Dynamic risk assessment in patients with differentiated thyroid cancer.

The current approach for patients with differentiated thyroid carcinoma should be individualized according to the risk of recurrence, and this stratification could be used to identify the risk of persistent/recurrent disease in three scenarios: preoperatively, immediately postoperatively, and during long-term follow-up. The initial risk of recurrence will tailor the management of the patient in the preoperative and immediate postoperative settings, while the dynamic risk, which considers the responses to treatment, could guide the decision-making process for remnant ablation and long-term management.This review provides a summary of the existing information regarding the dynamic risk of recurrence and recommended management for patients with differentiated thyroid cancer. The application of this approach is essential to avoid unnecessary treatments for most patients who will have a favorable prognosis. On the other hand, it allows specific therapeutic interventions for those patients at high risk of recurrence. In the future, analysis of tumor biology and prospective studies will surely improve the accuracy of recurrence risk prediction.

[Thyroid dysfunction in adults infected by human immunodeficiency virus]. / Disfuncion tiroidea en adultos infectados por el virus de inmunodeficiencia humana.

Patients infected with human immunodeficiency virus (HIV) have a higher prevalence of thyroid dysfunction when compared with the general population. The most frequently observed manifestations are euthyroid sick syndrome, Graves' disease and subclinical hypothyroidism. The relationship between the use of highly active antiretroviral therapy and the increased prevalence of thyroid dysfunction has been demonstrated in several series of patients. Grave's disease is recognized as a consequence of immune restitution syndrome. Besides, several studies have suggested an association between hypothyroidism and the use of nucleoside reverse transcriptase inhibitors, particularly stavudine and non-nucleoside reverse transcriptase inhibitors such as efavirenz. Further studies could provide additional evidence of the need for routine assessment of thyroid function in HIV-infected patients.

Primary resistance to selpercatinib in a patient with advanced medullary thyroid cancer.

Selpercatinib, a selective RET kinase inhibitor, has demonstrated remarkable efficacy in treating patients with advanced medullary (MTC) and differentiated thyroid cancer with RET alterations. Primary resistance to selpercatinib is a very uncommon situation, and its underlying mechanisms are poorly understood. We report the case of a 42-year-old female with advanced MTC harboring a somatic M918T RET mutation who exhibited a primary resistance to selpercatinib. Despite prompt treatment initiation after the diagnosis of progressive disease, the patient continued experiencing rapid spread of disease, characterized by the appearance of new metastatic lesions and increased tumor burden. Genomic analysis revealed no additional mutations associated with on-target or off-target resistance. This case highlights a rare clinical scenario of primary resistance to selpercatinib in advanced MTC. While secondary resistance mechanisms have been well-documented, primary resistance remains poorly understood. Possible explanations include tumor heterogeneity and activation of alternative signaling pathways that stills need to be elucidated. Emerging therapies targeting resistance mechanisms and next-generation RET inhibitors offer promising avenues for further investigation.

Ten years' real-life experience on the use of multikinase inhibitors in patients with advanced differentiated thyroid cancer.

PURPOSE: To evaluate objective response rates (ORR), progression-free survival (PFS), and overall survival (OS) associated with tyrosine kinase inhibitors (TKIs) in patients with radioiodine refractory differentiated thyroid cancer (RR-DTC). Additionally, to compare: (i) ORR and PFS among patients treated with lenvatinib and sorafenib; (ii) ORR and PFS among patients receiving lenvatinib as first-line vs. second-line and; (iii) adverse effects (AEs) observed in patients treated with these medications. METHODS: Retrospective analysis of RR-DTC adult patients treated with TKIs at the Division of Endocrinology, Hospital de Clinicas, University of Buenos Aires (March 2011-November 2023). RESULTS: Among 43 patients included in the study, 32 received sorafenib (30 as first-line and 2 as second-line), while 29 received lenvatinib (12 as first-line and 17 as second-line). The median PFS and OS for the entire cohort were 32.7 and 39.0 months, respectively. Lenvatinib demonstrated a significantly higher ORR compared to sorafenib (37.9% vs. 9.4%, p = 0.008). However, both drugs exhibited similar median PFS (23.2 vs. 16.0 months, p = 0.419). No significant difference was observed in ORR and PFS between patients receiving first-line vs. second-line lenvatinib. Sorafenib-treated patients experienced higher rates of hand-foot skin syndrome (69% vs. 41%, p = 0.032) and alopecia (25% vs. 3%, p = 0.018), whereas lenvatinib-treated patients had higher rates of proteinuria (31% vs. 0%, p < 0.001) and grade 3 hypertension (31% vs. 9%, p = 0.034). CONCLUSION: TKIs demonstrated efficacy and tolerability comparable to real-world data in RR-DTC. PFS was not statistically different between sorafenib and lenvatinib. Our study will help guide physicians in making informed decisions regarding treatment sequencing with TKIs in these patients.

