Thyroid Cancer: Symptoms, Diagnosis and Treatment
What Is Thyroid Cancer?
Thyroid cancer happens when abnormal cells grow in the thyroid—a small, butterfly shaped gland at the base of the neck, just below the Adam’s apple. The thyroid plays an important role in the body. It helps control things like energy levels, heart rate, body temperature and how fast the body uses energy.
Thyroid cancer is the ninth most common cancer worldwide. In the United States, about 45,000 people are diagnosed each year.
The good news is that thyroid cancer is one of the most treatable and survivable cancers. The overall five-year survival rate is approximately 98 percent. This means most people diagnosed with thyroid cancer are alive five years after their diagnosis.
Who Gets Thyroid Cancer?
Thyroid cancer can affect people of any age, but it is most often found in adults in their 50s. Women are more likely than men to develop it.
Several factors can increase risk, including exposure to radiation (especially during childhood), a family history of thyroid cancer or certain genetic conditions, and, in some cases, obesity or low iodine intake.
Even if you have one or more of these risk factors, it does not mean you will develop thyroid cancer—it only means your risk may be higher.
Signs and Symptoms
Most thyroid cancers do not cause symptoms in the early stages. It is often discovered in one of the following ways:
- A lump or nodule in the neck felt during a routine physical exam
- An incidental finding on imaging done for another reason (such as a CT scan of the neck or a carotid ultrasound)
- Enlarged lymph nodes in the neck
When symptoms do occur, they may include:
- A lump that is seen or felt in the front of the neck
- Hoarseness or other voice changes
- Difficulty swallowing
- Neck or throat pain
- Persistent cough not related to a cold
- Difficulty breathing
It is important to note that thyroid nodules are extremely common. Ultrasound can detect them in up to 68 percent of healthy adults, and most of those are benign or not cancerous. Only about 10 percent of thyroid nodules turn out to be cancerous.
How Is Thyroid Cancer Diagnosed?
If a lump (nodule) is found in the thyroid, doctors use these steps to check if it could be cancer:
- Ultrasound: This imaging test uses sound waves to create pictures of the thyroid. It helps doctors look closely at the nodule and see if it has features that might be concerning.
- Biopsy (fine-needle aspiration): A very thin needle is used to take a small sample of cells from the nodule. These cells are then checked under a microscope. This is the best way to tell if the nodule is cancer.
- Blood tests: A blood test checks how well the thyroid is working. In some cases, another test may be done to look for a specific type of thyroid cancer.
- Advanced testing (if needed): If the biopsy results aren’t clear, special tests can look at the genes in the cells to help determine whether the nodule is likely cancerous or not.
A note about screening:
The U.S. Preventive Services Task Force (USPSTF) recommends against screening for thyroid cancer in adults who have no symptoms or risk factors. This is because widespread screening has been shown to lead to overdiagnosis (the detection of very small, slow-growing cancers that would never cause harm) without improving survival rates.
How Is Thyroid Cancer Treated?
Treatment depends on the type, size and stage of the cancer, as well as the patient's overall health and preferences.
Surgery
Surgery is the primary treatment for nearly all thyroid cancers.
- Total thyroidectomy: Removal of the entire thyroid gland.
- Lobectomy (partial thyroidectomy): Removal of half of the thyroid.
Nearby lymph nodes may also be removed if cancer has spread to them.
Radioactive Iodine (RAI) Therapy
After surgery, many people are treated with radioactive iodine to destroy remaining thyroid tissue or cancer cells.
Thyroid Hormone Therapy
After total thyroidectomy, patients must take thyroid hormone medication (levothyroxine) for the rest of their lives.
External Beam Radiation Therapy
This type of radiation may be used when cancer cannot be completely removed by surgery or does not respond to radioactive iodine.
Targeted Therapy and Other Medications
- Multikinase inhibitors (lenvatinib, sorafenib, cabozantinib)
- Targeted therapies based on genetic mutations
- Immunotherapy such as pembrolizumab
Active Surveillance
For very small cancers, observation without immediate surgery may be an option.
What Happens After Treatment?
- Blood tests: Monitor thyroglobulin levels for recurrence
- Neck ultrasound: Check for returning cancer
- Whole body scans: Used when needed
Most patients have an excellent long-term outlook. Even if cancer returns, it is often treatable.
Living with Thyroid Cancer
- Lifelong medication: Daily hormone replacement
- Follow-up care: Regular visits with specialists
- Emotional well-being: Support is important
- Quality of life: Most people live full, active lives
Key Takeaways
- Thyroid cancer is highly treatable with about a 98 percent survival rate.
- Papillary thyroid cancer is the most common type.
- Surgery is the primary treatment.
- Targeted therapies expand options for advanced cases.
- Long-term follow-up is essential.
- Routine screening is not recommended without symptoms.
Frequently Asked Questions
What are early signs of thyroid cancer?
A lump in the neck is the most common early sign, though many cases have no symptoms at first.
Is thyroid cancer treatable?
Yes, it is one of the most treatable cancers with a very high survival rate.
Do thyroid nodules mean cancer?
No, most thyroid nodules are benign. Only a small percentage are cancerous.
Should I get screened for thyroid cancer?
No, screening is not recommended for people without symptoms or risk factors.
