From the Guidelines
Management of papillary thyroid carcinoma (PTC) with distant metastasis is primarily based on targeted therapy and radioactive iodine (RAI) treatment.
Treatment Options
- Targeted therapy: Agents with documented efficacy in this setting include lenvatinib, vandetanib, cabozantinib, and pazopanib, sorafenib, sunitinib, axitinib, everolimus 1.
- RAI treatment: Distant metastases are more successfully cured if they take up radioiodine, are of small size located in the lungs (not visible at X-rays) 1.
- BRAF inhibitors: Vemurafenib and dabrafenib can be effective treatment options for DTC harboring the BRAF V600E mutation, which is common in papillary thyroid cancers 1.
Considerations
- Risk stratification: Patients with distant metastases are considered high-risk, with an estimated risk of recurrence of 100% 1.
- Treatment goals: Treatment of distant metastases is often palliative, aiming to prolong survival and improve quality of life 1.
- Side effects: Severe or fatal side effects from kinase inhibitors include bleeding, hypertension, stroke, and liver toxicity; however, most side effects can be managed and are reversible with discontinuation of the drug 1.
From the Research
Management of Papillary Thyroid Carcinoma (PTC) with Distant Metastasis
The management of PTC with distant metastasis involves several factors, including:
- Radioactive iodine (RAI) therapy, which has been the mainstay of treatment for PTC patients with distant metastasis (DM) 2
- Tyrosine kinase inhibitors (TKIs), which were introduced for the treatment of RAI refractory metastatic thyroid carcinoma several years ago 2
- Surgical non-curability, which is an independent risk factor for disease-related death in patients with lung metastasis 2
- Local operative control of PTC, which is important even in patients with distant metastases, particularly when the distant metastases appear to be slow-growing 3
Risk Factors Associated with Disease-Specific Mortality
Several risk factors are associated with disease-specific mortality in PTC patients with distant metastases, including:
- Older age (≥55 years) 2, 4
- Male sex 5, 6
- Distant metastases involving sites other than the lung 2, 3, 6
- Distant metastases diameter ≥ 2 cm 3
- Presence of large nodal metastases (≥ 3 cm) 3
- Primary neoplasm with poorly differentiated components 3
- Radioiodine refractory disease 5
- Metastasis at multiple sites 5, 6
- Brain metastasis 6
Treatment Modalities
Treatment modalities for PTC patients with distant metastases include:
- RAI therapy 2
- TKIs 2
- Surgical resection of the primary tumor and metastatic lesions 3
- Extended resection of the involved organs 3
- Aggressive therapies for recurrent lesions and metastases 4
Survival Rates
Survival rates for PTC patients with distant metastases vary depending on several factors, including:
- Cause-specific survival rates at 10,15, and 20 years after initial surgery: 68.2%, 63.6%, and 61.1%, respectively 2
- Overall survival (OS) rates at 10,15, and 20 years: 97%, 95%, and 90%, respectively 4
- Disease-specific survival (DSS) rates at 5 and 10 years: 65% and 45%, respectively 3
- Median OS in patients with metastases to the brain: 5 months, liver: 6 months, lung: 10 months, and bone: 23 months 6