Treatment for thyroid cancer
The type of treatment your doctor recommends will depend on the type and stage of the thyroid cancer, and your age and general health.
In some cases, your doctor may recommend closely monitoring the cancer, rather than having treatment straightaway. This approach is known as active surveillance. It usually involves regular ultrasounds and physical examinations.
There is good evidence that active surveillance is safe for small papillary thyroid cancers where there is no sign that the cancer has spread from the thyroid. It may be an option when the tumour is under 10 mm, isn’t causing any symptoms and is considered to be low risk.
Some people choose to have active surveillance if the possible side effects from treatment would have more impact on their quality of life than the cancer itself. Other people find that active surveillance makes them feel anxious and prefer to have treatment straightaway. Treatment can be considered at any stage if you change your mind or if the cancer grows or spreads. If you agree to active surveillance, your doctor will talk to you about the changes to look out for.
Surgery is the most common treatment for thyroid cancer. There are two main types of thyroid surgery. In some cases lymph nodes may also need to be removed.
Partial thyroidectomy – In a partial thyroidectomy (also called a hemithyroidectomy), only the affected lobe or section of the thyroid is removed. This surgery may be an option if the cancer is small and the other lobe looks normal on the ultrasound. It might also be used to diagnose thyroid cancer if a fine needle aspiration biopsy doesn’t provide a clear diagnosis. If cancer is found after a partial thyroidectomy, you may need further surgery to remove the rest of your thyroid.
Total thyroidectomy – Most people with thyroid cancer need to have a total thyroidectomy. This involves removing the whole thyroid (both lobes
and the isthmus).
Lymph node removal – With either type of thyroid surgery, nearby lymph nodes may also be removed to help work out staging or if the initial
scans show that the cancer has spread to them. This is called a neck dissection. Even if the cancer doesn’t appear to have spread, the nodes behind the thyroid are occasionally removed to reduce the risk of the cancer returning.
In very rare cases, the surgeon also removes other tissue near the thyroid that has been affected by the cancer.
Managing the side effects of thyroid surgery
Hoarse voice – Sometimes thyroid surgery affects the nerves to the voice box, which can make your voice sound hoarse or weak. This is often temporary and improves with time. Your singing voice may be affected. This is often temporary, but sometimes it is permanent. Most patients complain their voice gets tired after thyroid surgery, but this is usually temporary.
Sore neck – You will probably feel some pain or discomfort where the cut was made. You will be given pain medicines to manage this. The position you are placed in for surgery can sometimes give you a stiff neck and back. This is temporary, and neck massage and physiotherapy may help loosen the muscles in your neck. You can also try using a triangle-shaped pillow to support your neck after surgery and/or ask for pain medicine.
Eating and drinking – Most people start eating and drinking within a few hours after the operation. To help your body recover from surgery, you need
to be well nourished. Try to eat small amounts of healthy, nutritious food.
Painful swallowing – You will find it painful to swallow for a few days. Try to eat soft foods that are easy to swallow. Swallowing can feel stiff for
a few months, but usually gradually improves.
Scarring – You will have a horizontal scar on your neck above the collarbone. In most cases, the scar is about 5–7 cm long and is often in a natural skin crease. At first, this scar will look red, but it should fade and become less noticeable with time. Your doctor may recommend using special tape on the scar to help it heal. Keep the area moisturised to help the scar fade more quickly over time. Ask your pharmacist or doctor to recommend a suitable cream.
Activity levels – Most people return to their usual activities within a week, but some people need more time to recover. You will most likely need to avoid heavy lifting, vigorous exercise (such as running) and turning your neck quickly for a couple of weeks after surgery.
Mood changes – Changes in hormone levels may affect your mood. If you feel anxious or have panic attacks, let your doctor or nurse know as they may recommend medicines to help. Some people find meditation or relaxation techniques helpful.
Low calcium levels – You may have low blood calcium levels (hypocalcaemia) if surgery affects the parathyroid glands. This may cause headaches and tingling in your hands, feet and lips, as well as muscle cramps. Your doctor will do blood tests to check your calcium levels, and you may be
prescribed vitamin D and/or calcium supplements until your parathyroid glands recover. If the parathyroid glands don’t recover, vitamin D and/or calcium supplements need to be taken permanently. Calcium supplements should be taken at least two hours after your thyroid hormone replacement tablets.
