Significance of Thyroglobulin Autoantibodies in Patients With Thyroid Cancer Treated With Lenvatinib.

Context: Serum thyroglobulin (Tg) is a highly sensitive and specific tumor marker, employed in post-operative management of patients with differentiated thyroid carcinomas. Tumor shrinkage of radioiodine-refractory thyroid cancer (RAIR-DTC) treated with multitarget kinase inhibitors as lenvatinib, expressed according to the Response Evaluation Criteria in Solid Tumors (RECIST), is also associated with a drastic reduction of Tg levels. However, interference caused by circulating thyroglobulin autoantibodies (TgAb) represents the main limitation in the clinical use of Tg. Objective: To evaluate if in RAIR-DTC TgAb could be considered a surrogate marker of Tg in monitoring response to treatment with lenvatinib. Design: We retrospectively evaluated patients who had started lenvatinib and correlated serum Tg and TgAb with the radiological response across visits. Setting: University of Pisa, Italy. Patients: We selected 9/97 RAIR-DTC patients with detectable TgAb. Intervention: None. Main Outcome Measures: None. Results: Tg values correlated neither with TgAb title nor with radiological response across visits. Greater decreases in TgAb titer correlated with favorable radiological response to lenvatinib after 1 month (Spearman's correlation = 0.74, P = .021) and 6 months (correlation = 0.61, P = .079). According to RECIST, patients with partial response showed a ∼10-fold greater decrease in TgAb compared to those with stable disease at 1 month (median TgAb decrease: -142 vs -14 IU/mL, P = .01) and those with progressive disease at 6 months (median TgAb decrease: -264 vs-24 IU/mL, P = .04). Conclusion: TgAb evaluation may represent a reliable surrogate marker for Tg trend in evaluating response of RAIR-DTC to treatment with lenvatinib. A multicentric study would be useful to confirm our results.

Cytological and Ultrasound Features of Thyroid Nodules Correlate With Histotypes and Variants of Thyroid Carcinoma.

CONTEXT: Prognosis is excellent for papillary thyroid carcinoma (PTC), noninvasive follicular thyroid neoplasia with papillary-like nuclear features (NIFT-P), and follicular thyroid carcinoma (FTC) but is poor for poorly differentiated thyroid carcinoma (PDTC) and anaplastic thyroid carcinoma (ATC). Among PTCs, the prognosis is more favorable for follicular (FV-PTC) and classic (CV-PTC) than for tall cell (TCV-PTC), and solid (SV-PTC) variants. OBJECTIVE: To associate histotypes and variants of thyroid carcinoma with ultrasound and cytological features. METHODS: Histology of 1018 benign tumors and 514 PTC (249 CV, 167 FV, 49 TC, 34 SV, and 15 other variants), 52 NIFT-P, 50 FTC, 11 PDTC, and 3 ATC was correlated with fine-needle aspiration biopsy categories (Italian classification: TIR1, TIR2, TIR3A, TIR3B, TIR4, and TIR5) and ultrasound features at the Endocrinology Unit, University Hospital of Pisa. In total, 1117 patients with thyroid nodule(s) who underwent thyroidectomy were included. RESULTS: Of PTC, 36.3% had indeterminate cytology (TIR3A or TIR3B), 56.6% were suspicious for malignancy or malignant (TIR4 or TIR5); 84.0% FTC and 69.3% NIFT-P were TIR3A or TIR3B; 72.5% FV-PTC and 73.6% SV-PTC were TIR3A or TIR3B; 79.9% CV-PTC and 95.9% TCV-PTC were TIR4 or TIR5. The association of a hypoechoic pattern, irregular margins, and no microcalcifications was more frequent in TCV-PTC than in CV-PTC (P = .02, positive predictive value = 38.9%; negative predictive value = 85.5%). CONCLUSION: At cytology, most FTC, NIFT-P, FV-PTC, and SV-PTC were indeterminate, most CV-PTC and TCV-PTC were suspicious for malignancy or malignant. Ultrasound can be helpful in ruling out TCV-PTC.

Thyroid autoimmunity, thyroglobulin autoantibodies, and thyroid cancer prognosis.

