What Is Thyroid Cancer

Hello, reader. Hope you are healthy and happy. Are you in search of answers regarding what is thyroid cancer, the causes of thyroid cancer, and the treatment of thyroid cancer? If yes, then this article aims to provide you with answers. Let's start with cancer and then we will discuss thyroid cancer in detail.

Cancer is a deadly disease and everyone gets scared by just listening about it. According to the NHS, cancer is a medical condition where the cells start multiplying uncontrollably . These damaged cells then start growing or spreading to other body parts. This spreading of cancer cells is termed metastasis. 

Nowadays, cancer is becoming too common. As per statistics, almost 50% of the people in the UK will develop some form of cancer at any point in their life. This number is going to scare you, but you can reduce your chances of getting cancer by modifying your diet and lifestyle. Amongst the various types of cancer, the most commonly occurring ones in the UK are - 

  • Breast cancer 
  • Lung cancer 
  • Bowel cancer 
  • Prostate cancer


Thyroid gland is an endocrine gland located in the neck area.¹ It consists of two lobes. Endocrine means they secrete hormones that  regulate various body functions. The thyroid  gland secretes the hormones - 

  • Triiodothyronine (T3)
  • Thyroxine (T4) 
  • Calcitonin. 

Thyroid Stimulating Hormone (TSH) regulates the secretion of hormones T3 and T4. 

Thyroid hormones T3 and T4 are essential to maintain the metabolic rate of the body. 

Calcitonin hormone is essential to maintain the calcium levels in the blood. 

Thyroid cancer affects the thyroid gland. It is often diagnosed after the patient complains of a lump in the  neck or hoarseness of voice. As per statistics, only 1 in 20 lumps in the neck turn out to be thyroid cancer. Amongst all the cancer cases in the UK, only 1% of the population has thyroid cancer. So it is considered a rare form of cancer in the UK. Thyroid cancer is comparatively prevalent in individuals assigned female at birth (AFAB), individuals in their 30's, and individuals who are over the age of 60.

There are different types of thyroid cancer.¹, ²,³

Differentiated thyroid cancers are the types of thyroid cancer that start in the follicular cells of the thyroid gland. These follicular cells are responsible for producing and storing thyroid hormones. In these thyroid cancers, the thyroid gland retains most of the normal cells. They are easy to cure and have a low mortality rate.

Various types of differentiated thyroid cancers are - papillary thyroid cancer, follicular thyroid cancer, Hurthle cell thyroid cancer, and poorly differentiated thyroid cancer. 

Let's discuss them-

  1. Papillary thyroid carcinoma: Papillary thyroid cancer is the most common type of thyroid cancer. It is detected in 60-80% of thyroid cancer cases. It mostly affects AFAB and people below 40 years of age. Mostly, it spreads to the lymph nodes in the neck region. But the mortality rate is quite low
  2. Follicular thyroid carcinoma: Follicular thyroid cancer is the second most common thyroid cancer affecting 10-15% of people. It is mostly found in people over the age of 50. This cancer mostly spreads to bones and lungs
  3. Medullary thyroid carcinoma: Medullary thyroid cancer accounts for around 5-8% of the total thyroid cancer cases. This cancer mostly runs in families. It begins in the C cells of the thyroid gland which are responsible for the release of calcitonin hormone. So, an increase in the levels of this hormone might indicate medullary carcinoma
  4. Anaplastic thyroid carcinoma: Anaplastic thyroid cancer is a very rare and difficult-to-treat  thyroid cancer. It accounts for around 2% of the total thyroid cancer cases affecting mostly people over the age of 60. It grows as well as spreads quickly
  5. Hurthle cell carcinoma: Hurthle cell cancer is a rare form of thyroid cancer. Previously, it used to be diagnosed as follicular thyroid cancer. Since they behave in a different way to treatments, they are classified as separate types now. It mostly spreads to other body parts
  6. Poorly differentiated thyroid cancer: It is also very rare to occur. It is more aggressive compared to other mentioned differentiated thyroid cancers and these are also very difficult to treat
  7. Thyroid lymphoma: It is another rarely found thyroid cancer that  starts in the immune system cells of the thyroid gland
  8. Thyroid sarcoma: Another rare thyroid cancer. It begins in the connective tissue cells of the thyroid gland

Causes of thyroid cancer 

It is not clear what causes thyroid cancer, but there are certain factors that  increase the chances of being diagnosed with thyroid cancer. They are- ¹,² 