Neoadjuvant Treatment of Locally Advanced Thyroid Cancer: A Preliminary Latin American Experience.

Background: Surgical resection is not always achievable in thyroid cancer patients. Neoadjuvant therapy is rarely used, but recent trends favor multikinase inhibitors or selective tyrosine kinase inhibitors. These aim to reduce tumor volume, enabling previously unfeasible surgeries. Patients and Methods: Consecutive patients with locally advanced malignant thyroid tumors who received systemic therapies with a neoadjuvant intention were included in this retrospective multicenter case series conducted in five Latin American referral centers. Primary outcomes were pre- versus postneoadjuvant response evaluations using the Response Evaluation Criteria in Solid Tumors, feasibility of surgery, and completeness of resection. Secondary outcomes were mortality and status at the last visit. Results: Twenty-seven patients were included in this analysis. Patients with unresectable differentiated thyroid cancer (DTC) or poorly differentiated thyroid cancer (PDTC) received sorafenib (n = 6) or lenvatinib (n = 12), those with medullary thyroid cancer (MTC) were treated with vandetanib (n = 5) or selpercatinib (n = 1), and those with anaplastic thyroid cancer (ATC) harboring a BRAFV600E mutation (n = 3) received dabrafenib and trametinib. The median patient age was 66 years (range 12-82), and 52% of the patients were female. In patients with PTC and PDTC, the median reduction in the diameter of the primary tumor was 25% (range 0-100%) after a median of 6 months of treatment. Surgical intervention was performed in 10 (55%) of the patients. Among these, six patients (60%) achieved R0/R1 resection status. Six patients with MTC had a median reduction in tumor diameter of 24.5% (range 1-49) after a median treatment time of 9.5 months. Only one patient receiving selpercatinib, with a tumoral reduction of 25% could undergo surgery, resulting in an R2 resection due to extensive mediastinal extension. Three patients with ATC showed a median tumor diameter reduction of 42% (range 6.7-50) after a median treatment time of 2 months. Two patients underwent surgical intervention and achieved R1 and R2 resection, respectively. Conclusions: While neoadjuvant therapy achieved tumoral responses, surgical resection was feasible in 55% of DTC, 33% of ATC, and 16% of MTC patients, with R0/R1 resection in 26% of the cohort, underscoring the need for patient selection and further research in this area.

Dabrafenib plus trametinib treatment in patients with anaplastic thyroid carcinoma: an Argentinian experience.

PURPOSE: To present our real-life experience with dabrafenib and trametinib (D-T) treatment in patients with BRAF V600E-mutated ATC in Argentina. PATIENTS Y METHODS: We included five patients from four different hospitals. The median age was 70 years, and 60% were male. The performance status at diagnosis was grade 0 in 60% and grade 2 in 40% of patients. Four patients could undergo total thyroidectomy; in one of them, surgical treatment was amenable due to the indication of D-T as neoadjuvant therapy. From the total cohort, the best response to treatment was complete response in 40%, partial response in 20%, and stable disease in 20%. The median duration of response was 20 weeks, ranging from 16 to 92 weeks. All patients experienced at least one adverse event (AE). Grade ≥3 AEs were observed in two (40%) patients. They were upper gastrointestinal bleeding and subclavian vein thrombosis. The median follow-up was 20 weeks (range: 16 to 92). CONCLUSION: This report contributes to illustrate the feasibility and effectiveness of D-T treatment in five patients with loco-regionally advanced and metastatic BRAF V600E-mutated ATC in a real-life setting. A multidisciplinary approach and rapid molecular-tailored testing are essential to begin this therapeutic option.

Active Surveillance of Small Metastatic Lymph Nodes as an Alternative to Surgery in Selected Patients with Low-Risk Papillary Thyroid Cancer: A Retrospective Cohort Study.

