Thyroid cancer is found in certain thyroid nodules, but most nodules are benign.
Types of Thyroid Cancer
Papillary Thyroid Cancer
- Most common cancer in endocrinology (85% of thyroid cancers)
- Very slow growing and curable
- More common in people who have had radiation therapy earlier in life
- Variants include:
- Hurthle Cell
- Tall Cell
- Hobnail
- Insular
- Columnar
- Follicular
Follicular Thyroid Cancer
- 12% of thyroid cancers
- Slow growing
- More associated with older patients, especially in areas without iodine in the diet
- Has variants requiring special attention
Medullary Thyroid Cancer
- 1-2% of thyroid cancers
- Usually hereditary, can be associated with syndromes like MEN
- Some cases are random
- Treated with surgery and occasionally radiation therapy
- Calcitonin serves as a tumor marker
Anaplastic Thyroid Cancer
- 0.01% of thyroid cancers
- Rare and extremely aggressive
- Associated with specific gene mutations
- High mortality rate
- Often detected at an advanced stage
- Treated with surgery, chemotherapy, and radiation therapy
Treatment of Thyroid Cancers
- Diagnosis by fine needle aspiration (biopsy)
- Thyroid surgery (usually total thyroidectomy)
- Thyroid hormone replacement pill after surgery
- Papillary cancer may require additional radioactive iodine treatment
- Levothyroxine dose may be adjusted to reduce recurrence risk
- Note: Stop biotin supplements 7 days before lab tests
- Specific treatments:
- Medullary: Surgery and occasional radiation
- Anaplastic: Chemotherapy and radiation
Thyroid Hormone Replacement
- Levothyroxine (T4):
- Generic medication identical to human thyroid hormone
- Synthetically produced
- Body converts T4 to T3 as needed
- Avoid Armour thyroid or similar
- Liothyronine (T3) used only in specific situations:
- Can increase heart palpitation risks
- May thin bones
Survival Rates
- Papillary:
- 5-year survival > 90% when diagnosed before age 65
- Depends on tumor variant and metastasis
- Follicular:
- 10-year survival 80-95%
- Varies by age and disease stage
- Medullary:
- 10-year survival 98% if surgery resolves calcitonin levels
- Approximately 70% survival if calcitonin persists
- Anaplastic:
- Usually fatal within a year
- Focus on patient and family quality of life
Resources
- Never worry alone; visit the clinic if in doubt
- American Cancer Society: Thyroid Cancer Information
- American Thyroid Association: Thyroid Cancer Resources
- Mayo Clinic: www.mayoclinic.com
- National Cancer Institute: Thyroid Treatment Information