Therapy For Thyroid Cancer Research Articles

EDB-FN targeted probes for the surgical navigation, radionuclide imaging, and therapy of thyroid cancer.

Extradomain B of fibronectin (EDB-FN) is a promising diagnostic and therapeutic biomarker for thyroid cancer (TC). Here, we identified a high-affinity EDB-FN targeted peptide named EDBp (AVRTSAD) and developed three EDBp-based probes, Cy5-PEG4-EDBp(Cy5-EDBp), [18F]-NOTA-PEG4-EDBp([18F]-EDBp), and [177Lu]-DOTA-PEG4-EDBp ([177Lu]-EDBp), for the surgical navigation, radionuclide imaging, and therapy of TC. Based on the previously identified EDB-FN targeted peptide ZD2, the optimized EDB-FN targeted peptide EDBp was identified by using the alanine scan strategy. Three EDBp-based probes, Cy5-EDBp, [18F]-EDBp, and [177Lu]-EDBp, were developed for fluorescence imaging, positron emission tomography (PET) imaging, and radiotherapy in TC tumor-bearing mice, respectively. Additionally, [18F]-EDBp was evaluated in two TC patients. The binding affinity of EDBp to the EDB fragment protein (Kd = 14.4 ± 1.4nM, n = 3) was approximately 336-fold greater than that of the ZD2 (Kd = 4839.7 ± 361.7nM, n = 3). Fluorescence imaging with Cy5-EDBp facilitated the complete removal of TC tumors. [18F]-EDBp PET imaging clearly delineated TC tumors, with high tumor uptake (16.43 ± 1.008%ID/g, n = 6, at 1-h postinjection). Radiotherapy with [177Lu]-EDBp inhibited tumor growth and prolonged survival in TC tumor-bearing mice (survival time of different treatment groups: saline vs. EDBp vs. ABRAXANE vs. [177Lu]-EDBp = 8.00 d vs. 8.00 d vs. 11.67 d vs. 22.33 d, ***p < 0.001). Importantly, the first-in-human evaluation of [18F]-EDBp demonstrated that it had specific targeting properties (SUVmax value of 3.6) and safety. Cy5-EDBp, [18F]-EDBp, and [177Lu]-EDBp are promising candidates for the surgical navigation, radionuclide imaging, and radionuclide therapy of TC, respectively.

Accumulation of 131Iodine in the nasolacrimal sac/duct after radioiodine therapy for papillary thyroid cancer.

SPECT/CT is a powerful tool for assessing unexpected concentrations of radioiodine resulting from benign uptake in organs with sodium-iodide symporter (NIS) expression. We report a case of accumulation of 131Iodine in the nasolacrimal sac/duct after radioiodine therapy for papillary thyroid cancer. A whole-body scan was taken 3 days after the administration of 5.5 GBq of 131Iodine. SPECT/CT images localized the focal tracer uptake in the nasolacrimal sac/duct likely due to nasolacrimal duct obstruction secondary to prior radioiodine or iodine therapies. Hybrid SPECT/CT allows precise anatomical localization and help differentiate benign mimics of disease, which can alter patient management.

Racial and Ethnic Disparities in Appropriate Thyroid Cancer Treatment, Before and After the Release of the 2015 American Thyroid Association Guidelines.