Background: It has been suggested that small metastatic lymph nodes (LNs) detected after initial surgery in patients with differentiated thyroid cancer (DTC) can be managed with active surveillance (AS). However, there is still concern regarding the clinical outcomes of these patients. The main aims of our study were as follows: (1) to assess the frequency of growth and the need of additional treatment in a group of patients with LN recurrences selected for AS, and (2) to determine predictive factors of LN progression. Methods: We retrospectively reviewed 856 clinical records from our DTC patient's database (May 2010 to January 2022). Eighty patients had suspicious cervical LNs on consecutive ultrasound (US) after initial surgery, but we included 50 patients with cytological confirmation of metastatic disease and at least 12 months follow-up. Exclusion criteria were as follows: any LN ≥2 cm or multiple LNs ≥1.5 cm in size, proximity to vital structures, PET-positive disease (standard uptake value ≥5), aggressive histology, and distant metastasis. Patients were followed with thyroglobulin (Tg) and thyroglobulin antibodies measurements on suppressive therapy and neck US every 6-12 months. LN growth was defined as an increase of ≥3 mm in any of its diameters. Results: A total of 50 patients had a median age of 41 years (range, 18-75). Most patients were women (80%) and had classical papillary thyroid cancer (86%). The mean size of the LNs was 10.1 ± 4.4 mm. After a median follow-up of 29 months (range, 12-144), 12 patients (24%) had an increase in size of the metastatic LN, 7 (58%) of whom were surgically removed. None of these seven patients had a structural incomplete response at the end of follow-up. The only variable that predicted an increase in LN size was a rise in Tg levels ≥0.5 ng/mL (p = 0.016). Based on a multivariate analysis, patients with increase in Tg levels ≥0.5 ng/mL had a significantly higher chance of developing LN growth (odds ratio [OR] 16.2 [confidence interval, CI 1.5-120.2], p = 0.020). The median progression-free survival rate was 6.6 years [CI 5.6-9.5]. Conclusion: AS of small LNs could be a feasible alternative to immediate surgery in properly selected patients.

Dynamic risk allows us to adequately select patients with differentiated thyroid cancer who do not require radioiodine treatment.

OBJECTIVE: The treatment of patients with differentiated thyroid cancer (DTC) was modified in the last decade towards a more individualized approach according to the risk of recurrence (RR). We compared the outcomes of patients with low and intermediate RR (LRR and IRR) who received or did not receive radioiodine remnant ablation (RRA) after assessing the dynamic risk. METHODS: We included 307 DTC patients with LRR and IRR submitted to total thyroidectomy. All patients were reclassified according to the dynamic risk stratification (low or high). Patients with high dynamic risk received RRA (141 patients). RESULTS: LRR patients who received RRA presented a frequency of structural incomplete response (SIR) of 5% at the end of the follow-up, compared to 2% in those who did not receive it (p=0.353). IRR patients treated with RRA had a frequency of SIR of 22%, compared to 5% in patients without RRA (p=0.008). CONCLUSION: This study demonstrates the usefulness of dynamic risk assessment to decide RRA in a cohort with a long-term follow-up. The lower prevalence of SIR at the end of the follow-up in patients who did not receive RRA highlights the adequate selection of those who would not benefit from RRA, even with an intermediate risk of recurrence.

Dynamic risk allows us to adequately select patients with differentiated thyroid cancer who do not require radioiodine treatment.

OBJECTIVE: The treatment of patients with differentiated thyroid cancer (DTC) was modified in the last decade towards a more individualized approach according to the risk of recurrence (RR). We compared the outcomes of patients with low and intermediate RR (LRR and IRR) who received or did not receive radioiodine remnant ablation (RRA) after assessing the dynamic risk. METHODS: We included 307 DTC patients with LRR and IRR submitted to total thyroidectomy. All patients were reclassified according to the dynamic risk stratification (low or high). Patients with high dynamic risk received RRA (141 patients). RESULTS: LRR patients who received RRA presented a frequency of structural incomplete response (SIR) of 5% at the end of the follow-up, compared to 2% in those who did not receive it (p=0.353). IRR patients treated with RRA had a frequency of SIR of 22%, compared to 5% in patients without RRA (p=0.008). CONCLUSION: This study demonstrates the usefulness of dynamic risk assessment to decide RRA in a cohort with a long-term follow-up. The lower prevalence of SIR at the end of the follow-up in patients who did not receive RRA highlights the adequate selection of those who would not benefit from RRA, even with an intermediate risk of recurrence.

Dramatic clinical response to dabrafenib plus trametinib in anaplastic thyroid carcinoma and the challenges faced during the COVID-19 pandemic.

