What is the treatment for thyroid tumors?

Treatment of Thyroid Tumors

The initial treatment for differentiated thyroid carcinoma (DTC) is total or near-total thyroidectomy followed by radioiodine ablation for high-risk patients, with treatment approach varying based on tumor type, size, and risk factors. 1

Diagnosis and Pre-Treatment Assessment

• Thyroid ultrasound (US) supplemented by fine needle aspiration cytology (FNAC) should be used as first-line diagnostic procedure for detecting and characterizing nodular thyroid disease 1
• FNAC should be performed in any thyroid nodule >1 cm and in those <1 cm if there are suspicious clinical or ultrasonographic features 1
• Serum calcitonin measurement is recommended as part of the diagnostic evaluation of thyroid nodules to detect medullary thyroid cancer 1
• Pre-surgery staging should include careful exploration of the neck by ultrasound to assess lymph node status 1

Treatment by Thyroid Cancer Type

Differentiated Thyroid Cancer (Papillary and Follicular)

• Surgical Management:

  • Total or near-total thyroidectomy is recommended when diagnosis is made before surgery and the nodule is ≥1 cm 1
  • Less extensive procedures (lobectomy) may be accepted for unifocal DTC diagnosed after surgery for benign conditions, if the tumor is small, intrathyroidal, and of favorable histology 1
  • Compartment-oriented lymph node dissection should be performed for clinically evident lymph node metastases 1

• Post-Surgical Treatment:

  • Radioiodine (131I) ablation is indicated in high-risk patients to eliminate remnant thyroid tissue and potential microscopic residual tumor 1
  • Radioiodine is not indicated in low-risk patients (unifocal T1 tumors <1 cm with favorable histology) 1
  • For intermediate-risk patients, the decision for radioiodine ablation must be individualized based on specific risk factors 1
  • Post-surgery thyroid hormone therapy should be initiated for both replacement and TSH suppression, particularly beneficial in high-risk patients 1

• Follow-up Protocol:

  • 2-3 months after initial treatment: Thyroid function tests to check adequacy of LT4 suppressive therapy 1
  • 6-12 months: Physical examination, neck US, and basal and rhTSH-stimulated serum thyroglobulin measurement 1
  • Annual follow-up for disease-free patients with physical examination, basal serum Tg measurement, and neck US 1

Medullary Thyroid Cancer (MTC)

• Pre-Surgical Assessment:

  • Staging work-up including basal serum calcitonin, CEA, calcium, and plasma metanephrines/normetanephrines 1

• Surgical Management:

  • Total thyroidectomy with bilateral prophylactic central lymph-node dissection for patients without evidence of lymph node metastases 1
  • Lateral neck dissection for patients with positive preoperative imaging 1

• Post-Surgical Management:

  • Replacement thyroxine treatment to maintain serum TSH within normal range 1
  • Regular monitoring of serum markers (calcitonin and CEA) 1
  • For advanced/metastatic MTC, targeted therapies such as vandetanib (FDA and EMA approved) may be considered 1

Poorly Differentiated Thyroid Carcinoma (PDTC)

• Total thyroidectomy is the initial treatment 1
• Lymph node dissection should be considered as regional nodal metastases are present in over 50% of PDTC patients at diagnosis 1
• TSH suppressive therapy with LT4 should be initiated immediately following surgery 1
• PDTC responds poorly to radioactive iodine compared to well-differentiated thyroid cancers 1

Treatment of Recurrent or Metastatic Disease

• Recurrent locoregional disease: Combination of surgery and radioiodine therapy, supplemented by external beam radiotherapy if surgery is incomplete or there is lack of RAI uptake 1
• Distant metastases are more successfully treated if they are RAI-avid, small, and located in the lungs 1
• For advanced disease that doesn't respond to conventional therapy, clinical trial participation should be encouraged 1
• Newer targeted therapies including multikinase inhibitors are increasingly used for advanced thyroid cancer 2

Special Considerations

• Risk stratification systems (AJCC, ATA, ETA) should be used to guide treatment decisions 1
• Elderly patients and those with underlying cardiovascular disease require careful dose titration of thyroid hormone therapy due to increased risk of cardiac adverse reactions 3
• Benign colloid cysts of the thyroid can be managed with observation if asymptomatic, or aspiration if symptomatic 4
• For recurrent benign cysts, ethanol ablation or thermal ablation techniques may be considered before resorting to surgery 4

Common Pitfalls to Avoid

• Overtreatment of very low-risk microcarcinomas (<1 cm) with aggressive surgery and radioiodine 1
• Inadequate lymph node assessment before surgery, potentially missing clinically significant nodal disease 1
• Failure to monitor for complications of thyroid hormone suppressive therapy, including bone mineral density loss and cardiac effects 3
• Neglecting long-term surveillance, as recurrences can occur even decades after initial treatment 1