Thyroid Cancer – Symptoms and Causes
Overview
Thyroid cancer develops when cells in the thyroid gland grow abnormally and form tumors.
The thyroid is a butterfly-shaped gland at the base of the neck that produces hormones controlling important body functions like heart rate, blood pressure, body temperature, and weight.
When thyroid cells undergo DNA mutations, they multiply uncontrollably instead of dying like normal cells. These abnormal cells can form tumors, invade nearby tissues, and sometimes spread to other parts of the body.
Types of Thyroid Cancer:
- Papillary Thyroid Cancer: Most common type, typically affecting people aged 30-50.
- Follicular Thyroid Cancer: Usually occurs in people over 50
- Anaplastic Thyroid Cancer: Rare and aggressive type, typically in adults over 60
- Medullary Thyroid Cancer: Uncommon, with about 30% linked to genetic syndromes
Risk Factors
Several factors may increase the risk of developing thyroid cancer:
- Gender: Women are three times more likely to develop thyroid cancer than men.
- Radiation Exposure: Previous radiation therapy to the head or neck region.
- Genetic Factors: Certain inherited genetic syndromes.
- Age: Risk varies by cancer type, with different types affecting different age groups.
Signs and Symptoms
Early thyroid cancer often causes no symptoms. As it grows, you might notice:
- A lump in the neck that can be felt through the skin
- Voice changes, including hoarseness
- Difficulty swallowing
- Pain in the neck or throat
- Swollen lymph nodes in the neck
Diagnosis Process
Diagnosing thyroid cancer typically involves multiple steps:
- Physical examination of the neck and thyroid
- Blood tests to check hormone levels
- Ultrasound imaging of the thyroid
- Biopsy to examine thyroid tissue
- Sometimes genetic testing to identify hereditary causes
For confirmed cases, additional tests may determine if the cancer has spread beyond the thyroid:
- Blood tests for tumor markers
- CT scans or MRI
- Nuclear imaging tests like radioiodine whole-body scans
Treatment Options
Treatment approaches depend on the cancer type, size, and stage:
| Cancer Size | Common Approach |
|---|---|
| Under 1 cm | May only require observation with regular monitoring |
| Larger | Often requires surgical intervention |
Surgical options include removing part of the thyroid (partial thyroidectomy) or the entire gland (total thyroidectomy). Other treatments might include:
- Thyroid hormone therapy
- Alcohol ablation
- Radioactive iodine
- Targeted drug therapy
- External radiation therapy
- Chemotherapy (in some cases)
Living with Thyroid Cancer
A thyroid cancer diagnosis can be challenging. These strategies may help:
- Learn about your condition to make informed care decisions
- Connect with other survivors for emotional support
- Focus on overall health through:
- Eating a diet rich in fruits and vegetables
- Getting adequate rest
- Incorporating physical activity when possible
The good news is that most thyroid cancers respond well to treatment. The prognosis for most patients is excellent, especially when the cancer is detected early.
Improved imaging technology has led to increased detection of small thyroid cancers during scans done for other conditions. These incidentally discovered cancers are typically small and respond favorably to treatment.
Signs and Changes
As thyroid cancer grows, it may not show early signs. However, over time, you might notice:
- A lump you can feel on your neck
- Tight-feeling shirt collars
- Voice changes or hoarseness
- Trouble swallowing
- Swollen neck lymph nodes
- Neck and throat pain
When to Visit a Healthcare Provider
If you notice any concerning signs on your neck or changes in your voice or swallowing, make an appointment with your doctor. Early detection can lead to better treatment outcomes.
What Causes Thyroid Cancer
Thyroid cancer begins when cells in the thyroid gland develop DNA changes. These changes tell cells to grow quickly and live longer than they should.
The extra cells form tumors that can spread to nearby tissues and sometimes to distant parts of the body.
Doctors classify thyroid cancer into several types based on how the cells look under a microscope. The type helps determine treatment options and outlook.
Thyroid Cancer Types
These cancers start in the follicular cells that make and store thyroid hormones. Under a microscope, they look somewhat similar to normal thyroid cells.
