Sipos, Jennifer A.

The NCCN Guidelines for Thyroid Carcinoma address the management of different types of thyroid carcinoma, including papillary, follicular, oncocytic, medullary, and anaplastic carcinoma. The NCCN Thyroid Carcinoma Panel meets at least annually to review comments from reviewers within their institutions, examine relevant new data from publications and abstracts, and reevaluate and update their recommendations. These NCCN Guidelines Insights focus on the panel’s most recent recommendations regarding systemic therapies for thyroid carcinoma as well as the supporting clinical data.

Abstract Background Patients with sporadic or hereditary Medullary Thyroid Carcinoma (MTC) often undergo total thyroidectomy and lymph node dissection, with postoperative surveillance relying on serum calcitonin levels and ultrasound examinations. According to American Thyroid Association (ATA) guidelines, detectable levels of serum calcitonin and Carcinoembryonic Antigen (CEA) post-thyroidectomy suggest potential disease persistence or recurrence, necessitating frequent monitoring for early detection. This study sought to reassess the role of postoperative calcitonin levels in identifying possible tumor recurrence. Methods A retrospective analysis was conducted using Siemens Atellica to test calcitonin levels in 562 samples collected between 09/27/2022 and 08/11/2023, at least 3 months post-total thyroidectomy. Imaging studies performed within 6 months of the calcitonin assessment were also reviewed. Sample pools with calcitonin concentrations near 3.00 and 5.00 pg/mL were utilized to determine the limit of quantification (LoQ). CEA results were included for comparison. Additionally, 16 serum samples were analyzed using the Roche Cobas system at a reference laboratory. Results Precision analysis around 3.00 and 5.00 pg/mL revealed coefficients of variation (CVs) of 16.49% and 8.87%, respectively. Comparison of calcitonin levels between Siemens Atellica and Roche Cobas systems demonstrated consistent levels < 5.00 pg/mL in 15 out of 16 samples, indicating alignment and reliability between the platforms. A calcitonin cutoff of 1.89 pg/mL yielded 43% sensitivity and 67% specificity, while a cutoff of 5.00 pg/mL resulted in 0% sensitivity and 100% specificity. Conclusions Our findings suggest that a 5 pg/mL calcitonin cutoff on the Siemens Atellica platform may be suitable for identifying tumor persistence or recurrence in post-thyroidectomy patients within our institution. However, individual laboratories should establish their LoQ criteria when interpreting calcitonin levels for postoperative monitoring of tumor recurrence.

Differentiated thyroid carcinomas is associated with an excellent prognosis. The treatment of choice for differentiated thyroid carcinoma is surgery, followed by radioactive iodine ablation (iodine-131) in select patients and thyroxine therapy in most patients. Surgery is also the main treatment for medullary thyroid carcinoma, and kinase inhibitors may be appropriate for select patients with recurrent or persistent disease that is not resectable. Anaplastic thyroid carcinoma is almost uniformly lethal, and iodine-131 imaging and radioactive iodine cannot be used. When systemic therapy is indicated, targeted therapy options are preferred. This article describes NCCN recommendations regarding management of medullary thyroid carcinoma and anaplastic thyroid carcinoma, and surgical management of differentiated thyroid carcinoma (papillary, follicular, Hürthle cell carcinoma).

Abstract BACKGROUND The objective of this study is the validation and proof of clinical relevance of a novel electrochemiluminescence immunoassay (ECLIA) for the determination of serum calcitonin (CT) in patients with medullary thyroid carcinoma (MTC) and in different diseases of the thyroid and of calcium homeostasis. METHODS This was a multicenter prospective study on basal serum CT concentrations performed in 9 US and European referral institutions. In addition, stimulated CT concentrations were measured in 50 healthy volunteers after intravenous calcium administration (2.5 mg/kg bodyweight). RESULTS In total, 1929 patients and healthy controls were included. Limits of blank, detection, and quantification for the ECLIA were 0.3, 0.5, and 1 ng/L, respectively. Highest intra- and interassay coefficients of variation were 7.4% (CT concentration, 0.8 ng/L) and 7.0% (1.1 ng/L), respectively. Medians (interval) of serum CT concentrations in 783 healthy controls were 0.8 ng/L (<0.5–12.7) and 3 ng/L (<0.5–18) for females and males, respectively (97.5th percentile, 6.8 and 11.6 ng/L, respectively). Diagnostic sensitivity and specificity were 100%/97.1% and 96.2%/96.4%, for female/males, respectively. Patients (male/female) with primary hyperparathyroidism, renal failure, and neuroendocrine tumors showed CT concentrations >97.5th percentile in 33%/4.7%, 18.5%/10%, and 8.3%/12%, females/males, respectively. Peak serum CT concentrations were reached 2 min after calcium administration (161.7 and 111.8 ng/L in males and females, respectively; P < 0.001). CONCLUSIONS Excellent analytical performance, low interindividual variability, and low impact of confounders for increased CT concentrations in non-MTC patients indicate that the investigated assay has appropriate clinical utility. Calcium-stimulated CT results suggest good test applicability owing to low interindividual variability.