Thyroid Cancer from Detection to Treatment


What Is Thyroid Cancer?

Thyroid cancer begins in the thyroid gland, a butterfly-shaped gland in the neck that produces hormones controlling metabolism, heart rate, and growth.

Most thyroid cancers are papillary or follicular types.

Less common types include medullary and anaplastic thyroid cancer.

Thyroid cancer is often slow-growing and highly treatable, especially if detected early.


1. Initial Evaluation

Common Symptoms:
A lump or swelling in the neck
Hoarseness or voice changes
Difficulty swallowing or breathing
Persistent cough not due to infection
Neck pain | sometimes radiating to jaw or ears

Doctors assess risk factors such as:
Family history of thyroid or endocrine cancers
Past radiation exposure to the head/neck
Genetic syndromes
Rapidly growing neck lump or firm, fixed nodule


2. Physical and Neck Examination

Doctor palpates the thyroid gland and neck lymph nodes.
Notes size | mobility | consistency | and tenderness of nodules.
If a suspicious lump is felt ➧ proceed to imaging.


3. Imaging and Scanning Tests

Neck Ultrasound
Detects nodules and evaluates their characteristics.
Assesses lymph nodes in the neck for metastasis.
Used to guide fine-needle biopsy if needed.

CT Scan or MRI
Determines extent of local invasion or spread to lungs, trachea, or mediastinum.
Used in more advanced cases.

Radioiodine | I-131 | Whole Body Scan
Performed after thyroid surgery to check for remaining or metastatic thyroid tissue.
Thyroid cells | including cancer | absorb radioactive iodine, allowing visualization.

PET-CT Scan
Used in advanced or recurrent cancers, especially non–iodine-avid ones.


4. Diagnostic Procedures

Thyroid Function Tests
Measures TSH | T3 | and T4 levels.

Fine-Needle Aspiration Biopsy
Gold standard for diagnosis.
A thin needle extracts cells from the thyroid nodule | ultrasound-guided.
Pathologist examines for cancer cells.

Molecular Testing
Detects gene mutations | BRAF, RET, RAS - helps determine cancer type and guide therapy.


5. Types of Thyroid Cancer

Papillary carcinoma | 80-85%
Slow-growing, good prognosis

Follicular carcinoma | 10-15%
Slightly more aggressive

Medullary carcinoma | 3-4%
May be genetic | MEN2; secretes calcitonin

Anaplastic carcinoma | <2%
Very aggressive and fast-growing


6. Staging | AJCC / TNM

I - Localized within thyroid
II - Spread to nearby tissues or lymph nodes
III - Larger tumor or multiple lymph nodes involved
IV - Spread to distant organs


7. Multidisciplinary Treatment Planning

Team includes:
Endocrinologist
Head & Neck Surgeon / ENT Surgeon
Medical Oncologist
Radiation Oncologist
Nuclear Medicine Specialist
Pathologist and Genetic Counselor


8. Treatment Options

Surgery

Lobectomy | Partial Thyroidectomy
Removal of one thyroid lobe.

Total Thyroidectomy
Removal of the entire thyroid gland.

Neck Dissection
Removes affected lymph nodes in neck | if metastasis confirmed.

After surgery, patients must take lifelong thyroid hormone replacement | Levothyroxine | to maintain metabolism and suppress TSH | which can stimulate cancer regrowth.

Radioactive Iodine Therapy

Given after surgery to destroy any remaining thyroid tissue or microscopic cancer cells.
Used mainly for papillary and follicular cancers.
Not effective for medullary or anaplastic types.

Procedure:
Patient stops thyroid medication temporarily to raise TSH.
Radioactive iodine capsule is swallowed.
Radiation targets residual thyroid cells.
Isolation for 1-3 days | to limit exposure to others.

External Beam Radiation Therapy

Used when:
Cancer cannot be completely removed surgically.
Cancer recurs locally and is not iodine-sensitive.

Chemotherapy

Rarely used; mainly for anaplastic or metastatic medullary cancers.
Drugs: Doxorubicin, Cisplatin, or Tyrosine Kinase Inhibitors like Lenvatinib, Sorafenib, Cabozantinib.

Targeted Therapy & Immunotherapy

For advanced/refractory cancers:
RET inhibitors ➧ Selpercatinib, Pralsetinib.
BRAF/MEK inhibitors ➧ Dabrafenib + Trametinib.
Immunotherapy ➧ Pembrolizumab in selected cases.


9. Supportive & Rehabilitative Care

Thyroid hormone replacement | Levothyroxine | to regulate metabolism.

Calcium and vitamin D supplements if parathyroids removed or injured.

Speech and swallowing therapy if nerves affected during surgery.

Emotional support for coping with long-term follow-up and body image changes.


10. Follow-up and Monitoring

After Treatment:
Every 3 months for first 2 years
Every 6 months for next 3 years
Annually after 5 years

Includes:
Neck ultrasound and physical exam
Thyroglobulin blood test ➧ Marker for papillary/follicular cancer recurrence
Calcitonin and CEA tests ➧ For medullary cancer
Whole-body iodine scan or PET-CT if recurrence suspected