What is Thyroid Cancer?

Thyroid cancer occurs when abnormal cancerous cells develop in the thyroid gland, a small butterfly-shaped gland at the base of the neck that produces hormones regulating heart rate, temperature, weight, and more. Thyroid cancer accounts for 2.2% of all new cancers, with over 44,000 cases estimated in the US for 2024. Fortunately, thyroid cancer is very treatable with early detection and proper care.

What is Thyroid Cancer and its Types?

The thyroid gland secretes thyroxine and triiodothyronine hormones that regulate vital bodily functions like heart rate, weight, body temperature, and digestion. Thyroid cancer develops when mutations cause thyroid cells to proliferate uncontrollably, forming malignant tumors.

There are four primary types of thyroid cancer:

  • Papillary – The most common form constituting 80% of cases. Has a favorable prognosis with proper treatment.
  • Follicular – The second most common type accounting for 10-15% of thyroid cancers. Slightly more aggressive than papillary cancer.
  • Medullary – Accounts for 3-5% of cases. Often hereditary and can spread more readily than other thyroid malignancies.
  • Anaplastic – The rarest and most advanced thyroid cancer with poor differentiation. Harder to treat and the prognosis is bleak.

Symptoms of Thyroid Cancer

Many thyroid cancers initially do not cause symptoms. As the nodule grows, it may lead to:

  • Neck swelling, tightness, or lump that gets bigger over time
  • Hoarseness, voice changes, or difficulty swallowing
  • Pain and tenderness in the neck and throat area
  • Chronic cough not from illness
  • Swollen lymph nodes in the neck


Who is at Risk? Causes and Risk Factors

Researchers do not fully understand the exact causes of thyroid cancer. However, certain factors are known to increase risk:

  • Radiation exposure – Particularly during childhood, such as from radiation therapy to the head or neck. Survivors of atomic blast radiation are also at higher risk.
  • Family history – Having a first-degree relative with thyroid cancer increases risk. Genetic conditions can run in families.
  • Diet low in iodine – Iodine is needed to produce thyroid hormones. Deficiency appears to stimulate abnormal cell growth.
  • Inherited genetic syndromes – Including multiple endocrine neoplasia, Cowden disease, and familial adenomatous polyposis.
  • Female gender – For unclear reasons, thyroid cancer is 3 times more common in women than men.
  • Age – Most cases occur in people between the ages of 25-65 years old.
  • Nodules – Benign thyroid nodules larger than 2cm may have a higher chance of becoming cancerous.
  • Diet and lifestyle – Obesity seems to be a risk factor for more serious thyroid tumors.

How Thyroid Cancer is Diagnosed

If thyroid cancer is suspected based on a physical exam, several tests can help confirm diagnosis:

  • Blood tests – Measure levels of thyroid-stimulating hormone (TSH) and thyroid hormones. Abnormal levels indicate thyroid dysfunction.
  • Ultrasound – Uses sound waves to create images of the thyroid gland and any nodules. Determines if nodules are solid or fluid-filled.
  • Biopsy – Removes cells from the nodule for examination under a microscope. Can definitively diagnose cancer.
  • CT/MRI scans – Provide detailed cross-sectional images of the neck/thyroid. Helps view the extent of tumors.
  • Radioiodine scan – Uses a radioactive tracer to detect thyroid tissue uptake. Useful for recurrent thyroid cancer.
  • Genetic testing – Identifies specific gene mutations, like RET mutations in medullary thyroid cancer.

These tests together build a comprehensive picture to enable accurate diagnosis and staging.

Treatment of Thyroid Cancer

Treatment options depend on the type and stage of thyroid cancer:

1. Surgery

This is the primary treatment for most thyroid cancers except anaplastic cancer. Options include:

  • Lobectomy – Removing the lobe with cancer and isthmus
  • Near-total thyroidectomy – Removing almost all thyroid tissue
  • Total thyroidectomy – Removing the entire thyroid gland

Lymph nodes may also be removed if cancer has spread.

2. Radioactive Iodine (RAI) Therapy

After surgery, RAI ablation can destroy any remaining thyroid tissue. The radioactive iodine pill concentrates in thyroid cells, destroying them.

3. Thyroid Hormone Therapy

Since thyroidectomy leads to hypothyroidism, daily oral thyroid hormone medication is required life-long to replace missing hormones.

4. Radiation Therapy

External beam radiation targets thyroid cancer with a focused radiation beam from outside the body. Used if surgery is not an option or for recurring cancer.

5. Chemotherapy

Chemotherapy cytotoxic drugs are administered intravenously to kill cancer cells in more advanced or metastatic thyroid cancers.

6. Targeted Therapy

For progressive thyroid cancers, targeted drugs (like lenvatinib, sorafenib, and pembrolizumab) inhibit specific mutations or proteins that spur cancer growth.


Outlook and Survival Rates

Prognosis varies substantially by cancer type:

  • Papillary: Over 95% of patients survive at least 5 years post-diagnosis when caught early.
  • Follicular: 10-year survival around 90%. Worse outcomes if extensively spread or invading blood vessels.
  • Medullary: 75% 10-year survival if limited to thyroid. Much lower if spread to other organs.
  • Anaplastic: Highly aggressive with low survival rates. Average life expectancy under 1 year.

Thyroid cancer can return in some cases, so lifelong monitoring is critical for early detection of recurrence.

Lifestyle Changes and Prevention

Being diagnosed with thyroid cancer and undergoing treatment can significantly impact quality of life. However, many people are able to manage the effects well. Ways to cope include:

  • Attending regular follow-up visits to monitor for recurrence. Blood tests and neck exams are standard.
  • Making dietary changes to decrease the risk of hypothyroidism after treatment. Increase iodine and selenium intake.
  • Joining a support group to share experiences. Thyroid Cancer Survivors’ Association has networks across the US.
  • Allowing extra time for adequate rest, nutrition, and physical activity. Pace yourself and listen to your body.
  • Practicing self-care techniques like meditation, journaling, and therapy to handle emotional ups and downs.
  • Being vigilant about symptoms returning, particularly for aggressive cancer types. Report any concerning or suspicious signs to your doctor promptly.

While thyroid cancer presents challenges, today’s treatment options and holistic support services allow many to continue enjoying life after diagnosis.


While a thyroid cancer diagnosis may seem daunting initially, it is one of the most treatable cancers, especially when identified at an early stage. Following physician recommendations for treatment, monitoring, diet, and lifestyle can help manage the condition and maintain an optimistic outlook. Support systems are available to help you through the cancer journey.

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