Treatment of Papillary Thyroid Cancer
The recommended treatment for papillary thyroid cancer is total or near-total thyroidectomy followed by radioactive iodine ablation, except for very low-risk cases with tumors <1 cm without high-risk features. 1
Initial Surgical Management
Surgical Approach
- Total or near-total thyroidectomy is indicated when:
- Diagnosis is made before surgery and nodule is ≥1 cm
- Any size tumor with metastatic disease, multifocal disease, or familial thyroid cancer 1
- Less extensive procedures may be acceptable only for:
- Unifocal tumors <1 cm (T1)
- Intrathyroidal location
- Favorable histology (classical papillary or follicular variant)
- No extrathyroidal extension
- No lymph node metastases 1
Lymph Node Management
- Preoperative neck ultrasound is essential to assess lymph node status 1, 2
- Compartment-oriented microdissection of lymph nodes should be performed for:
- Preoperatively suspected lymph node metastases
- Intraoperatively proven lymph node metastases 1
- Prophylactic central node dissection remains controversial:
- Does not clearly improve recurrence or mortality rates
- Helps with accurate staging to guide subsequent treatment 1
Post-Surgical Radioactive Iodine (RAI) Ablation
Indications
- Recommended for all patients except very low-risk cases 1
- Very low-risk patients (no RAI needed):
- Unifocal T1 tumors <1 cm
- Favorable histology
- No extrathyroidal extension
- No lymph node metastases 1
RAI Administration
- Requires adequate TSH stimulation 1
- Preferred method: Recombinant human TSH (rhTSH) administration while patient remains on levothyroxine therapy 1
- Effective dose options:
- 1850 MBq (50 mCi) is equally effective as 3700 MBq (100 mCi) when prepared with rhTSH, even with lymph node metastases 1
Risk Stratification and Follow-up
Risk Categories
- Based on tumor parameters (TNM staging and histology) and clinical features 1, 2
- Determines intensity of follow-up and degree of TSH suppression 2
TSH Suppression Therapy
- All patients require levothyroxine therapy post-surgery 1, 2
- TSH suppression levels should be tailored to risk:
- High-risk: <0.1 μIU/mL
- Intermediate-risk: 0.1-0.5 μIU/mL
- Low-risk: 0.5-2 μIU/mL (low-normal range) 2
Follow-up Protocol
Standard Follow-up
- 2-3 months post-treatment: Thyroid function tests to check adequacy of levothyroxine therapy 1
- 6-12 months: Assessment to determine disease status 1, 2
- Physical examination
- Neck ultrasound
- Serum thyroglobulin (Tg) measurement
- Annual follow-up if disease-free 2, 3
Advanced or Recurrent Disease Management
- For locally recurrent or metastatic, progressive, radioactive iodine-refractory disease:
- Lenvatinib is FDA-approved 4
- For recurrent locoregional cervical lymph node disease:
- Compartmental lymph node dissection
- Additional radioactive iodine treatment 5
Important Considerations
- Surgical complications (laryngeal nerve palsy, hypoparathyroidism) are rare (<1-2%) when performed by experienced surgeons 1
- RAI therapy is generally well-tolerated with few long-term adverse effects 6
- Serum thyroglobulin is an important tumor marker for follow-up, but requires TSH stimulation for maximum sensitivity 3
- Neck ultrasound has largely replaced routine whole-body radioactive iodine scans in postoperative follow-up 5
By following this treatment algorithm, most patients with papillary thyroid cancer have an excellent prognosis, with 80-90% 10-year survival rates 6.