Facts and figures about thyroid cancer
Thyroid cancer is quite rare; about 2,700 new cases are diagnosed each year in the UK. Higher incidence in women; male to female ratio is approximately 1:2.5. Age related, the highest incidence in women is in the 40-60 years age group and the highest incidence in men is in the 60-80 years age group.
Risk factors include benign thyroid disease, radiation exposure, first degree relative diagnosed with thyroid cancer, low iodine levels in diet, obesity, diabetes, bowel condition FAP (familial adenomatous polyposis) and acromegaly.
Most common type is Papillary (80-85%); other types are follicular, medullary and anaplastic.
Thyroid cancer symptoms
- A lump usually at the base of the neck/ lumps or swelling elsewhere in the neck.
- Persistent hoarse voice.
- Persistent sore throat.
- Difficulty in swallowing (dysphagia).
Diagnosis of thyroid cancer
Investigations may include:
- Physical examination.
- Blood tests (will include thyroid function test to check thyroid hormone levels).
- Ultrasound scan.
- Needle biopsy- a small amount of tissue will be taken for analysis.
Thyroid cancer treatment
Depends on several factors:
- The type of tumour.
- The stage of the cancer.
- General health.
- Age and fitness.
Surgery is usually the first treatment for papillary, medullary and follicular thyroid cancer; this may be partial or complete removal of the thyroid (thyroidectomy) depending on the size of the tumour. During surgery some neck nodes nearest to the tumour may be removed but if disease is found in the neck nodes then all of the nodes on one or both sides of the neck may be removed to reduce the risk of recurrence (neck dissection).
Post-operative radioactive iodine or external radiotherapy may be advised to reduce possible recurrence. Curative surgery is rare for anaplastic tumours as they have usually spread into the surrounding tissues at the time of diagnosis.
Radiotherapy is frequently used in the treatment of thyroid cancer. This may be radioactive iodine or external radiotherapy depending on the type and stage of disease. Radioactive iodine may be advised post-surgery for papillary or follicular tumours to reduce the risk of recurrence.
External radiotherapy is sometimes used to treat papillary, follicular or medullary tumours if surgical removal was incomplete and to treat medullary or anaplastic tumours if they recur after initial treatment. External radiotherapy is also used to treat papillary or follicular tumours if they recur and do not respond to radioactive iodine.
Intensity modulated radiotherapy (IMRT) has proved to increase the effectiveness of treatment by enabling the disease to be targeted very accurately hence reducing dose to healthy tissue and reducing side effects.
Image guided radiotherapy (IGRT) also enables the radiotherapy to be precisely delivered to the intended area which reduces potential radiation dose to healthy tissues and allows the radiography team to monitor any changes in the patients shape. This is important as head and neck patients often lose weight during treatment which can affect the aligning of the radiotherapy treatment. In some cases, it may be necessary to make a new headshell and replan the patient’s radiotherapy treatment.
It is important to achieve precise alignment for accuracy in delivering radiotherapy, therefore in most cases it is necessary for a ‘headshell’ to be produced. This is achieved by using a specialised thermoplastic material which can be heated in warm water and then is laid over the patient’s face to form an accurately fitting customised shell which can then be used for the planning CT scan and for all the radiotherapy treatments.
It is a painless procedure which is clearly explained by the radiographers prior to the procedure. Surgery or radiotherapy for anaplastic tumours is often palliative to help control symptoms.
Chemotherapy is occasionally used to treat advanced disease or recurrences.