For some people surgery is the only treatment they need. Others may require further treatment.
After the whole thyroid is removed your body will no longer produce the hormones that maintain your metabolism and you will be prescribed a hormone tablet to replace thyroxine (T4). You will need to take this hormone replacement tablet every day for the rest of your life.
For many people who have a partial thyroidectomy the remaining lobe will continue to make enough thyroid hormone which means they won’t need daily tablets.
Taking thyroid hormone tablets can have two roles:
Keeping your body’s metabolism functioning at a normal healthy rate – without hormone replacement medication, you will probably develop the symptoms of hypothyroidism, such as weight gain, constipation, brittle and dry hair and skin, depression, sluggishness and fatigue. In severe cases heart problems could occur.
Reducing the risk of the cancer coming back – taking the T4 hormone in tablet form stops your pituitary glands from producing another hormone called thyroid-stimulating hormone (TSH). It is thought that high levels of TSH may cause cancer cells to grow in other parts of the body. For this reason if the doctor thinks the cancer has a medium to high risk of recurring they will recommend you take a high dose of T4 to reduce the level of TSH. This is known as TSH suppression.
Finding the right dose
You’ll be carefully monitored when you start taking thyroid hormone replacement therapy. The starting dose of thyroxine (T4) is calculated based on your weight. You will have blood tests every 6–8 weeks to help your doctor adjust the dosage until it is right for you. Usually the initial dose is close to the correct dose and requires only small adjustments.
A small number of people may experience hypothyroidism or hyperthyroidism during the adjustment period. However, once you are taking the right dose you should not experience side effects.
Radioactive iodine (RAI) is a type of radioisotope treatment. Radioisotopes are radioactive substances given as capsules. Cancer cells absorb more radioisotope than normal cells which causes the cancer cells to die. Radioactive iodine is also known as I131 or radioactive iodine ablation treatment. RAI is usually given to destroy tiny amounts of remaining cancer cells or healthy thyroid tissue left behind after surgery.
Radioactive iodine treatment is suitable for people diagnosed with papillary or follicular thyroid cancer. RAI doesn’t work for medullary or anaplastic thyroid cancer because these types do not take up iodine. The radioactive iodine treatment often starts 4 weeks or more after surgery.
If you are pregnant you can’t have radioactive iodine treatment. If you are breastfeeding you will have to stop nursing before starting treatment.
Preparing for radioactive iodine treatment
Limiting foods high in iodine – a diet high in iodine makes RAI treatment less effective. You will need to start avoiding high-iodine foods two weeks before treatment. This includes foods such as seafood, iodised table salt, some dairy products, eggs, soy beans or soy-containing products and foods with E127 colouring. Your health care team can give you more information.
Raising TSH levels – for RAI treatment to work you need a high level of TSH. There are two ways to increase the TSH level in your body and the option recommended for you will depend on availability at your hospital and what is suitable for you.
Recombinant human thyroid-stimulating hormone (rhTSH) injections – you will be prescribed an injection of a man-made type of thyroid-stimulating hormone called recombinant human thyroid-stimulating hormone (rhTSH) or Thyrogen®. You will need an injection once a day for the two days before you start RAI treatment.
Thyroid hormone replacement – you stop taking your thyroid hormone replacement medicine for a few weeks. This often causes the side effects of hypothyroidism and some people find it difficult to cope with this, while others don’t notice any side effects.
Having radioactive iodine treatment
You will usually be admitted to hospital on the day of the radioactive iodine treatment. RAI treatment will make you radioactive for a few days and you may have to stay in hospital for all or part of this time. See below for an outline of the safety measures that will be in place while you are having treatment.
Once the radiation has dropped to a safe level you will be able to go home. If you are taking Thyrogen®, this is usually within 36–48 hours.
After radioactive iodine treatment
You will have a full body radioisotope scan. There is often a small amount of normal thyroid in your neck after surgery which will be destroyed by the RAI. The scan can also help detect if any cancer cells are left in the body. It may also show if the cancer has spread to your lymph nodes or other areas of your body such as your lungs or bones.
