Cancer of the Thyroid Explained

Transcription

1 Cancer of the Thyroid Explained Patient Information

2 Introduction This leaflet tells you about the condition known as thyroid cancer. We hope it will answer some of the questions that you or those who care for you may have at this time. It is not meant to replace the discussion between you and your surgeon, but helps you to understand more about what is discussed. What is cancer? The tissues and organs of the body are made up of cells. These age and become damaged and need to repair and replace themselves continually. Normally, this takes place in a structured and orderly fashion. Sometimes, this process goes wrong and cell division and repair gets out of control and a growth forms. This growth is called a tumour. A tumour may be benign (non-cancerous) or malignant (cancerous). In a benign tumour the abnormal cells develop to form a growth but do not spread, although the tumour can become large and press on other organs. A malignant tumour can spread to invade and possibly destroy surrounding tissues. Cancer cells can also spread to other organs in the body through the blood stream or the lymph glands. The cells can continue to grow and form a new tumour in another place, which is often called a secondary or a metastasis. There are many different kinds of cancer. They all behave differently, and are treated in many different ways. What is the role of the thyroid gland? The thyroid gland manufactures hormones which are secreted into the bloodstream where they act as messengers to affect cells and tissues in other parts of the body. Where is the thyroid gland? The thyroid gland is located in the neck. The gland is made up of two lobes (each about the size of half a plum) which are joined together in the middle by a piece of thyroid tissue called the isthmus. These two lobes lie on either side of your windpipe, with the gland as a whole lying just below your Adam s apple. 1

3 What does the thyroid gland do? The thyroid produces three hormones which are secreted into the bloodstream: Thyroxine, which contains four atoms of iodine and is often called T4. If little or no thyroxine is produced it can easily be replaced with medication. Triiodothyronin which contains three atoms of iodine and is often called T3. T3 influences all the activity of all cells and tissues in the body. If little or no T3 is produced it can easily be replaced with medication. Calcitonin, which is produced in response to increased levels of calcium in the blood. Calcitonin helps to lower calcium and phosphate levels in the blood by promoting their excretion. If little or no calcitonin is produced, the body still maintains calcium balance well without having to have the hormone replaced. What do the thyroid hormones do? Thyroid hormones affect the metabolism of your body cells, that is, they regulate the speed at which your body cell works. If too much are secreted the cells of the body work faster than normal and you have hyperthyroidism. However, if too little of the thyroid hormones are secreted then the body cells work slower than normal and you have hypothyroidism. How is the thyroid gland controlled? The thyroid is controlled by the pituitary gland, which lies underneath the brain within the skull and senses the levels of thyroid hormones (T4, T3 and calcitonin) in your bloodstream. If the levels drop below normal, the pituitary reacts by secreting a hormone called thyroid stimulating hormone which is often called TSH. TSH stimulates the thyroid gland to secrete more T3 and T4. Should the thyroid hormone levels rise above normal levels, then the pituitary senses this and stops secreting TSH and so the thyroid gland slows down its secretion of T3 and T4. 2

4 How is thyroid activity measured? In order to reach a diagnosis your consultant surgeon will need to assess your thyroid gland activity. Your doctor will be able to assess thyroid gland activity by taking a history of your symptoms and by a physical examination. However, to gain an exact level of thyroid hormone it is necessary to take a small sample of blood and measure the level of TSH and T4 in the laboratory. These tests are called thyroid function tests or TFTs. What are the parathyroid glands and how do they affect calcium levels? Another set of glands which work in conjunction with the thyroid, are the parathyroids. These are attached just behind the thyroid and there are usually four, although this can sometimes vary. The parathyroids produce parathyroid hormone (PTH) and this helps regulate the concentration of calcium in the blood. Normal calcium levels in the blood are essential for healthy bones, blood clotting, cardiac rhythm and cell function, as well as for general well-being. Are all thyroid cancers the same? No, there are four different types: Papillary cell carcinoma this is the most common thyroid cancer (80%) and is more common in younger people, particularly women. Follicular cell carcinoma this is a less common thyroid cancer (10%) and tends to occur in slightly older people than those with papillary cancer. Papillary and follicular tumours are called differentiated thyroid cancer, they resemble and act like normal thyroid cells and therefore concentrate iodine. They can be treated with surgery followed by radioactive iodine. Medullary cell carcinoma this is a rare cancer which can be hereditary and is usually treated by surgery. Ask your specialist about genetic counselling and he or she will arrange it. Anaplastic cancer a rare and aggressive form of thyroid cancer. 3

