Cells are the basic building blocks of the tissues and organs of our body. Usually, these cells divide to make new cells in a controlled manner, and beyond a point, the cells are replaced with new cells. This is how our bodies grow, heal and repair. Sometimes, this orderly growth of cells can go wrong due to the mutation or sudden change in the genes which control how cells behave. This can make the cells divide abnormally producing more and more abnormal cells, forming a lump called a tumour. These cells cannot stay together, can easily detach from each other and spread via direct contact, lymphatics and bloodstream to different organs in the body.
The thyroid is a small butterfly-shaped gland present in front of the neck. It produces a hormone called thyroxine which affects the growth, development and function of almost all the cells in the body.
Thyroid cancer accounts forn1.6 % of all cancers in India( 1 to 2 per 1 lakh population). Thyroid cancer ranks 19th among all cancers in India.
Most thyroid cancers occur sporadically without any particular reason that one can find. However, some patients may have a family history and a history of head and neck radiation
Thyroid cancers present mainly as swelling in front of the neck, which moves up and down with swallowing. The other common symptoms are swellings in the neck, inability to swallow, difficulty breathing, and hoarseness of voice. They may rarely present as bone pain, loss of weight and appetite.
A detailed clinical history and a thorough clinical examination are made for each patient. Ultrasound-guided biopsy/ FNAC is taken to confirm the diagnosis of thyroid cancer. Ultrasound for the neck is also done to confirm the diagnosis. Ultrasound for the neck is also done to look out for similar structures in the neck.
Fine Needle Aspiration Cytology (FNAC) is a test that helps to know whether the patient has cancer or not. In this test, a needle is injected multiple times into the tumour or the lymph nodes under negative pressure, and few cells are aspirated into the syringe. If the tumour or the lymph node is not easily palpable, it can be done under ultrasound guidance. The microscope analyses these cells to look out whether the tumour is benign or malignant. This is an office procedure, and this can be done in the clinic. There can be minimal discomfort for a few hours after the procedure.
Other rare cytology reports are Atypia of unknown significance, Follicular lesion of unknown significance and anaplastic thyroid cancer. Treatment decisions will be made on a case to case basis.
The other tests that may be required are
Thyroid cancers are most commonly treated by surgery. Depending on each case, we might use other methods such as TSH suppression therapy and Radioiodine therapy. Rarely radiotherapy, chemotherapy and targeted therapy may be used in advanced disease.
Hemithyroidectomy is the removal of one half of the thyroid gland(one lobe of the thyroid gland along with isthmus). It is done for benign diseases, Follicular adenoma and selected early cancers. The advantage of hemithyroidectomy is that patients can avoid lifelong thyroxin and calcium supplementation.
Total thyroidectomy is the removal of the entire thyroid gland. It is the most common procedure done for thyroid cancers.
Neck dissection is the removal of the lymph nodes which are at high risk of cancer spread. Neck dissection is done when the lymph nodes are detected by clinical examination and ultrasound. In medullary carcinoma thyroid, the central compartment neck dissection is done along prophylactically (Even if nodes are not detected clinically or by ultrasound).
The scar after a thyroidectomy operation is horizontal and merges along with the skin folds in the neck. They usually heal very well. Rarely they may present with hypertrophic scars, which might need some massaging of the scar and silicon sheets.
Facts at a glance about surgery and post-operative instructions: ( May vary from person to person)
Type of anaesthesia | : General Anaesthesia |
---|---|
Surgery time | : 2 - 3 hours |
Hospital stay | : 2 - 5 days |
Mobilisation | : 1st day |
Drain removal | : 1st or 2nd day |
Normal diet | : 1st day |
Suture removal | : No suture removal required |
Self-care | : 5 days |
Full recovery | : 2 weeks |
Return to work | : 3 weeks |
Radioactive Iodine therapy is given to patients after thyroidectomy surgery to prevent a recurrence. The thyroid gland and thyroid cancers preferentially tend to take up iodine compared to the other parts of the body. Radioactive material tagged with iodine is called Radioactive Iodine therapy. This helps to identify and destroy any residual thyroid gland or thyroid cancer. All patients with Intermediate and high risk will need Radioactive Iodine therapy. Risk stratification is based on age at diagnosis, biopsy report after total thyroidectomy, uptake in low dose scan and thyroglobulin values.
No other special preparation is required.
Radioactive iodine is usually taken by mouth. As the dose given is low in low-risk patients, the patient will be discharged the same day after taking the scan. As the dose given is higher in intermediate or high-risk patients, the patient may be admitted in isolation, monitored and discharged after a few days once the dose falls to the permissible level.
The adverse effects of radioactive iodine therapy usually subside in a few days
The possibility of survival depends on the cancer stage, site of involvement, grade of the tumour and the patient's compliance with the treatment. The survival of patients with cancer is generally denoted as 5-year survival, wherein the percentage of people surviving at the end of 5years after a cancer diagnosis is noted down. This is given in the tabular column below.
5-year survival rate for Thyroid cancers.
Papillary | Follicular | Medullary | Anaplastic | |
Limited to thyroid | 100% | 100% | 100% | 31% |
Beyond thyroid or Nodal disease | 99% | 96% | 90% | 12% |
Distant spread | 78% | 63% | 39% | 4% |
TSH ( Thyroid stimulating Hormone) is a hormone produced in the body that helps grow thyroid cancers. This production of TSH can be suppressed by giving higher doses of thyroxine hormones. The TSH level is monitored in frequent intervals, and the dose is adjusted accordingly.
TSH ( Thyroid Stimulating Hormone)
TSH is a hormone produced in the body that can facilitate the growth and spread of thyroid cancers. We would like to keep it at a low level. We would like to monitor this level every 3 months for the first 2 years and then periodically lifelong.
Thyroglobulin & Anti thyroglobulin antibody
These are tumour markers that help to identify thyroid cancer recurrence early.