  • Gender: It is found that people assigned female at birth (AFAB) are more prone to thyroid cancer than people assigned male at birth (AMAB). It is due to the fact that they have more estrogen in their body which might be a reason for the prevalence of thyroid cancer
  • Genetics: Certain types of thyroid cancer such as medullary thyroid cancer and papillary thyroid cancer are mostly found to be occurring in families. So they have some genetic connection
  • Radiation: Individuals who have a history of any radiation exposure due to radiation therapy, especially in childhood are at higher risk of getting diagnosed with thyroid cancer. Radiation therapy might be required for  head and neck cancer
  • Acromegaly: A medical condition where the body produces excess growth hormones leading to overgrowth of the organs or the limbs
  • Thyroid disorders: Various thyroid disorders such as goiter or thyroiditis increase the chances of thyroid cancers
  • Familial adenomatous Polyposis (FAP): This is a bowel disorder that  is linked to increased chances of thyroid cancer
  • Iodine: Individuals who consume a low iodine diet are found to be more prone to thyroid cancer incidence
  • Obesity: As you know, obesity is a cause of  many disorders. Studies suggest that obesity can also make an individual prone to thyroid cancer

Signs and symptoms of thyroid cancer 

Mostly, thyroid cancers don't cause any change or symptoms in the early days. As the cancer progresses, various signs and symptoms can be noticed. They are¹, ²,³

  • A tiny lump or thyroid nodule in the neck 
  • Hoarseness of voice lasting a few weeks
  • Difficulty in swallowing food or drinks 
  • Pain in the neck area 
  • Sore throat 
  • Swollen lymph nodes in the neck 
  • Difficulty in breathing

When the thyroid cancer starts spreading to various body parts, there are different signs.

  • Loss of appetite 
  • Weight loss 
  • Nausea and vomiting 
  • Tiredness or fatigue

Management and treatment for thyroid cancer 

If you or anyone in your family is experiencing these symptoms, please contact your GP. They would arrange for some diagnostic tests and then treatment decisions can be taken. 

Various diagnostic methods for thyroid cancer are³

  • Blood tests: Blood samples are collected to check the levels of the thyroid hormones. This can give an idea about thyroid disorders
  • Biopsy: Not all thyroid nodules are cancerous. So, a biopsy needs to be done for confirmation. It is done using fine needle aspiration under the effects of local anaesthesia. This process is called Fine Needle Aspiration Cytology (FNAC). Sometimes, an ultrasound is required to confirm that the cells are collected from the thyroid nodule only
  • Radioiodine scan: This scan uses a radioactive form of iodine known as radioiodine. This scan can detect thyroid cancer and where it has spread. In this, radioactive iodine is ingested and after some specified time, the thyroid gland activity is checked to determine the thyroid cancer
  • Imaging scans: There are different imaging scans that  can help in detecting thyroid cancer. They are radioactive iodine scan, Positron Emission Tomography ( PET), and Computed Tomography ( CT)

If the thyroid nodules are found to be malignant or cancerous, then the specialist will explain the treatment options depending on the stage of the disease.³

  • Surgery: Surgery is the most common treatment for thyroid cancer. This decision depends on the size and location of the thyroid nodule. The surgeon  decides if the whole thyroid needs to be removed or only one lobe. Removal of the lobe is called lobectomy or hemithyroidectomy, whereas removal of the entire thyroid gland is called thyroidectomy. Any lymph nodes which are affected by cancer are also removed
  • Radioactive iodine therapy: In this, radioactive iodine I¹³¹ is given to patients in very high doses. After the radioactive iodine consumption, the patient is kept in an isolated room for 2-3 days depending on the radiation levels. This radioactive iodine kills the thyroid glands along with the cancer cells. It is considered a safe treatment
  • Radiation therapy: This is of two types - external radiation therapy and internal radiation therapy. In external radiation therapy, strong radiation beams are delivered to the cancer cells. Whereas, in internal radiation therapy, radioactive seeds are placed around the cancer cells
  • Chemotherapy: In this, medications are given as injections or pills to kill the cancer cells. Few thyroid cancer patients will require chemotherapy
  • Hormone therapy: In this, hormones are given to prevent the recurrence and spread of cancer cells 


How is thyroid cancer diagnosed?

Thyroid cancer can be diagnosed with blood tests, radioactive iodine, biopsy, or imaging scans.