The 2015 American Thyroid Association (ATA) guidelines reduced the recommended extent of therapy for low-risk thyroid cancers. Little is known about the impact of these changes on overall treatment patterns and on previously described racial/ethnic disparities in guideline-concordant care. This study aimed to assess trends in thyroid cancer care before and after release of the 2015 guidelines, with particular attention to racial/ethnic disparities. Patients with well-differentiated thyroid cancer were identified from the National Cancer Database (2010-2018). An interrupted time series design was used to assess trends in treatment before and after the 2015 guidelines. Appropriateness of surgical and radioactive iodine (RAI) treatment was determined based on the ATA guidelines, and the likelihood of receiving guideline-concordant treatment was compared between racial/ethnic groups. The study identified 309,367 patients (White 74%, Black 8%, Hispanic 9%, Asian 6%). Between 2010 and 2015, the adjusted probability of appropriate surgery was lower for Black (-2.1%; p<0.001), Hispanic (-1.0%; p<0.001), and Asian (-2.1%; p<0.001) patients than for White patients. After 2015, only Hispanic patients had a lower probability of undergoing appropriate surgical therapy (-2.6%; p=0.040). Similarly, between 2010 and 2015, the adjusted probability of receiving appropriate RAI therapy was lower for the Hispanic (-3.6%; p<0.001) and Asian (-2.4%; p<0.001) patients than for White patients. After 2015, the probability of appropriate RAI therapy did not differ between groups. Between 2010 and 2015, patients from racial/ethnic minority backgrounds were less likely than White patients to receive appropriate surgical and RAI therapy for thyroid cancer. After the 2015 guidelines, racial/ethnic disparities in treatment improved.

Management of Recurrent Well-Differentiated Thyroid Carcinoma in the Neck: A Comprehensive Review.

Surgery has been historically the preferred primary treatment for patients with well-differentiated thyroid carcinoma and for selected locoregional recurrences. Adjuvant therapy with radioactive iodine is typically recommended for patients with an intermediate to high risk of recurrence. Despite these treatments, locally advanced disease and locoregional relapses are not infrequent. These patients have a prolonged overall survival that may result in long periods of active disease and the possibility of requiring subsequent treatments. Recently, many new options have emerged as salvage therapies. This review offers a comprehensive discussion and considerations regarding surgery, active surveillance, radioactive iodine therapy, ultrasonography-guided percutaneous ablation, external beam radiotherapy, and systemic therapy for well-differentiated thyroid cancer based on relevant publications and current reference guidelines. We feel that the surgical member of the thyroid cancer management team is empowered by being aware and facile with all management options.

Recombinant or endogenous TSH for radioactive iodine therapy in thyroid cancer: state of knowledge and current controversies.

For patients undergoing radioiodine therapy of differentiated thyroid carcinoma (DTC), TSH stimulation prior to radioiodine therapy (RIT) can be achieved using thyroid hormone withdrawal (THW) or administration of recombinant human TSH (rhTSH). As THW can lead to nausea, headaches, vomiting, fatigue and dizziness secondary to transient acute hypothyroidism, rhTSH could be a good alternative. rhTSH has been administered in patients in order to stimulate TSH for RIT since 2005. According to the Martinique criteria formulated by the leading professional societies involved in care of patients with DTC, rhTSH can be applied in three settings: for remnant ablation, adjuvant treatment and treatment of known disease. Numerous studies have investigated the effects of rhTSH as a method of TSH stimulation on the thyroid cell, the systemic effects, biokinetics and clinical outcomes, however no consensus has been reached about many aspects of its potential use. rhTSH is able to stimulate sufficient TSH-levels (>30 mIU/L) and is hypothesized to decrease risks of tumor cell proliferation. As rhTSH-use avoids the transiently-impaired renal function associated with THW, radioiodine excretion is faster with the former, leading to to a lower iodine-131(I-131) uptake and a difference in fractional remnant uptake, effective half-life, mean residence time, and dose to the blood. Differences between rhTSH and THW were observed in radioiodine genotoxic effects and endothelial-dependent vasodilation and inflammation. For thyroid remnant ablation, THW and rhTSH lead to similar remnant ablation rates. For adjuvant therapy and treatment of known disease, insufficient trials have been conducted and future prospective studies are recommended.