Anaplastic thyroid carcinoma is the rarest tumor of the thyroid gland, representing less than 2% of clinically recognized thyroid cancers. Typically, it has an extremely rapid onset, fatal outcomes in most cases, and a median overall survival of 3 to 10 months despite aggressive multidisciplinary management. The presence of targetable mutations in anaplastic thyroid carcinoma patients is an opportunity for treatment when conventional therapeutics approaches are not effective, a frequent situation in the majority of patients. We present our experience in the management of a patient with unresectable anaplastic thyroid cancer who had a remarkable and rapid response to treatment with dabrafenib and trametinib during the COVID-19 pandemic. After four weeks of dabrafenib 150 mg twice daily plus trametinib 2 mg daily, he showed a dramatic reduction of the cervical mass around 90%. Nearly eight weeks under treatment with dabrafenib plus trametinib, the patient remains with minimal locoregional disease without distant metastases.

Thyroid cancer in the Era of COVID-19.

The recent coronavirus infectious disease (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is placing health systems in serious challenges worldwide. Shocking statistics each day has prompted the World Health Organization to officially declare the COVID-19 outbreak as a pandemic in March 2020. Preliminary studies have shown increased mortality in patients with solid cancers and infection by SARS-CoV-2. Until now, the evidence on the behavior of COVID-19 in patients with a history of thyroid cancer remains scarce, and most of the recommendations given are based on common sense. Therefore, in this viewpoint, we present a brief review of several challenges we are frequently facing during this pandemic and a series of recommendations based on what we have implemented in our clinical practice at a university hospital currently mostly dedicated to COVID-19.

Role of 18F-FDG-PET/CT in patients with differentiated thyroid cancer with biochemical incomplete or indeterminate response to treatment.

OBJECTIVES: To assess the value of 18F-FDG-PET/CT for detecting recurrent/persistent disease in patients with biochemical incomplete (BIR) or indeterminate response (IR) and to assess the impact of 18F-FDG-PET/CT on the therapeutic management of these patients. METHODS: The study included patients with BIR, in whom 18F-FDG PET/CT was used within the diagnostic algorithm from our database. Patients with IR referred to our hospital with the 18F-FDG PET/CT already performed were also enrolled. All patients had neck ultrasonography with no structural changes. A change in therapeutic approach was defined as repeat surgery; administration of external beam radiotherapy; and/or the start of systemic therapy. RESULTS: Sixty patients (85% women) aged 18-86 years were enrolled in this retrospective study. Of these, 75% had BIR and 25% IR. Increased FDG uptake suggesting locoregional lesions was seen in 40% of patients. Sensitivity, specificity, and diagnostic accuracy of 18F-FDG PET/CT to detect local disease were 95%, 87.5% and 90% respectively. The therapeutic approach was modified in 50% of patients with locoregional lesions. CONCLUSIONS: Our study confirmed that 18F-FDG-PET/CT is a useful tool for detecting locoregional recurrence in thyroid cancer patients with BIR or IR with conflicting findings in standard diagnostic procedures. In 50% of patients with locoregional lesions, there was an immediate change in the treatment approach.

Correction to: Dynamics of serum antithyroglobulin antibodies in patients with differentiated thyroid cancer.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Dynamics of serum antithyroglobulin antibodies in patients with differentiated thyroid cancer.

PURPOSE: Serum antithyroglobulin antibodies (sTgAb) affect the reliability of Tg measurement in patients with thyroid cancer. We compared the outcome of patients with detectable and undetectable sTgAb, stratified according to the initial risk of recurrence (RR); also the response to treatment in patients with detectable sTgAb treated with total thyroidectomy (TT) with and without radioiodine remnant ablation (RA) and the sTgAb trend in the long-term follow-up according to the initial response. METHODS: We included 432 patients submitted to TT, with or without RA; 106 patients had detectable sTgAb levels. Median follow-up was 53 months. RESULTS: There were no statistically significant differences considering presentation between negative or positive sTgAb subjects. The frequency of structural incomplete response (SIR) in low, intermediate, and high RR was similar. Undetectable sTgAb in patients was achieved in a median of 16 months in ablated patients compared with 11 months in those without RA (p = 0.0232). Patients without RA had a higher rate of undetectable sTgAb during the first 12 months. A SIR was observed in 3% of patients with declining sTgAb, in 19% of those with stable levels, and in 43% with increasing sTgAb (p = 0.004). The status of no evidence of disease was achieved more frequently in patients with initial sTgAb levels < 200 mUI/l, independently of the initial RR. CONCLUSIONS: There was no impact of sTgAb on the initial clinical presentation and the response to therapy in low-risk patients treated with or without RA. sTgAb trend is more useful than an absolute value to predict a SIR.

