From the Guidelines
Treatment Options for Metastatic Papillary Thyroid Carcinoma (PTC)
The primary treatment approach for metastatic PTC involves systemic therapy with targeted agents for patients with advanced or metastatic disease that is not amenable to surgery or radioactive iodine therapy 1.
First-Line Treatment
The recommended first-line treatment options include sorafenib, a multikinase inhibitor, at a dose of 400 mg orally twice daily, and lenvatinib, another multikinase inhibitor, at a dose of 24 mg orally once daily 1.
Alternative Options
In patients who have progressed on or are intolerant to these agents, other options such as cabozantinib or vandetanib may be considered 1. It is essential to monitor patients closely for adverse effects, such as bleeding, hypertension, stroke, and liver toxicity, and adjust the treatment plan accordingly 1.
BRAF V600E-Mutated Metastatic PTC
For patients with BRAF V600E-mutated metastatic PTC, vemurafenib and dabrafenib are effective treatment options, with response rates of 38.5% and 29%, respectively 1. Dabrafenib may also sensitize tumors to radioactive iodine therapy, with 60% of patients showing increased radioiodine uptake 1.
Key Considerations
- Treatment should be individualized and guided by a multidisciplinary team of healthcare professionals, including endocrinologists, medical oncologists, and surgeons.
- Genomic testing is crucial to identify actionable mutations, such as BRAF V600E, to inform treatment decisions and eligibility for clinical trials 1.
- Emerging data suggest that anaplastic lymphoma kinase (ALK) inhibitors may be effective in patients with papillary carcinoma who have ALK gene fusion 1.
From the FDA Drug Label
1.3 Differentiated Thyroid Carcinoma Sorafenib tablets are indicated for the treatment of patients with locally recurrent or metastatic, progressive, differentiated thyroid carcinoma (DTC) that is refractory to radioactive iodine treatment.
1 INDICATIONS AND USAGE
1.1 Differentiated Thyroid Cancer LENVIMA is indicated for the treatment of adult patients with locally recurrent or metastatic, progressive, radioactive iodine-refractory differentiated thyroid cancer (DTC).
HIGHLIGHTS OF PRESCRIBING INFORMATION CABOMETYX is a kinase inhibitor indicated for the treatment of patients with advanced renal cell carcinoma (RCC) ... adult and pediatric patients 12 years of age and older with locally advanced or metastatic differentiated thyroid cancer (DTC) that has progressed following prior VEGFR-targeted therapy and who are radioactive iodine-refractory or ineligible (1.3)
The treatment options for metastatic papillary thyroid carcinoma (PTC) include:
- Sorafenib: indicated for the treatment of patients with locally recurrent or metastatic, progressive, differentiated thyroid carcinoma (DTC) that is refractory to radioactive iodine treatment 2
- Lenvatinib: indicated for the treatment of adult patients with locally recurrent or metastatic, progressive, radioactive iodine-refractory differentiated thyroid cancer (DTC) 3
- Cabozantinib: indicated for the treatment of adult and pediatric patients 12 years of age and older with locally advanced or metastatic differentiated thyroid cancer (DTC) that has progressed following prior VEGFR-targeted therapy and who are radioactive iodine-refractory or ineligible 4
From the Research
Treatment Options for Metastatic Papillary Thyroid Carcinoma (PTC)
- Initial treatment of papillary thyroid cancer involves resection of the primary tumor, with resection of regional lymph nodes if involved with metastatic disease 5
- Postoperative adjuvant therapy consists of radioactive iodine ablation for most patients, followed by thyroid-stimulating hormone (TSH) suppression with thyroxine 5
- For patients with distant metastatic disease, treatment options are limited and often ineffective, with a poor overall prognosis and outcome 6
- A multimodal, comprehensive approach to managing complex patients is essential to optimize both the sequence and therapeutic approach to treatment 6
- Directed techniques can target metastatic disease, including bisphosphonates, radiofrequency ablation, or radiotherapy 7
- Systemic therapies such as tyrosine kinase inhibitors show great promise, although such treatment must be individualized 7
- Radioiodine (RAI) therapy remains the gold-standard approach for distant metastatic differentiated thyroid cancer (TC) 8
- Emerging therapies include redifferentiation agents, antiangiogenic agents, and multi-tyrosine kinase inhibitors for patients whose tumor has become radioactive iodine resistant 5
- Molecular techniques are increasingly being used to risk stratify and guide therapeutic decisions, with advances in the treatment of local disease through surgery or radioiodine 7
- Early identification of molecular markers in primary tumours may help to predict RAI therapy avidity, the response of metastatic lesions, and to select the patients that may benefit the most from other systemic therapies 8
Multidisciplinary Approach to Treatment
- A multidisciplinary team comprising endocrinologists, nuclear medicine physicians, radiation safety specialists, and the nursing department can develop a radiation mitigation strategy to ensure patient and staff safety during RAI therapy 9
- The proposed standardized approach includes thorough monitoring of radiation levels in the workplace, providing additional protective equipment for workers, and implementing strict guidelines for safely disposing of radioactive waste 9
- This approach requires enhanced training, role preparation, and practice, as well as estimation of the safe exposure time for caregivers based on dosimetry 9
Challenges and Future Perspectives
- High-activity radioactive iodine (RAI) therapy for metastatic thyroid cancer (TC) requires isolation to minimize radiation exposure to third parties, posing challenges for patients needing hands-on care 9
- Future therapies will target treating radioiodine refractory disease, with ongoing research into molecular techniques and emerging therapies 5, 7