External beam radiotherapy for thyroid cancer: Patients, complications, and survival

BackgroundPatterns of utilization of external beam radiation therapy (EBRT) in thyroid cancer are incompletely described. We characterize therapeutic intent, complications, and survival in thyroid cancer treated with EBRT. MethodsIn this retrospective study of 105 thyroid cancer patients treated with EBRT at one institution (2008–2018), the primary outcome was overall survival. Secondary outcomes included incomplete treatment, emergency department (ED) visits, weight change, and gastrostomy placement. ResultsDominant histopathology was differentiated (44%), anaplastic (45%) and poorly-differentiated (11%) disease. EBRT was mainly utilized for locoregional control (differentiated 87%, poorly-differentiated 75%, anaplastic 92%). Palliative EBRT was more common in poorly-differentiated disease (42%). Weight loss was greater in aggressive/advanced disease (differentiated 10 lb, poorly-differentiated 27 lb, anaplastic 18 lb). Anaplastic cancer had higher rates of gastrostomy (34%) and lowest rates of treatment completion (83%). ED encounters were common (differentiated 44%, poorly-differentiated 50%, anaplastic 45%). Gastrostomy was associated with mortality on multivariable analysis in non-anaplastic malignancy. ConclusionsEBRT was most frequently administered for locoregional control in thyroid cancer. Despite complications, the majority of patients completed EBRT therapy.

Ultrasonographic & biochemical analysis of thyroid bio-architecture for further pharmacological intervention in adult Arabian stallions & mares

Based on the growing attention to the Arabian horses with a lack of records regarding their normal physiological parameters, which are critically vital for disease diagnosis &convenient drug administration, we give great attention to their thyroid gland normalcy. The thyroid gland is one of the key players in regulating many physiological processes. Therefore, we tackled thyroid biology & morphology in 14 Arabian stallions & 18 Arabian mares from the beginning of March to the middle of April on animals from 4 to 19 years old. First, the blood samples taken from their jugular vein were used for hematological profile, lipid profile, glucose-coagulation axis & thyroid profile. Moreover, thyroid gland dimensions & volume were estimated using ultrasonography. Noteworthy, Arabian mares have significantly higher MCH & relative eosinophils than Arabian stallions, while Arabian stallions have significantly higher glucose levels than Arabian Mares. Interestingly, this study found that Arabian horses have a high level of Total T4 & low level of platelets count compared to other horses. These results pointed to the deiodinase inhibitors as a possible target therapy for hyperthyroidism & thyroid cancer in Arabian horses, making surgery a second option. Also, these results refer to the caution required before giving Arabian horses high plasma protein bounded drugs, especially anticoagulants. Also, sonographic results showed that the left lobe is larger than the right lobe in both genders, & the lobes volume is larger in Arabian horses compared to others. These results would guide the veterinarian during diagnosis & thyroidectomy.

Synthesis of lenvatinib-loaded upconversion@polydopamine nanocomposites for upconversion luminescence imaging-guided chemo-photothermal synergistic therapy of anaplastic thyroid cancer.

Anaplastic thyroid cancer (ATC) is the most malignant and aggressive of all classifications of thyroid cancer. ATC normally has poor prognosis after classic treatments such as surgery, endocrine therapy, radiotherapy and chemotherapy. Herein, a novel nanocomposite (named as UCNP@PDA@LEN) has been synthesized for chemo-photothermal therapy of ATC, which is based on a NaErF4:Tm3+@NaYbF4@NaYF4:Nd3+ upconverting nanoparticle (UCNP) as the core, a near-infrared light (NIR)-absorbing polydopamine (PDA) as the shell, and lenvatinib (LEN) as a chemotherapeutic drug. The as-prepared multifunctional UCNP@PDA@LEN exhibits excellent photothermal conversion capability (η = 30.7%), good photothermal stability and reasonable biocompatibility. Owing to the high UCL emission and good tumor accumulation ability, the UCL imaging of mouse-bearing ATC (i.e., C643 tumor) has been achieved by UCNP@PDA@LEN. Under 808 nm NIR laser irradiation, the UCNP@PDA@LEN shows a synergistic interaction between photothermal therapy (PTT) and chemotherapy (CT), resulting in strongly suppressed mouse-bearing C643 tumor. The results provide an explicit approach for developing theranostics with high anti-ATC efficiency.

Response to Surgery Assessments for Sparing Radioiodine Remnant Ablation in Intermediate-Risk Papillary Thyroid Cancer.