Real-life use of lenvatinib in patients with differentiated thyroid cancer: experience from Argentina.

PURPOSE: To describe the experience with radioiodine-resistant differentiated thyroid cancer (RR-DTC) patients treated with lenvatinib in two university hospitals from Argentina. METHODS: Adult patients with a diagnosis of RR-DTC treated with lenvatinib from April 2017 to February 2020 were registered into a retrospective database. Primary objectives were assessment of progression-free survival (PFS) and tumor response evaluated according to RECIST v 1.1. Adverse events (AEs) were evaluated by using Common Terminology Criteria for Adverse Events v5.0. RESULTS: Twenty-two patients were treated with lenvatinib, 13 of whom had previously received one or more multikinase inhibitors. Median duration of treatment was 7.1 months (2.2-24). Best overall response was complete response in one patient (4.5%), partial response in seven (31.8%), stable disease in seven (31.8%), and progressive disease in six (27.3%). Median PFS was 13.7 months (95% CI 3.2-24.2). All patients experienced at least one AE. Grade ≥3 AEs were observed in eight (36.4%) patients. Hypertension was the most frequent AE (63.6%) and the most common grade ≥3 AE (22.7%). Definitive withdrawal was necessary in two patients due to recurrent proteinuria (9%). CONCLUSIONS: Tumor responses and PFS in our study were in line with other real-life clinical data and they seem to be inferior to the reported in the SELECT trial, probably related to the higher number of patients with prior MKI therapy, comorbidities, and poor performance status. Although virtually all patients experienced AEs, most of them were manageable and rarely a definitive withdrawal was necessary.

Rare complications of multikinase inhibitor treatment.

OBJECTIVE: The advent of multikinase inhibitor (MKI) therapy has led to a radical change in the treatment of patients with advanced thyroid carcinoma. The aim of this manuscript is to communicate rare adverse events that occurred in less than 5% of patients in clinical trials in a subset of patients treated in our hospital. SUBJECTS AND METHODS: Out of 760 patients with thyroid cancer followed up with in our Division of Endocrinology, 29 (3.8%) received treatment with MKIs. The median age at diagnosis of these patients was 53 years (range 20-70), and 75.9% of them were women. Sorafenib was prescribed as first-line treatment to 23 patients with differentiated thyroid cancer and as second-line treatment to one patient with advanced medullary thyroid cancer (MTC). Vandetanib was indicated as first-line treatment in 6 patients with MTC and lenvatinib as second-line treatment in two patients with progressive disease under sorafenib treatment. RESULTS: During the follow-up of treatment (mean 13.7 ± 7 months, median 12 months, range 6-32), 5/29 (17.2%) patients presented rare adverse events. These rare adverse effects were: heart failure, thrombocytopenia, and squamous cell carcinoma during sorafenib therapy and squamous cell carcinoma and oophoritis with intestinal perforation during vandetanib treatment. CONCLUSIONS: About 3 to 5 years after the approval of MKI therapy, we learned that MKIs usually lead to adverse effects in the majority of patients. Although most of them are manageable, we still need to be aware of potentially serious and rare or unreported adverse effects that can be life-threatening.

Thyroglobulin levels measured at the time of remnant ablation to predict response to treatment in differentiated thyroid cancer after thyroid hormone withdrawal or recombinant human TSH.

The objective of our study was to evaluate the prognostic value of stimulated thyroglobulin levels at the moment of remnant ablation for predicting an initial excellent or a structural incomplete response to treatment according to the risk of recurrence in patients with differentiated thyroid cancer. Patients were divided into two groups according to the preparation mode for remnant ablation (thyroid hormone withdrawal or recombinant human TSH). We included 219 patients followed-up for at least for 24 months after remnant ablation. The primary endpoint was the best response to initial therapy assessed in the first 9-18 months of follow-up. An excellent response was observed in 45.1 % of patients prepared after recombinant human TSH compared to 44.6 % of patients prepared after thyroid hormone withdrawal (P = NS). The cutoff value of thyroglobulin level after recombinant human TSH for predicting an excellent response was 8 ng/ml (n = 51), with a sensitivity of 73.9 %, and a positive predictive value of 61 %. It was similar for patients with low vs. intermediate to high risk of recurrence. This cutoff value for thyroglobulin level after thyroid hormone withdrawal was 22 ng/ml (n = 168), with a sensitivity of 94.7 % and a positive predictive value of 61.7 %. In the thyroid hormone withdrawal group the thyroglobulin cutoff level was 12 ng/ml for low-risk patients compared to 16 ng/ml for those with intermediate to high risk of recurrence (P = 0.003). The cutoff value of the thyroglobulin level for predicting a structural incomplete response to initial treatment was 20 ng/ml after rhTSH, with a negative predictive value of 91.4 %. This level was higher in thyroid hormone withdrawal group, and it was established at 25 ng/ml, with a negative predictive value of 97.7 %. The stimulated Tg level seems to be different depending on the preparation mode (rhTSH or THW) for RA. It has a high NPV to predict the absence of a structural incomplete response and it is also a good predictor of the initial excellent response and the NED status at the end of follow-up.

