobe, so you may only feel a lump on one side of the space between your collar bones
- it can sometimes be found in both thyroid lobes
Occasionally, if it’s large enough to press on your windpipe (oesophagus), thyroid cancer can cause one or more of these symptoms:
- pain in your neck, ear or jaw
- difficulty in swallowing or breathing
- a feeling like a ‘tickle in your throat’
- a hoarse voice or a change in your voice
- swollen glands in your neck
Although it happens rarely, some thyroid cancers can also make the hormone calcitonin, which causes:
- flushing of your face
What is a neck lump more likely to be?
Most lumps in the thyroid gland aren’t cancer (around 95% of neck lumps are something else). They are more likely to be things like thyroid nodules, an infection or a goitre, but just to be sure you should always see your doctor as soon as possible if you notice a lump or have any of the other symptoms listed above.
If you’re not sure whether to see a doctor, use our Smart Symptom Checker to help you work out if an appointment is your best next step.
Who is more at risk of thyroid cancer?
We don’t know exactly what causes most thyroid cancers, but there are some factors that might increase your risk of developing it. Remember, having any of these risk factors doesn’t mean you’ll develop thyroid cancer.
Risk factors include:
- age – the highest number of women diagnosed with thyroid cancer (peak incidence) are between 44 and 49 years old. Men are more likely to develop it at a much older age
- being a woman – thyroid cancer is more common in women than in men, although it isn’t clear why. Researchers are looking into links related to pregnancy, the age your periods start or when you begin the menopause, as well as taking hormonal medication like oral contraceptives or HRT
- a family history of thyroid cancer – you’ve a higher risk of thyroid cancer if one or more of your parents, your brother or sister, son or daughter has it (known as a first degree relative)
- obesity – if you’re very overweight, this can increase your risk. We don’t know why but it’s thought to be linked to extra body fat sending signals to the rest of your body, telling it to divide its cells more often, which in turn can lead to cancer
- radiotherapy in childhood – your thyroid gland is sensitive to radiation and so thyroid cancer is more common in people treated with radiotherapy when they were a child, even if the cancer occurs many years later. Your risk of thyroid cancer isn’t increased if you’re routinely exposed to radiation through your work
- thyroid conditions – issues such as Hashimoto’s or a goitre can increase your risk, but there is no increased risk if you have an underactive or overactive thyroid gland
- acromegaly – a rare condition where your body produces too much growth hormone
- SLE (systemic lupus erythematosus) – an autoimmune condition. Studies suggest your risk of thyroid cancer is about 2 times more than the general population if you have SLE
- having had some types of cancer before – these include breast, testicular and oesophageal cancers, as well as non-Hodgkin lymphoma
The different types of thyroid cancer
There are 4 types of thyroid cancer. Most thyroid cancers don’t spread quickly and are rarely fatal.
- the most common type of thyroid cancer – UK statistics show about 90 out of every 100 thyroid cancers (approximately 90%) are this type. In the US, about 80% of thyroid cancers are papillary carcinoma
- it is more common in women aged between 30 and 60
it tends to grow slowly
- it sometimes spreads to lymph nodes in the neck, but has an excellent outlook even if this happens
- UK statistics show around 95 out of every 100 women (almost 95%) survive Papillary carcinoma for 5 years or more after diagnosis. Remember, this does not mean you will only live for five years, many people live much longer.
- most often diagnosed in middle aged people
- more common in women
- about 4 out of every 100 thyroid cancers diagnosed in the UK (just over 4%) are this type, while in the US follicular cancer makes up about 10 in 100 thyroid cancers
- it can sometimes spread through the blood to other organs, such as the lungs and bones
- it has good survival rates – UK statistics show around 90 out of every 100 women (almost 90%) will survive Follicular carcinoma for 5 years or more after diagnosis
Medullary thyroid carcinoma (MTC)
- this is a rare type of thyroid cancer
- UK statistics show only around 2 out of every 100 thyroid cancers (2%) are this type, in the US that figure rises slightly to 4%
- it is most often diagnosed in older people
- unlike other thyroid cancers, about a quarter of medullary thyroid cancers run in families, because of an inherited faulty gene
- it can spread to other parts of the body, such as the liver or the lungs
- around three quarters of people with MTC (approximately 75%) will survive for 5 years or more after diagnosis
Anaplastic thyroid carcinoma
- the least common type of thyroid cancer, less than 1% of thyroid cancers in the UK (2% in the US) are anaplastic but it is the most serious
- more common in women, it is often diagnosed in older people
- it is called ‘undifferentiated’ thyroid cancer because these cancer cells don’t look like normal thyroid cells
- it tends to grow more quickly than other types of thyroid cancer
- this type of thyroid cancer has the least positive outlook, but it is very rare
- although the hardest type of thyroid cancer to treat, it is still curable if caught at an early stage
Can thyroid cancer be cured?