Using response to surgery when tailoring radioiodine (RAI) therapy for papillary thyroid cancer (PTC) is valued but lacks prospective validation. To spare RAI thyroid remnant ablation among patients with intermediate-risk PTCs using 3-tiered assessments with response to surgery highlighted, in addition to the risk of the recurrence stratification and TNM staging. Patients with no evidence of disease (NED) identified as excellent response (ER) or indeterminate response (IDR) to surgery were spared from RAI thyroid remnant ablation after informed consent and prospectively enrolled under active surveillance. Those involved in other trials or without sufficient follow-up data were excluded. Dynamic responses were followed and compared longitudinally. The main outcome measures were NED presenting as durable ER or IDR for over 12 months. Of the enrolled 215 patients, 47.4% (102/215) ER and 52.6% (113/215) IDR were identified regarding RAI decision-making. After a median of 23.6 (interquartile range 13.8-31.6) months, the share of ER increased to 82.8% (178/215) and IDR decreased to 16.3% (35/215), with 85 patients shifting from IDR to ER over time, only 0.5% (1/215) structural incomplete response and 0.5% (1/215) biochemical incomplete response observed. Successful remnant ablation was observed in 27.7% (26/94) of the patients completing 2 diagnostic whole-body scans after a median interval of 13.0 months, indicating a theranostic effect. In the 173 patients followed for over 12 months, the NED rate did not differ between ER and IDR subgroups (100% vs 97.9%, P = .20). Through the 3-tiered assessments with response to surgery highlighted, postoperative ER and IDR spared from RAI remnant ablation may indicate similar favorable responses in intermediate-risk patients with PTC during 23.6 months of follow-up.

Reprogramming of Cellular Metabolism and Its Therapeutic Applications in Thyroid Cancer.

Metabolism is a series of life-sustaining chemical reactions in organisms, providing energy required for cellular processes and building blocks for cellular constituents of proteins, lipids, carbohydrates and nucleic acids. Cancer cells frequently reprogram their metabolic behaviors to adapt their rapid proliferation and altered tumor microenvironments. Not only aerobic glycolysis (also termed the Warburg effect) but also altered mitochondrial metabolism, amino acid metabolism and lipid metabolism play important roles for cancer growth and aggressiveness. Thus, the mechanistic elucidation of these metabolic changes is invaluable for understanding the pathogenesis of cancers and developing novel metabolism-targeted therapies. In this review article, we first provide an overview of essential metabolic mechanisms, and then summarize the recent findings of metabolic reprogramming and the recent reports of metabolism-targeted therapies for thyroid cancer.

Optical diagnostic imaging and therapy for thyroid cancer.

Thyroid cancer, as one of the most common endocrine cancers, has seen a surge in incidence in recent years. This is most likely due to the lack of specificity and accuracy of its traditional diagnostic modalities, leading to the overdiagnosis of thyroid nodules. Although there are several treatment options available, they are limited to surgery and 131I radiation therapy that come with significant side effects and hence cannot meet the treatment needs of anaplastic thyroid carcinoma with very high malignancy. Optical imaging that utilizes optical absorption, refraction and scattering properties, not only observes the structure and function of cells, tissues, organs, or even the whole organism to assist in diagnosis, but can also be used to perform optical therapy to achieve targeted non-invasive and precise treatment of thyroid cancer. These applications of screening, diagnosis, and treatment, lend to optical imaging's promising potential within the realm of thyroid cancer surgical navigation. Over the past decade, research on optical imaging in the diagnosis and treatment of thyroid cancer has been growing year by year, but no comprehensive review on this topic has been published. Here, we review key advances in the application of optical imaging in the diagnosis and treatment of thyroid cancer and discuss the challenges and potential for clinical translation of this technology.

Lipid-Peptide-mRNA Nanoparticles Augment Radioiodine Uptake in Anaplastic Thyroid Cancer.