The relevance of thyroid autoimmunity to the prognosis of papillary thyroid carcinoma is still unsettled. We decided to investigate the impact of thyroid autoimmunity on the prognosis of papillary thyroid carcinoma and the handling of TgAbs. We evaluated the clinical course of a large group of patients according to the presence (PTC-LT) or absence (PTC) of lymphocytic thyroiditis at histology. We studied 194 consecutive patients with a diagnosis of PTC and treated them with total thyroidectomy plus ¹³¹I ablation between 2007 and 2009. Median follow-up (with 25th-75th percentiles) was 84.0 (56.4-118.0) months. The remission criteria were: basal Tg < 0.2 ng/mL (or stimulated Tg: < 1), TgAbs < 8 IU/mL (otherwise 'decreasing TgAb trend', a decline of ≥20% in sequential TgAb measurements) and unremarkable imaging. PTC-LT and PTC patients had comparable treatment.TgAbs were detectable in 72.5% of PTC-LT and 16.5% of PTC patients. Time to remission was longer in the detectable than in the undetectable TgAb cohort (28.5 vs· 7.5 months (median); HR: 0.54, CI: 0.35-0.83, P = 0.005). When comparing PTC-LT to PTC patients, the difference was maintained in the detectable TgAb (29.3 vs 13.0 months; HR: 0.38, CI: 0.18-0.80; P = 0.01) but not in the undetectable TgAb cohort (7.7 vs 7.3 months; HR: 0.90, CI: 0.55-1.47; P = 0.68). Using the decreasing TgAb trend, the influence of detectable TgAbs on time to remission was abolished. Thyroid autoimmunity does not influence the prognosis of papillary thyroid carcinoma. A decreasing TgAb trend seems an appropriate criterion to establish the remission of papillary thyroid carcinoma.

Steroid treatment in the management of destructive thyrotoxicosis induced by PD1 blockade.

Objective: Destructive thyroiditis is the most common endocrine immune-related adverse event (iRAEs) in patients treated with anti-PD1/PD-L1 agents. Given its self-limited course, current guidelines recommend no treatment for this iRAE. Nevertheless, in patients with enlarged thyroid volume and a poor performance status, thyrotoxicosis may be particularly severe and harmful. The aim of the study is to evaluate if steroid treatment might be useful in improving thyrotoxicosis in subjects with a poor performance status. Methods: We conducted a retrospective study, comparing the course of thyrotoxicosis of four patients treated with oral prednisone at the dosage of 25 mg/day (tapered to discontinuation in 3 weeks) and an enlarged thyroid volume to that of eight patients with similar thyroid volume who were left untreated. Results: The levels of thyroid hormones were lower in subjects treated compared to those untreated at time of 7, 14, 21, 28, 35, 42, 60 and 90 days (P < 0.05 at each time). The time to remission of thyrotoxicosis was 24 days in patients treated with steroids and 120 days in untreated patients (P < 0.001). At 6 months, the rate of evolution to hypothyroidism was similar in the two groups (4/4 in the steroid group vs 7/8 in the untreated group, P = 0.74) and no difference was found in tumor progression (P = 0.89). Conclusions: Our preliminary data suggest that in patients with a poor performance status experiencing a severe destructive thyrotoxicosis induced by PD-1 blockade, a short period of administration of oral prednisone is effective in obtaining a quick reduction of the levels of thyroid hormones.

Subacute Thyroiditis During the SARS-CoV-2 Pandemic.

