What is thyroid cancer?

Thyroid cancer originates in the thyroid gland, a small, butterfly-shaped gland located at the base of the neck, just below the Adam’s apple. The thyroid gland produces hormones that regulate your heart rate, blood pressure, body temperature, and weight. Thyroid cancer is arguably common in Singapore, particularly among women—it's the eighth most diagnosed cancer among women in the country.

There are several types of thyroid cancer:

Papillary thyroid cancer: this is the most common type, accounting for about 80% of all thyroid cancers. It typically grows slowly and is usually found in one lobe of the thyroid gland.
Follicular thyroid cancer: this type makes up about 10-15% of thyroid cancers. It also tends to grow slowly but can spread to other parts of the body, such as the lungs or bones.
Medullary thyroid cancer: accounting for about 4% of thyroid cancers, this type can be more aggressive and can sometimes be linked to genetic syndromes.
Anaplastic thyroid cancer: this is a rare and very aggressive form of thyroid cancer, accounting for about 2% of cases. It tends to grow and spread very quickly.

Thyroid cancer is also classified into stages, which describe the extent of the disease and help determine the appropriate treatment. The stages range from I to IV:

Stage	Description
Stage I	A small tumour (usually less than 2 cm in size), only in the thyroid, has not spread elsewhere
Stage II	The tumour may be larger than 2 centimetres but is still confined to the thyroid, or it may be smaller but has started to spread to nearby tissues.
Stage III	The cancer has spread beyond the thyroid to nearby lymph nodes or tissues in the neck.
Stage IV	The cancer has spread to distant parts of the body, such as the lungs or bones.

What causes thyroid cancer?

Thyroid cancer occurs when there are genetic mutations within the cells of the thyroid gland. These mutations lead to uncontrolled cell growth and division. Under normal circumstances, thyroid cells grow, divide, and die in a controlled manner. However, mutations can activate oncogenes, which promote cell growth and division, or deactivate tumour suppressor genes, which normally control cell growth and cause abnormal cells to die. This disruption in the balance between cell growth and death results in the accumulation of abnormal cells, forming a tumour.

In some cases, these abnormal cells can invade nearby tissues and spread to other body parts (metastasis). The specific mechanisms behind these genetic changes can vary depending on the type of thyroid cancer but it generally involves alterations in pathways that regulate cell proliferation, differentiation, and apoptosis (programmed cell death).

What are the symptoms of thyroid cancer?

Thyroid cancer often presents with a variety of symptoms, which can vary depending on the type and progression of the disease. Common symptoms include:

A lump in the neck
Neck pain
Difficulty swallowing
Hoarseness or voice changes
Difficulty breathing
Persistent cough
Swollen lymph nodes

While these symptoms can indicate thyroid cancer, they can also be associated with other, less serious conditions. It is important to consult a healthcare professional if any of these symptoms are present for an accurate diagnosis and appropriate treatment.

Is thyroid cancer painful?

Thyroid cancer itself typically does not cause pain in the early stages. The main sign you might notice is a painless lump in your neck. However, as the tumour progresses or if it affects surrounding structures, it can cause discomfort or pain in the neck or throat.

Who is at risk of thyroid cancer in Singapore?

Certain individuals are at higher risk of developing thyroid cancer due to a combination of genetic, environmental, and lifestyle factors. Key risk factors include:

Gender and age: women are three times more likely to develop thyroid cancer than men. While thyroid cancer can occur at any age, the risk peaks for women in their 40s and 50s and for men in their 60s and 70s.
Radiation exposure: exposure to high levels of radiation, particularly during childhood, significantly increases the risk of thyroid cancer. This includes radiation therapy for cancers in the head and neck area (link to service page) and exposure to radioactive fallout from nuclear accidents or tests.
Family history: having a family history of thyroid cancer or other thyroid diseases increases the risk. Certain inherited genetic syndromes, such as multiple endocrine neoplasia (MEN) types 2A and 2B, familial medullary thyroid carcinoma, and familial adenomatous polyposis (FAP), are also associated with a higher risk of developing thyroid cancer.
Iodine deficiency or excess: both insufficient and excessive iodine intake can affect thyroid function and increase the risk of thyroid cancer. Iodine is essential for thyroid hormone production, and imbalances can disrupt normal thyroid cell function.
Personal history of thyroid conditions: individuals with a history of thyroid conditions, such as goitre (enlarged thyroid), thyroid nodules, or chronic thyroiditis (inflammation of the thyroid), have an increased risk of developing thyroid cancer.
Genetic mutations: certain genetic mutations, such as those in the RET gene, are linked to an increased risk of medullary thyroid cancer. Other gene mutations may also play a role in the development of different types of thyroid cancer.
Other factors: although less well-defined, some studies suggest that obesity, certain dietary factors, and a sedentary lifestyle may contribute to an increased risk of thyroid cancer.

While these risk factors can increase the likelihood of developing thyroid cancer, having one or more of them does not necessarily mean a person will develop the disease. Conversely, some people with thyroid cancer may not have any known risk factors.