Dynamic risk allows us to adequately select patients with differentiated thyroid cancer who do not require radioiodine treatment

ABSTRACT Objective: The treatment of patients with differentiated thyroid cancer (DTC) was modified in the last decade towards a more individualized approach according to the risk of recurrence (RR). We compared the outcomes of patients with low and intermediate RR (LRR and IRR) who received or did not receive radioiodine remnant ablation (RRA) after assessing the dynamic risk. Materials and methods: We included 307 DTC patients with LRR and IRR submitted to total thyroidectomy. All patients were reclassified according to the dynamic risk stratification (low or high). Patients with high dynamic risk received RRA (141 patients). Results: LRR patients who received RRA presented a frequency of structural incomplete response (SIR) of 5% at the end of the follow-up, compared to 2% in those who did not receive it (p=0.353). IRR patients treated with RRA had a frequency of SIR of 22%, compared to 5% in patients without RRA (p=0.008). Conclusions: This study demonstrates the usefulness of dynamic risk assessment to decide RRA in a cohort with a long-term follow-up. The lower prevalence of SIR at the end of the follow-up in patients who did not receive RRA highlights the adequate selection of those who would not benefit from RRA, even with an intermediate risk of recurrence.

Dramatic clinical response to dabrafenib plus trametinib in anaplastic thyroid carcinoma and the challenges faced during the COVID-19 pandemic

SUMMARY Anaplastic thyroid carcinoma is the rarest tumor of the thyroid gland, representing less than 2% of clinically recognized thyroid cancers. Typically, it has an extremely rapid onset, fatal outcomes in most cases, and a median overall survival of 3 to 10 months despite aggressive multidisciplinary management. The presence of targetable mutations in anaplastic thyroid carcinoma patients is an opportunity for treatment when conventional therapeutics approaches are not effective, a frequent situation in the majority of patients. We present our experience in the management of a patient with unresectable anaplastic thyroid cancer who had a remarkable and rapid response to treatment with dabrafenib and trametinib during the COVID-19 pandemic. After four weeks of dabrafenib 150 mg twice daily plus trametinib 2 mg daily, he showed a dramatic reduction of the cervical mass around 90%. Nearly eight weeks under treatment with dabrafenib plus trametinib, the patient remains with minimal locoregional disease without distant metastases.

Partial response to sorafenib treatment associated with transient grade 3 thrombocytopenia in a patient with locally advanced thyroid cancer.

Advanced radioactive refractory and progressive or symptomatic differentiated thyroid carcinoma (DTC) is a rare condition. Sorafenib was recently approved for the treatment of these patients. We present the case of a 67 year old woman diagnosed with DTC who underwent a total thyroidectomy with central, lateral-compartment neck dissection and shaving of the trachea and esophagus due to tumor infiltration. A local recurrence was detected 14 months later requiring, additionally, two tracheal rings resection. The patient received a cumulative 131I dose of 650 mCi and developed dysphagia and dyspnea 63 months after initial surgery. A 18FGD-PET/CT showed progression of the local mass associated to hypermetabolic pulmonary nodules. Sorafenib 800 mg/day was then prescribed. A dose reduction to 400 mg/day was necessary due to grade 3 thrombocytopenia that appeared four months after drug prescription. Platelet count went to normal after this dose reduction. Five months after initiation of sorafenib, a partial response of the local mass with significant intra-tumoral necrosis was observed. We conclude that sorafenib is a valid option for locally advanced DTC and that the platelet count should be evaluated regularly because it seems that thrombocytopenia might be more frequently observed in DTC than in other types of tumors.