Restoring sodium iodide symporter (NIS) expression and function remains a major challenge for radioiodine therapy in anaplastic thyroid cancer (ATC). For more efficient delivery of messenger RNA (mRNA) to manipulate protein expression, a lipid-peptide-mRNA (LPm) nanoparticle (NP) is developed. The LPm NP is prepared by using amphiphilic peptides to assemble a peptide core and which is then coated with cationic lipids. An amphiphilic chimeric peptide, consisting of nine arginine and hydrophobic segments (6 histidine, C18 or cholesterol), is synthesized for adsorption of mRNA encoding NIS in RNase-free conditions. In vitro studies show that LP(R9H6) m NP is most efficient at delivering mRNA and can increase NIS expression in ATC cells by more than 10-fold. After intratumoral injection of NIS mRNA formulated in optimized LPm NP, NIS expression in subcutaneous ATC tumor tissue increases significantly in nude mice, resulting in more iodine 131 (131 I) accumulation in the tumor, thereby significantly inhibiting tumor growth. Overall, this work designs three arginine-rich peptide nanoparticles, contributing to the choice of liposome cores for gene delivery. LPm NP can serve as a promising adjunctive therapy for patients with ATC by restoring iodine affinity and enhancing the therapeutic efficacy of radioactive iodine.

Radioactive iodine in the treatment of Graves' disease: history and modern concept of radionuclide therapy

Radioactive iodine 131I is a theranostic isotope used both for diagnosis and therapy of benign thyroid diseases and thyroid cancer for 85 years. The formation of nuclear medicine is closely linked with the use of 131I. The history of radioiodine therapy began in 1941, when endocrinologist Saul Hertz for the first time used 131I to treat patients with Graves' disease. Since 1946 radioactive iodine 131I became widely available, and its effectiveness became public knowledge after reports on thyrotoxicosis treatment published in the Journal of the American Medical Association by multidisciplinary groups of scientists - physicists and endocrinologists. In 1951, isotope 131I became the first Food and Drug Administration approved RP for the treatment of thyroid disorders. Around the same time on the basis of the First Moscow Medical Institute studies on the use of radioiodine isotopes in patients with thyrotoxicosis began. The head of the Soviet group on the studying of radioactive iodine was the physician-scientist Vera Georgievna Spesivtseva. The research works of medical physicists Edith Quimby and Leonidas Marinelli in optimizing therapeutic strategies using radioactive substances in the late 1940s and the wording of the ALARA (As Low As Reasonably Achievable) principle of minimizing exposure of ionizing radiation by the International Commission on Radiological Protection in 1954 contributed to the greater introduction of radionuclides into the medicine.

High RPMB predicts poor disease-free survival of male N1 papillary thyroid cancer after adjuvant radioiodine therapy

The current recommendation for the use of adjuvant radioactive iodine (RAI) therapy in papillary thyroid cancer (PTC) after radical surgery is based on clinicopathological factors; however, this recommendation remains controversial. Our present study established a new biomarker, RPMB (promotor methylation burden of DNA repair genes (DRGs)), to identify a patient subgroup suitable for adjuvant RAI therapy. We defined RPMB as the ratio of methylated DRGs to the total number of DRGs. Methylation profiles of 498 PTC tumors and their clinical data were retrieved from the Cancer Genome Atlas (TCGA) database. DRGs of PTC subjects were found to be much more hypomethylated than controls across the whole profile (all p < 0.001). PTC patients with higher RPMBs tended to be ≥45 years old and female, and these PTCs were commonly unifocal, with N0 disease, wild-type BRAF, and mutated RAS. The subgroup analysis indicated that high RPMBs were significantly associated with poor disease-free survival (DFS) in male patients with PTC (HR = 4.855, 95% CI: 1.527–15.433, p = 0.007). Moreover, Kaplan–Meier analysis showed that high RPMBs could significantly predict poor DFS in male patients after R0 resection for N1 disease (HR: 5.431, 95% CI: 1.045–28.219, p = 0.024), and the p-value was very close to significance in these patients after adjuvant RAI therapy (HR: 6.269, 95% CI: 0.693–56.714, p = 0.062). Multivariate analysis indicated that both male sex (HR = 14.565, 95%CI: 2.153–98.507, p = 0.006) and high RPMBs (HR = 11.206, 95%CI: 1.622–77.405, p = 0.014) were independent unfavorable factors for DFS after adjuvant RAI therapy. Therefore, RPMB might be a potential predictor for identifying suitable male patients with PTC who can benefit from adjuvant RAI therapy.