CONTEXT: Acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been related to subacute thyroiditis (SAT). OBJECTIVE: We compared SAT cases during the SARS-CoV-2 pandemic to those observed in the previous years. METHODS: A cross-sectional, retrospective study was conducted at the Endocrinology Unit of University Hospital of Pisa, Italy. We included all patients observed from January 2016 to December 2020 because of an untreated SAT, who had developed the disease within 15 days prior to the visit. SAT cases from 2016 to 2019 (N = 152) are referred to as pre-SARS-CoV-2, while 2020 SAT patients are classified as pos-SARS-CoV-2 (N = 18) or neg-SARS-CoV-2 (N = 28), according to positive or negative SARS-CoV-2 testing performed up to 45 days from SAT onset. RESULTS: While during 2016-2019, most SAT cases were observed in the third quarter, in 2020, 2 peaks were seen, superimposable to the SARS-CoV-2 outbreaks in the second and the fourth quarters. In the second and fourth quarters of 2020, we observed higher levels of free thyroxine (FT4), C-reactive protein (CRP), and thyroglobulin (Tg) compared with the same quarters of the years 2016-2019. Pos-SARS-CoV-2 patients had higher FT4 (28.4 vs 24.1 nmol/L), CRP (8.5 vs 3.6 mg/L), and Tg (155 vs 60 µg/L) (P < 0.05 for all) and more frequently had hypothyroidism (13/15 vs 30/152 at 3 months) (P < 0.001) than pre-SARS-CoV-2 patients. Neg-SARS-CoV-2 patients showed a clinical picture intermediate between the other 2 groups. CONCLUSION: The SARS-CoV-2 pandemic has caused a shift in the annual timing and severity of SAT cases.

Management of Thyrotoxicosis Induced by PD1 or PD-L1 Blockade.

CONTEXT: Thyrotoxicosis is a common immune-related adverse event in patients treated with programmed cell death protein-1 (PD1) or programmed cell death protein ligand-1 (PD-L1) blockade. A detailed endocrinological assessment, including thyroid ultrasound and scintigraphy, is lacking, as are data on response to treatment and follow-up. OBJECTIVE: The aim of this study was to better characterize the thyrotoxicosis secondary to immune checkpoint inhibitors, gaining insights into pathogenesis and treatment. METHODS: We conducted a retrospective study of 20 consecutive patients who had normal thyroid function before starting immunotherapy and then experienced thyrotoxicosis on PD1 or PD-L1 blockade. Clinical assessment was combined with thyroid ultrasound, 99mtechnecium scintiscan, and longitudinal thyroid function tests. RESULTS: Five patients had normal or increased scintigraphic uptake (Sci+), no serum antibodies against the thyrotropin receptor, and remained hyperthyroid throughout follow-up. The other 15 patients had no scintigraphic uptake (Sci-) and experienced destructive thyrotoxicosis followed by hypothyroidism (N = 9) or euthyroidism (N = 6). Hypothyroidism was more readily seen in those with normal thyroid volume than in those with goiter (P = .04). Among Sci- individuals, a larger thyroid volume was associated with a longer time to remission (P < .05). Methimazole (MMI) was effective only in Sci+ individuals (P < .05). CONCLUSION: Administration of PD1- or PD-L1-blocking antibodies may induce 2 different forms of thyrotoxicosis that appear similar in clinical severity at onset: a type 1 characterized by persistent hyperthyroidism that requires treatment with MMI, and a type 2, characterized by destructive and transient thyrotoxicosis that evolves to hypothyroidism or euthyroidism. Thyroid scintigraphy and ultrasound help in differentiating and managing these 2 forms of iatrogenic thyrotoxicosis.

Is Subacute Thyroiditis an Underestimated Manifestation of SARS-CoV-2 Infection? Insights From a Case Series.

CONTEXT: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected more than 18 million people worldwide and the pandemic is still spreading. After the first case we reported, we observed 4 additional cases of subacute thyroiditis (SAT) related to SARS-CoV-2 infection. OBJECTIVES: The objective of this work is to describe additional cases of SAT associated with SARS-CoV-2 infection to alert physicians that SAT may be a manifestation of SARS-CoV-2 infection. METHODS: We describe clinical, biochemical, and imaging features of 4 patients with SAT related to SARS-CoV-2 infection. RESULTS: All patients were female (age, 29-46 years). SAT developed 16 to 36 days after the resolution of coronavirus disease 2019 (COVID-19). Neck pain radiated to the jaw and palpitations were the main presenting symptoms and were associated with fever and asthenia. One patient was hospitalized because of atrial fibrillation. Thyroid function tests (available for 3 individuals) were suggestive of destructive thyroiditis, and inflammatory markers were high. At neck ultrasound the thyroid was enlarged, with diffuse and bilateral hypoechoic areas and (in 3 patients) absent vascularization at color Doppler. Symptoms disappeared a few days after commencement of treatment (prednisone in 3 patients and ibuprofen in 1). Six weeks after the onset of SAT, all patients were asymptomatic and inflammatory markers had returned to normal range. Two patients were euthyroid, whereas 2 were diagnosed with subclinical hypothyroidism. CONCLUSIONS: SAT may be an underestimated manifestation of COVID-19. Clinicians should keep in mind the possible occurrence of SAT during and after SARS-CoV-2 infection.