In many cases, yes. In fact, papillary and follicular thyroid cancers (the most common types) have an overall survival rate of 85% over 10 years or more, in both the UK and the US, providing they’re caught and treated at an early stage.
Even if your thyroid cancer can’t be cured, the goal of your treatment will be to destroy or remove as much cancer as possible and then stop it from growing, spreading or returning for as long as possible.
It’s important to talk to your doctor about the type of thyroid cancer you have, as every cancer is different. They can give you a prognosis that’s personal to you.
When to see a doctor
Always see a doctor as soon as possible if you feel a lump in your neck or have any other symptoms of thyroid cancer listed above. The sooner you get your lump checked, the sooner you can rule out cancer or get the right treatment. Most lumps won’t be thyroid cancer and your doctor can help you work out what the cause is.
See your doctor urgently if you’ve any of the following symptoms:
- difficulty swallowing or breathing
- unexplained weight loss
- a hoarse voice or a change in your voice
- significant tiredness (fatigue)
How to prepare for a consultation
It can sometimes be difficult to remember everything you want to say to your doctor, especially if you’re anxious or nervous. Useful tips to help you get the most out of a consultation include:
- writing down your symptoms, when they started, if they’re getting worse, and anything that you’ve noticed makes them better or worse
- talking about any worries about cancer you may have
- letting your doctor know about any family history of thyroid problems or cancers
- taking a close friend or family member along with you, to help you remember what’s been said
- asking your doctor to explain anything you don’t understand, or to write things down for you if you think it’ll help
You can also use custom trackers and the journal in the Healthily app to keep track of your symptoms.
Your doctor will take a history of your symptoms and then do a physical examination, focusing on your neck. If they think you might have a thyroid problem they’ll organise some specific thyroid function tests, which may include:
- blood tests: These can be done at your doctor's surgery to check the levels of thyroid hormones in your blood
- ultrasound scan: A type of scan that uses sound waves to create an image of your thyroid gland and is completely painless
- biopsy: This is the only way to confirm that a thyroid lump is definitely cancer, a biopsy uses a tiny needle to suck out a small sample of fluid and cells from it. A specialist doctor will feel your thyroid lump and – using an ultrasound scan to guide them – put the needle into the lump. You can have a local anaesthetic injection to numb the area first, although the needle is so thin this is sometimes not needed. Once a sample has been obtained it’s sent to a laboratory for a specialist doctor (a pathologist) to examine it. If the biopsy shows you’ve got thyroid cancer, you may need extra tests such as CT scans or MRI scans to see if it’s spread to any other part of your body
Your thyroid cancer may then be given a ‘stage’ to show its size and how far it’s spread. This is called the TNM system:
- T (tumour) describes the tumour size, from 1 (smallest) to 4 (biggest)
- N (nodes) to show if the cancer has spread to nearby lymph glands, from either 0 (no spread) or 1 (spread)
- M (metastases) to show if the cancer has spread to another part of your body, from either 0 (no spread) or 1 (spread)
Knowing your TNM status helps your doctors decide on the best treatment for you.
How to cope with thyroid cancer
Being diagnosed with any cancer is a big shock – you’re likely to feel upset, frightened and confused. It can be very difficult coping with a cancer diagnosis so give yourself time to adjust. Be sure to talk to your family and friends about how you’re feeling, as well as to the healthcare professionals treating you.
