Thyroid cancer occurs when the cells of the thyroid gland begin to grow abnormally. Thyroid cancer is more common among women than men. Initially, it may not have any symptoms. However, as the disease progresses, it may cause symptoms, such as pain and swelling in the neck region. About 90% of thyroid tumours are reported to be benign.
Although the incidence of thyroid cancer is on the rise in recent years, it is one of the cancers with excellent survival rates.
There are multiple types of thyroid cancers; some are aggressive, while some progress slowly.
- 1. Papillary Thyroid Cancer:Papillary thyroid cancer begins in the follicular cells, which synthesise and store thyroid hormones. This is the most prevalent type of thyroid cancer. Papillary thyroid carcinoma can strike at any age, although it is most common in adults between the ages of 30 and 50. These cancers tend to spread to the lymph nodes present in the neck.
- 2.Follicular Thyroid Cancer:Follicular thyroid cancer develops from the follicular cells as well. It is most common in adults over the age of 50. Hurthle cell carcinoma is a subtype of follicular thyroid cancer, and it is a far more aggressive form of thyroid cancer. This thyroid cancer type can spread to nearby lymph nodes and blood vessels.
- 3.Anaplastic Thyroid Cancer:Also called undifferentiated carcinoma, this thyroid cancer type is found to spread quickly and is extremely challenging to treat. Adults aged 60 and above are more likely to develop anaplastic thyroid cancer.
- 4.Medullary Thyroid Cancer:This cancer type begins in C cells, whose function is to produce the hormone calcitonin. Higher calcitonin levels in the blood could be a sign of early-stage medullary thyroid cancer.
Other rare types of thyroid cancers include thyroid lymphoma and thyroid sarcoma.
Early on, thyroid cancers may not show any symptoms. However, as the disease progresses, it can lead to the following symptoms:
- A lump (nodule) on the neck that can be felt through the skin
- Voice change or hoarseness
- Swallowing difficulties
- Ear, neck, and throat pain
- Swollen lymph nodes in the neck
- Frequent cough without cold
- Breathing difficulties
- Constant wheezing
In recent years, researchers have identified a few key risk factors that are strongly associated with thyroid cancer, and they are:
- Radiation Exposure:Exposure to radiation, particularly during childhood, raises the risk of thyroid cancer.
- Gender:Thyroid cancer is more common in women than in men.
- Family history:Thyroid cancer is more likely to occur in people who have a family history of goitre (enlargement of the thyroid gland) and other thyroid disorders.
- Iodine Deficiency:There is an increased risk of some types of thyroid cancer if there is an iodine deficiency in the diet.
Particular Health Conditions:Thyroid cancer is more likely in people with the following conditions/diseases:
- Hashimoto’s thyroiditis
- Thyroid adenoma
- Cowden’s syndrome
- Familial adenomatous polyposis
- Genetics:Inheriting a faulty gene causes about 2 out of every ten medullary thyroid carcinomas (MTCs), according to the reports.
Most of the thyroid lumps are non-cancerous. However, it is not wise to ignore them. If there is any lump or swelling or pain in the neck region that lasts for more than two weeks, it is important to consult a specialist. Following are the common test methods used for detection and diagnosis of thyroid cancers:
a. Physical Exam:The doctor examines the thyroid gland for lumps (nodules). He/she may also look for abnormal growths or swelling in the neck and adjacent lymph nodes.
b. Blood Tests:Thyroid-Stimulating Hormone (TSH) levels in the blood may be checked if thyroid problems are suspected. TSH levels that are too high or too low indicate that the thyroid is not functioning properly.
c. Ultrasound Scan:To get clear images of the thyroid gland and surrounding tissues, an ultrasound scan may be indicated. Thyroid nodules that are too tiny to feel can be seen in this image. The majority of nodules that are filled with fluid are not cancerous. Solid nodules could be cancerous.
d. Thyroid scan:During a thyroid scan, the patient is made to swallow a small amount of radioactive substance, which is usually radioactive iodine; this is ingested and carried through the bloodstream. On a scan, the thyroid cells, which absorb the radioactive substance, can be seen easily. Those tissues that absorb the radioactive substance in larger quantities appear as bright spots and are called hot nodules. The majority of these hot nodules are not cancerous; however, they may also indicate thyroid cancer in a few cases. Further tests may be recommended for definitive diagnosis.
e. Biopsy:One way to obtain a definitive diagnosis of thyroid cancer is through a biopsy. A pathologist examines a sample of thyroid tissue under a microscope for cancer cells.