Subacute Thyroiditis After Sars-COV-2 Infection.

CONTEXT: Subacute thyroiditis (SAT) is a thyroid disease of viral or postviral origin. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that began in Wuhan, China, has spread rapidly worldwide and Italy has been severely affected by this outbreak. OBJECTIVES: The objective of this work is to report the first case of SAT related to SARS-CoV-2 infection. METHODS: We describe the clinical, laboratory, and imaging features of an 18-year-old woman who came to our attention for fever, neck pain radiated to the jaw, and palpitations occurring 15 days after a SARS-CoV-2-positive oropharyngeal swab. Coronavirus disease 2019 (COVID-19) had been mild and the patient had completely recovered in a few days. RESULTS: At physical examination the patient presented with a slightly increased heart rate and a painful and enlarged thyroid on palpation. At laboratory exams free thyroxine and free triiodothyronine were high, thyrotropin undetectable, and inflammatory markers and white blood cell count elevated. Bilateral and diffuse hypoechoic areas were detected at neck ultrasound. One month earlier, thyroid function and imaging both were normal. We diagnosed SAT and the patient started prednisone. Neck pain and fever recovered within 2 days and the remaining symptoms within 1 week. Thyroid function and inflammatory markers normalized in 40 days. CONCLUSIONS: We report the first case of SAT after a SARS-CoV-2 infection. We alert clinicians to additional and unreported clinical manifestations associated with COVID-19.

Clinical heterogeneity of hypophysitis secondary to PD-1/PD-L1 blockade: insights from four cases.

SUMMARY: Programmed cell death protein 1/programmed cell death protein ligand 1 (PD-1/PD-L1) and cytotoxic T-lymphocyte antigen 4/B7 (CTLA-4/B7) pathways are key regulators in T-cell activation and tolerance. Nivolumab, pembrolizumab (PD-1 inhibitors), atezolizumab (PD-L1 inhibitor) and ipilimumab (CTLA-4 inhibitor) are monoclonal antibodies approved for treatment of several advanced cancers. Immune checkpoint inhibitors (ICIs)-related hypophysitis is described more frequently in patients treated with anti-CTLA-4; however, recent studies reported an increasing prevalence of anti-PD-1/PD-L1-induced hypophysitis which also exhibits slightly different clinical features. We report our experience on hypophysitis induced by anti-PD-1/anti-PD-L1 treatment. We present four cases, diagnosed in the past 12 months, of hypophysitis occurring in two patients receiving anti-PD-1, in one patient receiving anti-PD-1 and anti-CTLA-4 combined therapy and in one patient receiving anti-PD-L1. In this case series, timing, clinical presentation and association with other immune-related adverse events appeared to be extremely variable; central hypoadrenalism and hyponatremia were constantly detected although sellar magnetic resonance imaging did not reveal specific signs of pituitary inflammation. These differences highlight the complexity of ICI-related hypophysitis and the existence of different mechanisms of action leading to heterogeneity of clinical presentation in patients receiving immunotherapy. LEARNING POINTS: PD-1/PD-L1 blockade can induce hypophysitis with a different clinical presentation when compared to CTLA-4 blockade. Diagnosis of PD-1/PD-L1 induced hypophysitis is mainly made on clinical grounds and sellar MRI does not show radiological abnormalities. Hyponatremia due to acute secondary adrenal insufficiency is often the principal sign of PD-1/PD-L1-induced hypophysitis and can be masked by other symptoms due to oncologic disease. PD-1/PD-L1-induced hypophysitis can present as an isolated manifestation of irAEs or be in association with other autoimmune diseases.