OR09-3 Integrins as Potential Molecular Targets in Thyroid Cancer Imaging and Therapy

Abstract Background Integrins are cell adhesion receptors consisting of 24 transmembrane heterodimers generated from a combination of 18α integrin and 8β integrin subunits. A subset of integrins consists of receptors recognizing Arg-Gly-Asp (RGD) peptide motifs. One of the RGD-recognizing receptors is integrin αvβ3 that has been recently shown to play a role in neovascularization and progression of several cancers. Radiolabeled RGD analogs have emerged as potential imaging and therapeutic options in cancers characterized by a high expression of integrin αvβ3. Therefore, the aim of this study was to establish the expression of integrin αvβ3 in thyroid cancer (TC). Methods We analyzed the mRNA expression of integrin αvβ3 in 496 BRAF-like and RAS-like human TC tissue samples, including 65 paired samples of tumor vs normal tissue based on The Cancer Genome Atlas. We assessed the protein expression of integrin αvβ3 in 70 TC tissue samples and 10 normal thyroid tissues, as well as in 14 TC cell lines. BRAF-like or RAS-like tumor status was determined by BRS score based upon standard expression profiles ranging from -1 to 0 for BRAF-like cancer and 0 to 1 for RAS-like tumors. The association between BRS and αvβ3 expression was tested using the Spearman correlation coefficient (r). T-tests and paired T-tests were used to compare the continuous variables between the two groups as appropriate, and Kruskal-Wallis test was used for multiple group comparisons with an adjusted p-value of ≤ 0.05 as statistically significant. Results αv integrin subunit mRNA expression was significantly higher in TC than normal thyroid (log fold change 0.3, p=0.001), while the expression of the β3 subunit was similar between paired normal and malignant samples (log fold change -0.2, p=0.30). BRAF-like tumors were characterized by a higher mRNA expression of αvβ3 integrins as documented by a moderate negative correlation between BRS and αv (r=-0.5, p&amp;lt;0.001) as well as β3 (r=-0.27, p&amp;lt;0.001). Consistently, the BRAF-like TC cell lines OCUT2 (BRS=-1), TPC1 (BRS=-0.4), K1 (BRS=-0.29), as well as Hurthle cell TC cell line XTC1 (BRS=-0.46), were characterized by the highest αvβ3 mRNA and/or protein expression. Immunostaining revealed αv expression in all malignant samples, with classic papillary TC characterized by the highest expression as compared with follicular TC (p&amp;lt;0.001), poorly-differentiated TC (p=0.006) and normal thyroid (p&amp;lt;0.001). β3 protein expression had lower intensity than αv integrin and was present in 31.8% of papillary TC, 15% of follicular TC and was not detected in poorly-differentiated TC nor normal thyroid. Conclusions TC is characterized by a differential expression of αvβ3 integrin, which is particularly high in the most common type of TC - BRAF-like papillary TC. The αvβ3 integrin could potentially serve as a molecular target for imaging and therapy with radiolabeled RGD analogs in TC. Presentation: Saturday, June 11, 2022 12:00 p.m. - 12:15 p.m.

Novel target therapies for advanced thyroid cancers

Novel target therapies for advanced thyroid cancers

Pyruvate carboxylase promotes malignant transformation of papillary thyroid carcinoma and reduces iodine uptake

Previous studies have shown that pyruvate carboxylase (PC) plays a key role in the occurrence and progression of thyroid cancer (TC); however, the relationship between PC and iodine-refractory TC is unclear. Therefore, the present study aimed to investigate the molecular mechanism of PC in the malignant progression and loss of iodine uptake in papillary TC (PTC) and to explore the potential therapeutic effect of PC inhibitors in iodine-refractory PTC. PC increased cell proliferation, invasion, and metastasis, inhibited expression of the iodine metabolism-related genes TSHR, NIS, TPO, and TG, and decreased the iodine-uptake capacity by activating the mitogen-activated protein kinase/extracellular signal-regulated kinase pathway in PTC cell lines. Furthermore, the PC inhibitor ZY-444 effectively inhibited the activation of PC, reduced the malignant invasiveness, and restored the expression of iodine metabolism-related genes and the iodine-uptake capacity in PTC cells. These findings suggest that PC activation is involved in the progression of iodine-refractory TC and that PC inhibitors may represent a potentially novel targeted therapy for iodine-refractory TC.