Papillary Thyroid Cancer
- Most common type
- Typically affects people ages 30-50
- Usually responds well to treatment
- Often spreads to neck lymph nodes
- Most are slow-growing, but some can be aggressive
Follicular Thyroid Cancer
- Rare type that usually affects people over 50
- Rarely spreads to neck lymph nodes
- May spread to lungs and bones in aggressive cases
- Requires different treatment approaches than papillary cancer
Hurthle Cell Thyroid Cancer
- Previously grouped with follicular cancer
- Now considered its own type
- More aggressive behavior
- Can grow into nearby structures
- May spread to distant body parts
- Responds differently to standard treatments
Poorly Differentiated Thyroid Cancer
- Rare and more aggressive
- Often doesn’t respond well to typical treatments
- Requires more intensive management
Anaplastic Thyroid Cancer
This rare form grows very quickly and can be hard to treat. It usually affects people over 60 and causes severe symptoms:
- Rapidly worsening neck swelling
- Breathing difficulties
- Swallowing problems
While challenging to treat, treatments can help slow its progression.
Medullary Thyroid Cancer
This rare type begins in C cells, which make the hormone calcitonin. Blood tests showing high calcitonin can help detect it early. Two main forms exist:
- The sporadic form appears unpredictably.
- Hereditary forms are linked to changes in the RET gene that parents can pass to children.
The inherited form may be part of two syndromes:
- Familial medullary thyroid cancer
- Multiple endocrine neoplasia type 2 (which increases risk for other cancers too)
Other Rare Types
Some very uncommon cancers can also affect the thyroid:
| Type | Origin |
|---|---|
| Thyroid Lymphoma | Immune system cells in the thyroid |
| Thyroid Sarcoma | Connective tissue cells in the thyroid |
For most people with thyroid cancer, doctors can’t identify a specific cause for the DNA changes that led to cancer development. Research continues to better understand what triggers these changes.
Risk Factors
Several factors can increase your chance of developing thyroid cancer:
Gender differences: Women face a higher risk than men. This may be linked to estrogen levels, which are typically higher in females.
Radiation exposure: People who have had radiation treatments to the head and neck area have an increased risk of developing thyroid cancer later in life.
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Genetic factors: Some inherited conditions can raise your risk, including:
- Familial medullary thyroid cancer
- Multiple endocrine neoplasia
- Cowden syndrome
- Familial adenomatous polyposis
Both medullary and papillary thyroid cancers sometimes run in families. If you have relatives with thyroid cancer, you might have a higher risk.
When Thyroid Cancer Comes Back or Spreads
Recurrent Thyroid Cancer
Most thyroid cancers have low recurrence rates, especially common types like papillary and follicular thyroid cancer. However, some patients experience cancer returning even after their thyroid has been completely removed.
This happens when cancer cells spread beyond the thyroid before surgery. Recurrence typically occurs within the first five years after diagnosis.
Your doctor can assess your specific risk based on your cancer’s characteristics. The good news is that recurrent thyroid cancer generally has positive outcomes and responds well to treatment.
When thyroid cancer returns, it might appear in:
- Lymph nodes in the neck
- Small thyroid tissue fragments left after surgery
- Distant areas like lungs or bones
Metastatic Thyroid Cancer
Most thyroid cancers don’t spread beyond the thyroid. However, in some cases, cancer cells travel to other body parts either at initial diagnosis or after treatment.
Common sites where thyroid cancer spreads:
| Location | Frequency |
|---|---|
| Neck lymph nodes | Most common |
| Lungs | Common |
| Bones | Less common |
| Brain | Rare |
| Liver | Rare |
| Skin | Rare |
Doctors use imaging tests like CT scans and MRIs to check for spread when first diagnosing thyroid cancer. After treatment, your healthcare team might schedule follow-up appointments that include specialized nuclear imaging scans.
These scans use radioactive iodine and special cameras to detect thyroid cancer cells that may have spread.
Ways to Prevent Thyroid Cancer
People with inherited genes that raise the risk of medullary thyroid cancer have important options to consider.
Preventive thyroid removal surgery (prophylactic thyroidectomy) might be recommended for both adults and children with these genetic markers. This surgery removes the thyroid before cancer develops.
Meeting with a genetic counselor is an essential step. These specialists can:
- Explain your personal cancer risk
- Discuss available prevention options
- Help you make informed decisions about treatment
Safety Measures for Nuclear Plant Neighbors
People living within 10 miles of nuclear power plants can take specific precautions. In the United States, potassium iodide medication is sometimes available to nearby residents.
This medication works by blocking radiation’s effects on the thyroid gland during a reactor emergency.
If you live near a nuclear facility and have safety concerns, contact your local emergency management department. They can provide information about:
- Emergency procedures
- How to obtain protective medication
- What to do in case of an incident
Scientists still don’t understand what causes most thyroid cancer gene changes, making prevention difficult for average-risk people.
