A thyroid cancer is a tumor or abnormal growth of cells which arises from the tissues of the thyroid gland, which is a butterfly shaped gland in your neck which produces hormones required for bodily functions. There are several types of thyroid cancers in existence, of which papillary carcinoma of the thyroid is the most common to affect individuals and accounts for about 70%-80% of all cases. The other types include follicular carcinoma which makes up about 20% of the thyroid cancers, anaplastic thyroid cancer, medullary thyroid cancer and thyroid lymphoma or sarcoma.
Thyroid cancer is said to be three times more common in females than in males and makes up about 3.8% of all new diagnosed cases of cancer. World over you have around 53,990 cases of thyroid cancer being diagnosed each year, with 40,900 of them being women and 13,090 cases being men. Thyroid cancer has a five year survival rate of 97%.
What Are the Symptoms of thyroid Cancer?
Thyroid cancer may go unnoticed in its early stages because of the lack of the symptoms during this time, as it develops very slowly. And even if you do develop any symptoms, they are more likely to be non-specific ones such as:
- Change in voice with development of hoarseness
- Neck pain or throat pain
- Difficulty in swallowing
- A mass in the throat or neck which is gradually getting bigger
- Enlarged/swollen lymph nodes in the neck region
If you have developed any of these symptoms and you are worried, then you should definitely see your doctor at the earliest.
What causes thyroid cancer?
Although a specific cause for the development of thyroid cancer has not been identified, many factors have been associated with an increased risk of developing thyroid cancer. And these include:
- Genetic predisposition – especially if you have a family history of carrying the RET gene
- Exposure to radiation treatment of the neck in your childhood
- If you have developed benign conditions of the thyroid such as solitary nodules or goiter
What tests are used to diagnose thyroid cancer?
Diagnosis of thyroid cancer is done using physical examination of the patient as well as investigations. Although the physical examination will be helpful in diagnosing a condition related to the thyroid gland, the exact diagnosis of cancer can be made using investigations such as:
- Blood tests - which will measure circulating levels of thyroid hormone including T3, T4 and TSH in your blood. But these tests do not specifically indicate a cancerous condition of the thyroid, as the hormone levels can be indicative of hyperthyroidism (overactive thyroid gland) or hypothyroidism (underactive thyroid gland)
- Ultrasound scan of the thyroid gland - which is pain free investigation carried out by running a probe over your neck, which takes about 20 minutes, and produces images of the organs present in your neck. Helping the doctor conclude if the lump in your neck if a solid one or is filled with fluid, and also if any of the adjacent lymph nodes have been affected.
- Biopsy - a biopsy is a test which will confirm if the mass in your neck is actually made of cancer cells or not. Your doctor will want to remove a sample of tissue from the lump in your neck by inserting a small needle and drawing out some cells, which is called fine needle aspiration and is the most common type of biopsy which is taken. These cells will then be observed under the microscope to determine if they are cancer cells or not.
- Radioisotope scan – this test will help determine how active your thyroid gland is. Here a small dose of radioactive iodine is injected into a vein in your arm, and the uptake of this radioactive substance by the thyroid gland is measured in order to determine the activity.
What is the treatment for thyroid cancer?
Treatment of thyroid cancer cannot be standardized, and has to be individualized according to each patient. Therefore you need a specialized team of professionals to care for a patient diagnosed with thyroid cancer and this includes a GP, Endocrinologist, Endocrine Surgeon, ENT surgeon, Nuclear Medicine Specialist, Cancer Nurses, as well as other healthcare workers such as dietician and physiotherapist.
The treatment modalities available for thyroid cancer currently include surgery, radiotherapy, chemotherapy, radioactive iodine treatment and hormone replacement therapy. Most patients will receive a combination of these treatments.
- Thyroid surgery – where your thyroid gland is removed partially or completely along with adjacent lymph nodes on occasion
- Radiotherapy – using high energy X-rays is given externally, on most occasions following thyroid surgery if the cancer had spread to the adjacent tissue
- Radioactive iodine treatment – which is a form of internal radiation where a tablet containing radioactive iodine is swallowed by the patient, which then goes and destroys the thyroid tissue gradually. This is really useful in destroying any cancer cells that may remain in your body after the surgery
- Chemotherapy – is most often used as a form of treatment if iodine treatment does not work
- Hormone replacement therapy – where the thyroid hormone is replaced using a tablet, especially if you have undergone a total thyroidectomy
Palliative care is aimed at symptom relief and slowing down the spread of the cancer, when nothing else can be done to completely cure the condition. Keeping the patient as comfortable as possible with pain relief is an important factor. Palliative care also makes use of chemotherapy, radiotherapy and various other drugs to achieve this.
What is the Prognosis of thyroid cancer?
The outcome of thyroid cancer is dependent on many factors such as the type of thyroid cancer, the stage of the disease and the general health condition of the patient. But most thyroid cancers have a very good prognosis, especially if detected early.
Screening for and prevention of thyroid cancer
There are no screening methods currently available for thyroid cancer.
There are no specific methods to prevent the development of thyroid cancer. But family members of an affected individual can have themselves checked for the presence of a mutated gene, and then consider having their thyroid gland removed before cancer develops.