Effect of COVID-19 pandemic on diagnosis and treatment of thyroid cancer in Brazil.

IntroductionThe COVID-19 pandemic delayed the diagnosis, treatment, and follow-up visits of patients with thyroid cancer. However, the magnitude with which these restrictions affected the Brazilian health care is still unknown.MethodsRetrospective analysis of thyroid cancer-related procedures performed in the Brazilian public health system from 2019 to 2021. Data were retrieved from the Department of Informatics of the Unified Health System (DATASUS). The following procedures were evaluated: fine-needle aspiration biopsies (FNABs), oncologic thyroidectomies, and radioiodine (RAI) therapies for thyroid cancer. The year of 2019 served as baseline control.ResultsCompared with 2019, FNABs, oncologic thyroidectomies, and RAI therapies performed in 2020 decreased by 29%, 17% and 28%, respectively. In 2021, compared with 2019, FNABs increased by 2%, and oncologic thyroidectomies and RAI therapies decreased by 5% and 25%, respectively. Most pronounced reductions were observed in the first months of the pandemic. In April 2020, FNABs decreased by 67%, oncologic thyroidectomies by 45%, and RAI therapies by 75%. In 2021, RAI therapies were the only procedure with a statistically significant decrease.ConclusionThe restrictions to public health care during the COVID-19 pandemic resulted in a significant reduction in diagnostic and treatment procedures for thyroid cancer in Brazil. The effects of these transitory gaps in thyroid cancer care, due to COVID-19, are still unclear.

The utility of low-iodine diet in preparation for thyroid cancer therapy with radioactive iodine-A cohort study.

Objective: A low-iodine diet (LID) of <50μ iodine/day is recommended as preparation for radioactive iodine (RAI) therapy in patients with differentiated thyroid cancer (DTC). The 24-h urinary iodine excretion (UIE) is utilized to evaluate the iodine-depleted status. The aim of this study was to test the association between UIE and progression-free survival (PFS). Patients and methods: In total, 70 patients with intermediate- or high-risk DTC, post-total thyroidectomy, adhered to 2 weeks of LID and had UIE measured before RAI therapy. A Cox regression model was performed to study the contribution of UIE to PFS. Results: The study group consisted of 68% (48/70) of women, aged 41.5 [IQR 31.0, 54.0] years, with tumor size 2.8 [IQR 1.8–4.5] cm, and presence of distant metastases in 22.9% (16/70) of patients. Patients were treated with 1–5 RAI dosages with the median cumulative activity of 150 [IQR 102–314] mCi (5.5 [IQR 3.8–11.6] GBq). During the follow-up of 3.7 [IQR 1.5–6.5] years, 21.4% (15/70) of patients had disease progression. The risk of progression was significantly higher in patients with UIE ≥200 µg/day at the time of RAI administration than in those with UIE <200 µg/day (HR 3.35, 95% CI 1.09–10.34, and p = 0.02). However, the multivariate Cox proportional hazards regression analysis adjusted for age, tumor size, and presence of distant metastases suggested that only distant metastases were independently significantly associated with the risk of progression (HR 5.80 (1.17–28.67), p = 0.03). Conclusions: Although UIE ≥200 µg/day might be associated with worse PFS in RAI-treated DTC patients, the presence of distant metastases is a strong independent predictor of progression. Less stringent LID might be sufficient to achieve a UIE of <200 µg/day.

NTRK and RET fusion-directed therapy in pediatric thyroid cancer yields a tumor response and radioiodine uptake

NTRK and RET fusion-directed therapy in pediatric thyroid cancer yields a tumor response and radioiodine uptake