5 Most thyroid cancers are treatable and curable. However, some do recur, especially in the young and the elderly as they experience hormonal changes and in those who present with advanced disease. Recurrences occur at any time and can usually be treated successfully, so lifetime follow-up is important. What is the cause of thyroid cancer? The cause of thyroid cancer is unknown, however, a recognised risk factor is radiation exposure. It has been found in some people who have had external radiotherapy to the neck 10 or 20 years previously, as well as in Chernobyl children. Research into the causes of thyroid cancer is ongoing. Very rarely differentiated thyroid cancer runs in families. What are the symptoms of thyroid cancer? The commonest symptom is a painless lump in the thyroid which slowly increases in size. Other symptoms include: Difficulty in swallowing (dysphagia) due to the position of the thyroid gland close to the oesophagus (gullet). Difficulty in breathing (dyspnoea) due to the position of the thyroid gland close to the trachea (windpipe). Hoarseness of the voice Lump in the neck due to spread to lymph glands. Often there are no symptoms and it is found by accident. Hyperthyroidism (overactive thyroid) and hypothyroidism (underactive thyroid) are very rare in patients with thyroid cancer, as cancer cells do not generally affect thyroid hormone production. Cancer of the thyroid can be slow growing and it may be years before the symptoms present themselves. The diagnosis of thyroid cancer can take time. Some test may need repeating more than once to confirm your diagnosis and plan the right treatment. There are times when the results are inconclusive and the only way to obtain a definitive result is by having half of the thyroid gland removed and examined. 4

6 What happens after my diagnosis? When a diagnosis of thyroid cancer is made, each individual case, and after all the initial investigations have been performed is discussed at a multi-disciplinary team (MDT) meeting to consider which treatment(s) may be the best option. The members of the team may consist of: Maxillofacial consultant surgeons ENT consultant surgeons Consultant oncologists (cancer specialists) Consultant radiologists (doctors who interpret X-rays and scans) Consultant pathologists (doctors who examine tissues under a microscope to assist diagnosis) Consultant restorative dentists Head and neck clinical nurse specialists Speech and language therapists Dieticians Head and neck counsellor Following the MDT meeting your consultant surgeon and other members of your care team will meet with you and discuss the results of your investigations and the treatment options that should be undertaken in your case. Your surgeon will also answer any questions you have on the benefits and risks of these treatments. Once a treatment plan has been agreed with you, you should be able to start your treatment within 31 days. What treatment will I be offered? You may be offered surgery known as a thyroidectomy. More information about this surgery can be found in the leaflet Thyroidectomy. Surgery is usually the first line treatment for thyroid cancer. Generally, the whole thyroid gland will need to be removed (total thyroidectomy), though sometimes it will be possible to remove only one lobe (hemi or partial thyroidectomy). The extent of surgery depends on a number of factors such as your age, size of the lump and results of the above tests. The parathyroid glands are usually preserved. After a thyroidectomy, thyroxine tablets will be prescribed and need to be taken for the rest of your life. 5

7 Following surgery, what blood tests will I need? Regular blood tests will be required to monitor: Thyroid function Calcium Serum thyroglobulin Calcitonin (for medullary cancer only). Thyroid function tests are performed to check that hormone levels remain within normal limits and that TSH levels are suppressed. Eventually, you should only need a blood test once or twice a year to check that the thyroid-stimulating hormone (TSH) is suppressed and your thyroglobulin levels are undetectable. Thyroglobulin is a protein that is normally made only by the healthy thyroid gland but can also be produced by papillary or follicular thyroid cancer cells. As your thyroid has been removed, looking for thyroglobulin in your blood will indicate if there may be still some thyroid cancer cells. Thyroglobulin is therefore the tumour marker for papillary or follicular thyroid cancers. Calcitonin is the tumour maker in the blood for medullary thyroid cancer and is monitored on a regular basis. When you go home you may be taking calcium or vitamin D. You should contact your GP or treatment centre if you feel extremely tired, have feelings of pins and needles in hands/feet/face, if you have palpitations or feel shaky, become very over-active, or generally feel very unwell. This means you need to have your thyroxine or calcium levels checked, and your medication dose increased or decreased as the case may be. Once your body has settled you will be able to lead a normal life, but you will need to continue to take the thyroxine tablets for the rest of your life and to have your thyroid tests checked regularly. It is particularly important for pregnant women to have thyroid tests as their dose of T4 will need to be increased. Will I need to have radioactive iodine therapy? Many patients need to have radioactive iodine treatment after surgery for differentiated thyroid cancer. Your doctor will tell you if this is the 6