How can I prevent thyroid cancer? 

A healthy  diet, abstaining from smoking and other abusive substances along with regular exercise is the key to a healthy life. These steps can prevent several diseases including thyroid cancer. Prophylactic thyroidectomy can be performed on  those who are at high risk of developing thyroid cancer.

What are the stages of thyroid cancer? 

According to the American Joint Committee on Cancer (AJCC), thyroid cancer is staged by the TNM system. 

  • T refers to the size of the tumour or cancer cells
  • N refers to the spread of cancer cells to nearby lymph nodes
  • M refers to metastases to distant sites

These stagings  are a bit complex to understand for non-medicals . Specialists use various details to assign a stage. There are stages  1- 4 of thyroid cancer.

What are the types of thyroid cancer? 

Thyroid cancer is classified into  various categories. Differentiated thyroid cancers are papillary thyroid cancer, follicular thyroid cancer, Hurthle cell thyroid cancer, and poorly differentiated thyroid cancer. Other types of cancer are medullary thyroid cancer, anaplastic cell cancer, thyroid lymphoma, and thyroid sarcoma.

Who are at risk  of thyroid cancer? 

Individuals in their 30s  and those over the age of 60 are more susceptible to thyroid cancer. People (AFAB) are 2-3 times more prone to thyroid cancer than people (AMAB).

How common is thyroid cancer? 

According to Cancer Research UK, around 3900 people are diagnosed with thyroid cancer every year. It is prevalent in people AFAB compared to people AMAB.

When should I see a doctor? 

It is better to see a doctor if you have any symptoms of thyroid cancer such as the presence of thyroid nodules/ lumps, hoarseness of voice, difficulty in breathing and swallowing, or an enlarged thyroid.


Thyroid cancer is a rare form of cancer in the UK. And most people manage to live a long life after diagnosis. But, if the cancer has metastasized to other body parts, then it might be difficult to treat. The most common sites of metastasis are the lungs, lymph nodes of the neck, bones, brain, liver, and skin.

Although it is not clear why some people get thyroid cancer, there can be few preventive measures. People who are at high risk of developing thyroid cancer due to genetics can get prophylactic thyroidectomy, which is the removal of the thyroid gland as a precautionary measure. 

People who live within a 10-mile  radius of a nuclear power plant can be given medications that block the effect of radiation.

Try maintaining a healthy lifestyle with a nutritious and healthy meal plan to keep disorders at bay. Getting a cancer diagnosis is scary, but thyroid cancer has lower mortality rates. 

I remember my head of department once saying that thyroid cancer is the least troublesome cancer of all the types of cancer. He said that if God ever asks that I want to give him  cancer, so choose which cancer you want; then say thyroid cancer. Thyroid cancer might require surgery and medication for a lifetime, but at least patients mostly recover well. 

Contact your GP if you have any symptoms. Early detection might increase your recovery chances.

There are chances of recurrence of cancer or metastasis at a later stage. So, don't forget to continue your medications and get follow-up scans as advised by your doctor.


  1. Thyroid cancer [Internet]. [cited 2023 Jan 27]. Available from: https://www.nhsinform.scot/illnesses-and-conditions/cancer/cancer-types-in-adults/thyroid-cancer
  2. Thyroid cancer - Symptoms and causes [Internet]. Mayo Clinic. [cited 2023 Jan 27]. Available from: https://www.mayoclinic.org/diseases-conditions/thyroid-cancer/symptoms-causes/syc-20354161
  3. Thyroid cancer: types, symptoms, causes & treatment [Internet]. Cleveland Clinic. [cited 2023 Jan 27]. Available from: https://my.clevelandclinic.org/health/diseases/12210-thyroid-cancer
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Simmi Anand

B.Sc. Nuclear Medicine, Manipal University
MBA Healthcare Services, Sikkim Manipal University

An experienced Nuclear Medicine professional with a passion for writing.

She is experienced in dealing with patients suffering from different ailments, mostly cancer.

Simmi took a career break to raise her daughter with undivided attention.

During this time, she fine-tuned her writing skills and started writing stories for her child. Today, Simmi is a published author of 'Story time with proverbs' series for young ones. She also enjoys writing parenting blogs on her website www.simmianand.com.

Simmi hopes to reignite her career as a medical writer, combining her medical knowledge with her zeal for writing to produce informative health articles for her readers.

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