Guidelines Summary
Guidelines Contributor: Kemp M Anderson Medical University of South Carolina College of Medicine
The following organizations have released guidelines for the diagnosis and/or management of thyroid cancer:
-
National Comprehensive Cancer Network (NCCN) [25]
-
American Association of Clinical Endocrinologists/Associazione Medici Endocrinologi/European Thyroid Association (AACE/AME/ETA [26] (diagnosis only)
Diagnosis
All the guidelines advocate ultrasound evaluation of thyroid nodules along with measurement of serum thyroid-stimulating hormone (TSH) levels to determine whether a fine needle aspiration biopsy (FNAB) is indicated. A routine measurement of serum thyroglobulin (Tg) for the initial evaluation of thyroid nodules is not recommended because Tg levels are elevated in most benign thyroid conditions. [23, 25, 26]
Although all the guidelines recommend FNAB as the procedure of choice in the evaluation of solid thyroid nodules, there is variance in the size of the nodule as an indication for FNAB, as follows [23, 25, 26] :
-
>0.5 cm in diameter (ATA) [23]
-
>1 cm, in the absence of suspicious sonographic features (AACE/AME/ETA) [26]
-
>1 cm if suspicious sonographic features are present; >1.5 cm if no suspicious sonographic features are present (NCCN) [25]
AACE/AME/ETA and NCCN suggest a serum calcitonin assay as an optional test, [25, 26] but the ATA guidelines make no recommendation on the routine measurement of serum calcitonin because of insufficient evidence. [23] All three guidelines recommend radionuclide imaging in patients with a low TSH level. [23, 25, 26]
The ATA guidelines also include the following recommendations regarding diagnosis and staging of ATC [24] :
-
Once the diagnosis of ATC is considered, expeditious assessment of BRAFV600E mutation should be performed by immunohistochemistry (IHC) and confirmed/assessed by molecular testing.
-
Molecular profiling should be performed at the time of ATC diagnosis to inform decisions about targeted therapies.
-
Initial radiological tumor staging should include cross-sectional imaging—in particular, CT with contrast (or MRI) of the neck, chest, abdomen, and pelvis and, if available, FDG PET/CT. Contrast-enhanced imaging of the brain (MRI preferred) should also be performed, if clinically indicated.
-
Evaluation of the vocal cords should be performed in every patient with ATC at initial presentation, and subsequently as indicated by changing symptoms.
Treatment
No curative treatment currently exists for ATC. The majority of patients present with unresectable or metastatic disease. NCCN guidelines recommend attempting total thyroidectomy in patients with resectable disease. [25]
The ATA guidelines strongly recommend surgical resection for patients with confined (stage IVA/IVB) ATC in whom R0/R1 resection is anticipated. Radical resection (eg, laryngectomy, tracheal resections, esophageal resections, major vascular or mediastinal resections) is generally not recommended given the poor prognosis of ATC and should be considered only very selectively after thorough discussion by the multidisciplinary team.
If a primary tumor is deemed unresectable, ATA guidelines advise that in carefully selected patients, neoadjuvant therapy (eg, full or partial course external beam radiotherapy, chemotherapy, or chemoradiotherapy) may permit delayed primary resection. [24] NCCN guidelines recommend considering molecularly targeted neoadjuvant therapy for borderline resectable disease when safe to do so. Targeted regimens for neoadjuvant therapy include the following [25] :
-
BRAF V600E mutations - Dabrafenib/trametinib
-
RET-fusion–positive tumors - Selpercatinib or pralsetinib
-
NTRK gene fusion–positive tumors - Larotrectinib or entrectinib
Both the NCCN and ATA guidelines recommend adjuvant radiation therapy, chemotherapy, or both. [24, 25] ATA recommendations for adjuvant therapy include the following [24] :
-
After R0/R1 resection, patients with good performance status (PS) and no evidence of metastatic disease who wish an aggressive approach should be offered standard fractionation intensity-modulated radiation therapy (IMRT) with concurrent systemic therapy.
-
Patients who have undergone R2 resection or have unresectable but nonmetastatic disease with good PS and who wish an aggressive approach should be offered standard fractionation IMRT with systemic therapy. In BRAF V600E–mutated ATC, combined BRAF/MEK inhibitors can be considered.
-
For patients treated with definitive-intention radiation therapy, cytotoxic chemotherapy involving a taxane, with or without an anthracycline or a platin, is recommended.
-
Algorithm for the management of a solitary thyroid nodule. FNAB = fine needle aspiration biopsy; US = ultrasonography.
