The Japan Associations of Endocrine Surgeons (JAES) have developed and published updated clinical practice guidelines on the management of thyroid tumors.
Papillary Thyroid Carcinoma
The management of papillary thyroid carcinoma (PTC) should be based on risk classification: very low-risk, low-risk, intermediate-risk, and high-risk.
Total thyroidectomy is recommended for high-risk PTC but not for very low- and low-risk PTC (T1N0M0). As for intermediate-risk PTC, the extent of thyroidectomy chosen should be based on prognosis and patient background characteristics.
Prophylactic central lymph node dissection is recommended in the surgical treatment of PTC. For low-risk PTC, prophylactic lateral lymph node dissection is not recommended. As for intermediate and high-risk PTC, the decision to perform prophylactic lateral node dissection should be based on the patient’s prognostic factors, background, and decision.
Nonsurgical active surveillance is recommended for very low-risk PTC in patients without evidence of metastasis or extension (T1aN0M0) after an adequate explanation of disease condition and the benefits and risks of management are provided to the patient.
Follicular Thyroid Carcinoma
Total thyroidectomy and radioactive iodine (RAI) therapy are recommended for widely invasive follicular thyroid carcinoma (FTC) with distant metastasis (M1). Completion total thyroidectomy is recommended for widely invasive FTC without distant metastasis (M0) diagnosed after lobectomy.
Completion total thyroidectomy is not uniformly recommended for M0 minimally invasive FTC after lobectomy.
Medullary Thyroid Carcinoma
All patients with medullary thyroid carcinoma (MTC) should undergo RET gene mutation analysis.
Prophylactic total thyroidectomy is not uniformly recommended for carriers of RET mutations who have not developed MTC.
Although the lesion is limited to one lobe, total thyroidectomy is recommended for hereditary MTC since the bilateral C cells may become cancerous.
Prophylactic central node dissection is also recommended for MTC.
Poorly Differentiated Carcinoma
Total thyroidectomy, prophylactic lymph node dissection, and RAI therapy are recommended for poorly differentiated carcinoma.
Anaplastic Thyroid Carcinoma
After curative surgery for anaplastic thyroid carcinoma (ATC) is performed, adjuvant therapies are recommended.
Multidisciplinary treatment is recommended for unresectable ATC.
For a recurrent lesion diagnosed as ATC in a patient with differentiated thyroid carcinoma (DTC), a treatment strategy for ATC is recommended.
Palliative care is recommended for ATC.
Postoperative adjuvant RAI therapy is recommended for high-risk PTC without distant metastasis (M0). Postoperative ablative RAI therapy is considered for intermediate-risk PTC after the patient’s prognostic factors are considered. Postoperative ablative RAI therapy is not recommended for low-risk PTC. Postoperative ablative or adjuvant RAI therapy is recommended for widely invasive FTC without distant metastasis (M0). Postoperative ablative RAI therapy is not recommended for minimally invasive FTC.
Iodine restriction is recommended for improving the accumulation of RAI to the normal remnant thyroid or malignant thyroid tissue.
Appropriate doses of RAI for RAI therapy are as follows:
1.1 GBq (30 mCi) for ablative RAI therapy
3.7-5.6 GBq (100-150 mCi) for adjuvant RAI therapy
3.7-7.4 GBq (100-200 mCi) for treatment
The decision for RAI therapy to treat recurrent differentiated thyroid carcinoma should be made after disease progression and location, number, and size of recurrent lesions are thoroughly considered. RAI therapy is strongly recommended for lung metastasis and bone metastasis. It is weakly recommended for either local recurrence or lymph node metastasis that is inoperable but requires therapy. RAI therapy is not recommended for brain metastasis, for metastasis to organs other than those already mentioned, or for patients without apparent recurrence but with high thyroglobulin levels.
Recombinant human thyroid-stimulating hormone (rhTSH) to increase thyrotropin levels at the time of RAI administration is recommended as a substitute for levothyroxine withdrawal before I-131 whole-body scan (WBS), serum thyroglobulin test, and ablation.
Extra beam radiotherapy is recommended in patients with symptoms due to advanced or recurrent thyroid carcinoma, since salvage surgery, RAI therapy, and molecular target drugs are not indicated.
Advanced Differentiated Carcinoma
In patients with preoperative nerve paralysis, resection of the invaded recurrent laryngeal nerve is recommended. Preservation of the nerve is recommended in patients without preoperative nerve paralysis.
Nerve reconstruction is recommended at the same time as the nerve resection.
Resection of the invaded tracheal wall is recommended and should be tailored based on disease stage, extension of tumor spread, risk of surgical complications, anticipated postoperative quality of life, prognosis, and skill of the treatment team.
Postoperative Therapy (Including for Recurrence and Metastasis)
For intermediate-risk PTC, the decision for TSH suppression therapy should be based on intraoperative and pathological findings. TSH suppression therapy is recommended for high-risk PTC and widely invasive FTC.
Cytotoxic chemotherapy is not recommended for advanced or recurrent DTC.
Alternative medicine is not recommended because of its unproven effectiveness in antitumor activity or survival benefit in patients with thyroid cancer.
Molecular Target Medicine Therapy
Molecular target medicine is recommended for progressive DTC that is refractory to RAI therapy.
Molecular target medicine is recommended for progressing advanced or recurrent MTC.
Molecular target medicine (lenvatinib) is also recommended for unresectable advanced or recurrent ATC.
For more information, please go to Thyroid Cancer.
For more Clinical Practice Guidelines, please go to Guidelines.
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Cite this: Thyroid Carcinoma Clinical Practice Guidelines (2020) - Medscape - May 12, 2020.