Coming to terms with your diagnosis and getting through treatment
There are many ways to cope with the physical, emotional and practical worries of a thyroid cancer diagnosis. Specialist charities like Macmillan in the UK and the American Cancer Society in the US offer helplines and chatrooms where you can find support from others going through similar treatment.
You may experience some side effects – both mental and physical – from treatment. Here’s a guide to the basics:
Physical – eat as healthily as possible and remember to take exercise whenever you feel able to. Allow yourself to rest if you’re tired, especially when your treatment finishes, as you may feel most tired then (this usually gets better with time).
Emotional – talking to your family and good friends can provide emotional support. Let them or your health professionals know if you’d like to talk about what’s happening and how you feel.
If you’re concerned about worrying family or friends, or you think you’d find it easier to talk to someone who doesn’t know you, ask your doctor about psychological services available to you.
Practical– even when you’re having treatment, lots of practical things still need to be thought about. You might be worrying about work and money, childcare or benefits, sick pay and grants. If you can, get help with these as soon as possible after your diagnosis, so they don’t become a big issue later on when you may be feeling more tired.
You may qualify for government benefits, help with bills and housing costs, as well as for children's costs and other health expenses, so ask your doctor or the healthcare professionals treating you about these.
You can also reach out to charities such as Cancer Research UK, Macmillan or the American Cancer Society for advice and support.
The treatment for thyroid cancer depends on lots of factors, like the type of cancer you have, whether it’s spread and your health history
- surgery – often a first step with types of thyroid cancer, surgery can involve removing only the thyroid lobe with cancer in it – called a lobectomy – or removing the thyroid gland completely, called a total thyroidectomy. These are both major operations carried out under a general anaesthetic. If some or all of your thyroid gland is removed, you’ll need to take replacement thyroid hormone tablets for the rest of your life, to prevent symptoms of an underactive thyroid gland
- radioactive iodine – after surgery, you may have radioactive iodine treatment to kill any cancer cells that have been left behind. This involves swallowing radioactive iodine as a liquid or capsule, which then travels through your blood to kill any thyroid cancer cells. You'll be advised to cut down on iodine in your diet for 1 to 2 weeks before the treatment. Always tell your doctor if you think you may be pregnant as this type of treatment isn’t safe during pregnancy. Women should avoid getting pregnant for at least 6 months after having radioactive iodine treatment and men should avoid fathering a child for at least 4 months. If you’re breastfeeding, your doctor will advise you to stop a number of weeks before treatment starts
- radiotherapy – if radioactive iodine treatment isn’t suitable for you, or doesn’t work, then external radiotherapy may be used after surgery. This can reduce the risk of thyroid cancer coming back and also control symptoms if surgery can’t fully remove your cancer. Radiotherapy usually involves treatment at a hospital once a day from Monday to Friday with a break at weekends, for 4 to 6 weeks. Side effects can include nausea and sickness (vomiting), tiredness (fatigue), a dry mouth and a sore throat – these usually clear up a few weeks after you finish radiotherapy
- targeted therapies – these are a newer type of medicine that are sometimes recommended if you have thyroid cancer that has spread (metastasised) to other parts of your body and hasn’t responded to radioactive iodine treatment. Unlike chemotherapy, this type of treatment targets only cancer cells only and so doesn’t affect other healthy cells in your body. Examples of targeted therapies include cabozantib, sorafenib and lenvatinib
- chemotherapy – this type of treatment isn’t commonly used with thyroid cancer but is sometimes given to people with an anaplastic type that’s spread to other parts of the body. Chemotherapy is powerful anti-cancer medication given by mouth or intravenously. It kills cancer cells, but may also harm healthy ones. Common side effects include being sick, feeling very tired, losing your hair, having diarrhoea and having a very sore mouth
Remember, you’ll need lifelong thyroid checks, even after you've completed successful treatment.
Tip from a doctor
If you have to have radioactive iodine as part of your treatment plan, you may be advised to eat a low iodine diet for a few weeks beforehand. This is because it prepares your thyroid cells to absorb the treatment. You can return to your normal diet after you’ve had your treatment.
This means you should avoid foods with high levels of iodine such as:
- seafood, fish, and seaweed
- spinach, broccoli and other raw green vegetables
- biscuits and cakes made with eggs or butter
- salt with added iodine