8 case. Radioactive iodine therapy is painless, it means taking either one or two capsule-type tablets, or a liquid, in a single dose. You should not feel sick or lose any hair, or have any other side effects with the doses that are administered. It is a very low dose of radiation but, for the safety of others, you would still need to come into hospital for two to four days and reduce your social contact. If you need radioactive iodine, you will be informed by your specialist consultant and given an information booklet before you start treatment: Radioactive Iodine Therapy Your Treatment Explained. Please read this booklet carefully. Most thyroid cancers are treatable and curable. Please contact your specialist treatment centre staff or your GP if you have any questions or concerns after reading this information. Together we can help you through your investigations, treatment and recovery. It is important that you make a list of all medicines you are taking and bring it with you to all your follow-up clinic appointments. If you have any questions at all, please ask your surgeon, oncologist or nurse. It may help to write down questions as you think of them so that you have them ready. It may also help to bring someone with you when you attend your outpatient appointments. For details of local cancer support groups and organisations, please ask your head and neck nurse. Glossary of medical terms used in this information: Calcitonin: a hormone produced by the thyroid gland. Too much of this hormone is produced in someone with medullary thyroid cancer. Chemotherapy: the treatment of cancer with drugs. Differentiated: the extent to which a cancer cell is similar to a normal body cell. Papillary and follicular tumours are called differentiated thyroid cancer because they resemble and act like normal thyroid cells. Follicular cell carcinoma: a less common form of thyroid cancer, 7

9 that tends to occur in slightly older people than those with papillary cancer. Hormone: a substance produced by an organ of the body that affects growth, development and activity. Isthmus: a narrow strip of tissue connecting two larger organs or part of an organ. Larynx: the voice box, where the vocal cords are located. Medullary thyroid cancer: a rare cancer which is sometimes, but not always, hereditary and usually treated by surgery. Metastasis: a new tumour that has spread from the original site, also known as a secondary. Oesophagus: the tube through which food passes on the way to the stomach, also known as the gullet. Papillary cell carcinoma: the most common thyroid cancer. It is more common in younger people, particularly women. Parathyroids: a set of glands just behind the thyroid. There are usually four and they work with the thyroid gland to produce hormones. Parathyroid hormone: also known as PTH, a hormone produced by the parathyroids which helps to regulate levels of calcium in the blood. Radiotherapy: X-ray treatment that uses high energy rays to damage or kill cancer cells. Thyroglobulin: a protein that is normally made only by the healthy thyroid gland but can also be produced by papillary or follicular thyroid cancer cells. Thyroid function tests: blood tests which measure levels of thyroid hormones in the blood stream, to assess activity levels of the throid 8

10 gland. Thyroid stimulating hormone: also known as TSH. A hormone produced by the pituitary gland which controls the thyroid gland. If thyroid hormones in the bloodstream are low then more TSH is produced. Trachea: a rigid tube that connects the mouth and nose to the lungs. Tumour marker: a substance found in the bloodstream which indicates the presence of a specific type of tumour. Local support groups Please visit on our website for details of local support groups: Local sources of further information You can visit any of the health/cancer information centres listed below: Heart of England NHS Foundation Trust Health Information Centre Birmingham Heartlands Hospital Bordesley Green Birmingham B9 5SS Telephone: Cancer Information and Support Centre Good Hope Hospital Rectory Road Sutton Coldfield B75 7RR Telephone: Sandwell and West Birmingham Hospitals NHS Trust The Courtyard Centre Sandwell General Hospital (Main Reception) Lyndon West Bromwich B71 4HJ Telephone: Fax:

11 University Hospital Birmingham NHS Foundation Trust The Patrick Room Cancer Centre Queen Elizabeth Hospital Edgbaston Birmingham B15 2TH Telephone: NHS Walsall Community Health Cancer and Palliative Care Services Walsall Palliative Care Centre Goscote Lane Goscote Walsall WS3 1SJ Freephone: About this information This guide is provided for general information only and is not a substitute for professional medical advice. Every effort is taken to ensure that this information is accurate and consistent with current knowledge and practice at the time of publication. We are constantly striving to improve the quality of our information. If you have a suggestion about how this information can be improved, please contact us via our website: This information was produced by Pan Birmingham Cancer Network and was written by Consultant Surgeons, Clinical Nurse Specialists, Allied Health Professionals, Patients and Carers from the following Trusts: Heart of England NHS Foundation Trust Sandwell and West Birmingham NHS Trust University Hospital Birmingham Foundation Trust Walsall Hospital NHS Trust We acknowledge the support of Macmillan in producing this information. Pan Birmingham Cancer Network 2010 Publication Date: November 2010 Review Date: November