Management of differentiated thyroid cancer
Dr. Leung Tak Lun Canice
North District Hospital
Differentiated thyroid cancer
• Derived from follicular cells– Papillary carcinoma– Follicular carcinoma– Mixed papillary follicular– Follicular variant of papillary carcinoma
• 85% of all thyroid cancers» Udelsman et al. Lancet Oncol. 2005 Jul;6(7):529-31.
Prognostic scoring system
• AGES (Age, Grade, Extent, Size)
• AMES (Age, Metastasis, Extent, Size)
• MACIS (Metastasis, Age, Completeness of resection, Invasion and Size)
Case
• F/45
• Filipino
• Right neck lump for 4 months
• USG neck– 3cm nodule in right lobe of thyroid– Small nodules in left lobe– Bilateral LN metastasis
• FNAC confirmed papillary CA
Treatment modality
• Surgery
• Radioactive iodine ablation
• Others– TSH suppression– RT, Chemotherapy
Surgery
• First line treatment
• The extent?– Thyroid lobectomy and isthmusectomy?– Total thyroidectomy?
• Lymph node dissections?
Total thyroidectomy
• Bilateral thyroid cancers are common– 30-80% of papillary thyroid cancer– 23% of follicular tumours
Udelsman et al. Lancet Oncol. 2005 Jul;6(7):529-31.
Total thyroidectomy
• Bilateral thyroid cancers are common– Lobectomy alone
• 5-10% recurrence rate in contralateral lobe• Higher tumour recurrence rate• Higher pulmonary metastasis
Dackiw et al. Surg Clin North Am 2004; 84 817-32
• Higher 20 yrs local recurrence (14% vs 2%) • Higher 20 yrs nodal metastasis (19% vs 6%)
Hay et al. Surgery 1998;124:958-64
• One third of patient with recurrence subsequently died of thyroid cancer
Total thyroidectomy
• Radioactive iodine– Lower dose ablation– Detect recurrence
» Marraferri EL et al. J Clin Endocinol Metab 2001;86:1447-63» Maxon HR et al. J Nucl Med 1992;33:1132-6
Total thyroidectomy
• Thyroglobulin measurement– Monitor for recurrent disease
• Thyroid hormone withdrawal • rhTSH-stmulated
Total thyroidectomy
• Avoid reoperation– Higher morbidity
• Permanent vocal cord paralysis 1-12%• Permanent hypoparathyroidism 0-3.5%
Kim et al. Arch Otolaryngol Head Neck Surg. 2004 Oct;130(10):1214-6.
Lymph node surgery
• Papillary thyroid cancer – 30% -80% have positives node– Only 10% develop clinically significant
disease – Prophylactic modified neck dissections are
not recommended
Lymph node surgery
• Central compartment dissection has similar complication rates
Montesani et al. Ann Ital Chir. 2004 May-Jun;75(3):299-303
• Reoperative central compartment dissection with increased morbidity
Lymph node dissection
• Functional neck dissection– Indicated when there is clinical or radiological
evidence of lateral lymph node metastasis
Radioactive iodine
• Ablation– Aims to destroy residual normal thyroid tissue– Decreases local recurrence and distant metas
tasis Sawka et al. J Clin Endocrinol Metab 89: 3668-3676,2004
– Recommended in • All follicular CA• High risk papillary CA (MACIS 6 or more)
Tx
• TSH suppression
• External beam RT – Controversial– Not indicated in patients with good prognostic
features
Follow-up
• Physical examination
• Serum thyroglobulin measurement
• Radioactive scanning and USG neck when suspicious of recurrence
Case
• Total thyroidectomy with central compartment dissection and bilateral functional neck dissection
Case
• Post-op uneventful
• No vocal cord palsy
• No hypocalcaemia
• D/C on day 4
Summary
• Total thyroidectomy is recommended in all patients
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