Your medical team, family members and friends will have to take precautions to limit their exposure to radiation. The safety measures vary for each hospital but usually include:
- keeping you in an isolated, shielded room
- restricting visitors to the room particularly children and pregnant women
- asking any visitors to stay two to three metres away from you
- limiting the time visitors can stay in the room
- measuring your radiation levels with an instrument called a Geiger counter usually done daily
- wearing gloves to clean up body fluids (e.g. urine, sweat, saliva and blood) and leftover food and drink.
Following these safety measures may make you feel frightened and lonely. It’s a good idea to take a book or something to do. Discuss any concerns you have with your doctors, nurses or a counsellor.
Safety measures at home
When you go home you may have to continue following some safety measures. For example you may have to sleep alone, wash your clothing separately, prepare your own food and take care with body fluids for a certain period of time. It’s usually required that you sit to urinate and you put the lid down and flush the toilet several times after use.
If these precautions are necessary your medical team will discuss them with you before treatment.
Usually, being temporarily radioactive is the only major side effect of RAI treatment. Other side effects are often caused by thyroid hormone withdrawal. This may cause you to feel thirsty, tired, nauseated or breathless. You may also have a dry mouth or have taste and smell changes for about 24 hours after treatment.
External beam radiation therapy (also known as external beam radiotherapy) uses a controlled dose of radiation to kill cancer cells or damage them so they cannot grow, multiply or spread.
Most people diagnosed with thyroid cancer do not need external beam radiation therapy, but it may be recommended in particular circumstances. In a small number of cases, it may be given:
- after surgery and RAI treatment if the cancer has not been completely removed or if there is a high risk of the cancer returning (recurrence)
- as palliative treatment to relieve symptoms such as pain caused by cancer that has spread to nearby tissue or structures
- to help control medullary or anaplastic thyroid cancer (because these types do not respond to RAI).
Side effects of external beam radiation therapy
Many people develop side effects during radiation therapy. Common side effects include feeling tired, difficulty swallowing, sore throat, dry mouth, and red, dry, itchy, sore or ulcerated skin. Most of these will disappear within a few weeks or months. Your treatment team can help you prevent or manage any side effects.
Targeted therapy drugs attack specific features of cancer cells to stop the cancer growing and spreading. The most common targeted therapy drugs used for thyroid cancer are tyrosine kinase inhibitors (TKIs). These drugs block the chemical messengers (enzymes) that help tell cancer cells to grow, multiply and spread.
If you have advanced thyroid cancer that hasn’t responded to RAI treatment, you may be offered a TKI such as lenvatinib or sorafenib. These drugs are given as a pill, which you take daily. You will usually keep taking the pills for several years.
Other TKIs may be available on clinical trial. Talk with your doctor about the latest developments and whether you are a suitable candidate.
Side effects of targeted therapy
The most common side effects of TKIs include diarrhoea, skin rash, bleeding and high blood pressure. In some people, TKIs can affect the way the heart and kidneys work. Some TKIs can also cause tenderness, tingling and blisters on the skin of the palms and soles.
It is important to tell your doctor about any side effects immediately. If left untreated, some side effects can become life-threatening. Your doctor will explain what to watch out for, and will monitor you throughout treatment.
Chemotherapy is the use of drugs to kill cancer cells or slow their growth. While chemotherapy is not often used to treat thyroid cancer, it may sometimes be used to treat advanced thyroid cancer that is not responding to RAI treatment or targeted therapy. It may also be used in combination with radiation therapy to treat anaplastic thyroid cancer.
The drugs are usually given by injection into a vein (intravenously) or as tablets. You will probably have several treatment sessions over a few weeks – your treatment team will work out the schedule.
Side effects of chemotherapy
The side effects of chemotherapy will vary depending on the drugs used. Common side effects include fatigue, nausea, appetite loss, diarrhoea, hair loss, mouth sores and anaemia. You may also be more likely to catch infections.
Most people with thyroid cancer respond well to treatment and do not need to access palliative care services. However, people at any stage of advanced thyroid cancer may benefit from palliative treatment.
Palliative treatment helps to improve people’s quality of life by managing symptoms of cancer without trying to cure the disease. The treatment you are offered will be tailored to your individual needs. It may include radiation therapy, chemotherapy, targeted therapy or other medicines.