Thyroid cancers are usually treated with a multimodal approach. At HCG, we have a multidisciplinary team that carefully studies the patient’s health condition and accordingly devises the best suitable treatment plan, which could either involve one or more treatment modalities.
a. Surgery:Surgery involves the removal of the tumour along with a small portion of healthy tissue (margin) around it. Various surgical options available for thyroid cancer are:
- 1. Lobectomy: This surgery removes the cancer-affected lobe of the thyroid gland.
- 2. Near-total Thyroidectomy: This surgery removes both the thyroid lobes except for a small portion of thyroid tissues.
- 3. Total Thyroidectomy: This surgery removes the thyroid gland entirely.
If the thyroid cancer has spread to nearby lymph nodes, they may be removed as well.
b. Thyroid Hormone Therapy: Thyroid hormone therapy is a hormone replacement treatment wherein synthetic thyroid hormones are administered to improve the abnormally low levels of natural thyroid hormones. Thyroid hormone therapy, which is usually given in pill form, is essential to maintain the bodily functions that are regulated by the thyroid hormones. This treatment is recommended after the surgery.
c. Radioactive Iodine (Radioiodine) Therapy:Radioactive iodine therapy is a form of radiation therapy wherein a radioactive isotope of iodine is given to kill the tumour cells. Radioactive iodine treatment is usually given after surgery to kill the residual cancer cells. The radioiodine is administered either in liquid or pill form.
d. External Beam Radiation Therapy:During radiation therapy, high-energy radiation beams are used to target the tumour precisely and destroy the cancer cells. Here, radiation is delivered from an external source (a linear accelerator), unlike radioactive iodine therapy. Usually, radiation therapy is given after the surgery to enhance the effectiveness of the overall treatment.
e. Chemotherapy:Chemotherapy uses powerful drugs to destroy cancer cells. These drugs travel throughout the body and kill the cancer cells wherever they are present. In the case of thyroid cancer, chemotherapy is recommended when cancer has metastasized. Chemotherapy can be administered both orally and intravenously. It may also be recommended to ease pain and other symptoms caused by the disease in terminally ill patients.
Frequently Asked Questions
1. Are thyroid cancers treatable?
Thyroid cancer is one of the highly treatable cancers with excellent survival rates. However, the disease prognosis depends on the stage at which the disease is diagnosed. Early-stage thyroid cancers have relatively higher survival rates with excellent quality of life when compared to advanced-stage thyroid cancers.
Therefore, it is important to not ignore any lump, swelling or pain in the neck region that lasts for more than two weeks.
2. Does thyroid cancer come back?
Although thyroid cancers can be successfully treated, stringent follow-up care is necessary since most thyroid tumours grow slowly and can relapse even after 10 to 20 years. A thorough history and physical examination, with special attention to the neck area, as well as specific blood tests and other testing methods, are all recommended during follow-up visits. These follow-up visits aid in the prevention and early detection of relapse.
3. Can thyroid cancer spread to other parts of the body?
If left undiagnosed in early stages, thyroid cancers can spread from the thyroid gland to nearby lymph nodes and surrounding organs, such as the esophagus and windpipe. In advanced stages, these cancers can potentially migrate to the lungs or bones, too.
4. Is hyperthyroidism a symptom of thyroid cancer?
No, hyperthyroidism or an overactive thyroid gland does not always indicate thyroid cancer. However, a few studies have found that a small percentage of thyroid cancer patients have a history of benign thyroid conditions.