How is thyroid cancer diagnosed?

At NC Tan, we utilise a range of advanced methods to ensure accurate and timely detection of thyroid cancer. Here is how we approach the diagnostic process:

Physical examination: our doctor begins with a thorough physical examination, carefully checking your neck for any lumps or swelling. We also take the time to discuss your symptoms, medical history, and any family history of thyroid or other cancers.
Blood tests: we conduct blood tests to measure levels of thyroid hormones (T3 and T4) and thyroid-stimulating hormone (TSH). These tests help us understand your thyroid function. Additionally, we may test for calcitonin and carcinoembryonic antigen (CEA) levels if medullary thyroid cancer is suspected.
Ultrasound: our doctor may opt for ultrasound to visualise the thyroid gland and nearby structures. It helps in assessing the size, shape, and characteristics of thyroid nodules, distinguishing between solid and cystic nodules, and evaluating if the nodules have suspicious features.
Fine-Needle Aspiration (FNA) Biopsy: for a more definitive diagnosis, our specialists perform an FNA biopsy under ultrasound guidance. A thin needle is used to extract cells or fluid from the thyroid nodule, which are then meticulously examined by our skilled pathologists for the presence of cancer cells.
Imaging tests: if further evaluation is needed, we may recommend additional imaging tests such as a computed tomography (CT) scan, magnetic resonance imaging (MRI), or positron emission tomography (PET) scan. These advanced imaging techniques help us assess the extent of cancer spread to other parts of your body.
Radioiodine scan: in certain cases, we use a radioiodine scan to gain more insights. After administering a small amount of radioactive iodine, we use a special camera to detect the radioactivity, highlighting areas of the thyroid and any abnormal tissues that absorb iodine differently.
Molecular testing: for complex cases, particularly when FNA biopsy results are unclear, we conduct molecular testing of the biopsy sample. This approach detects specific genetic mutations or markers associated with different types of thyroid cancer, guiding us in diagnosis and treatment planning.

What are the treatment options for thyroid cancer in Singapore?

At NC Tan, we offer personalised and comprehensive treatment options for thyroid cancer. Here are the primary treatment options we provide:

Surgery: surgery is often the first line of treatment for thyroid cancer. Our surgeons perform procedures such as thyroidectomy, which involves removing part or all of the thyroid gland. Depending on the extent of the cancer, we may also remove nearby lymph nodes to ensure thorough treatment.
Radioactive iodine therapy: for certain types of thyroid cancer, we offer radioactive iodine therapy. This treatment involves ingesting a small amount of radioactive iodine, which selectively targets and destroys the remaining cancer cells in the thyroid and other parts of the body. Our team carefully monitors this treatment to maximise its effectiveness while minimising side effects.
Thyroid hormone therapy: after thyroid surgery, thyroid hormone therapy is often necessary to replace the hormones that the thyroid gland would normally produce. This therapy also helps to suppress the growth of any remaining cancer cells. Our endocrinologists work closely with you to adjust hormone levels and ensure optimal health.
External beam radiation therapy: in some cases, we use external beam radiation therapy to target and destroy cancer cells. This treatment is particularly useful for cancers that do not respond to radioactive iodine therapy or have spread beyond the thyroid. Our radiation oncologists utilise advanced techniques to deliver precise doses of radiation while sparing healthy tissue.
Chemotherapy: while not commonly used for thyroid cancer, chemotherapy may be recommended for advanced cases that do not respond to other treatments.
Targeted therapy: for certain types of thyroid cancer with specific genetic mutations, targeted therapy may be utilised. These medications specifically target cancer cells with minimal impact on normal cells.

At NC Tan, we prioritise your well-being and work collaboratively to develop a treatment plan that best suits your individual needs. If you have been diagnosed with thyroid cancer, please schedule an appointment with us to discuss your treatment options.

Frequently Asked Questions

Is thyroid cancer serious?

Thyroid cancer can be serious, but it is often treatable, especially when detected early. Most types of thyroid cancer have high survival rates, and with appropriate treatment, many patients can lead healthy, normal lives.

Is thyroid cancer 100% curable?

Thyroid cancer is highly treatable, and many patients achieve complete remission, especially with early detection and proper treatment. However, while it often has a high survival rate, not all cases are 100% curable, and ongoing monitoring may be necessary.

Can thyroid cancer recur after treatment?

Yes, thyroid cancer can recur even after successful treatment. Regular follow-up appointments and monitoring are crucial to detect any recurrence early and manage it promptly.

What lifestyle changes should I make after thyroid cancer treatment?

After treatment, maintaining a healthy diet, staying active, managing stress, and adhering to prescribed medications can support recovery and overall well-being. Regular check-ups are also important for monitoring thyroid function and overall health.

How does thyroid cancer affect my thyroid hormone levels?

Thyroid cancer and its treatment, particularly surgery and radioactive iodine therapy, can impact thyroid hormone levels. Patients may need lifelong thyroid hormone replacement therapy to maintain normal hormone levels and support metabolic functions.

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