Timing of multikinase inhibitor initiation in differentiated thyroid cancer

Advances in the selection and timing of postoperative radioiodine treatment in patients with differentiated thyroid carcinoma

Differentiated thyroid cancer (DTC) is the most common endocrine malignancy. Patients who receive systematic care typically have a better prognosis. RAI treatment plays a key role in eradicating any remaining thyroid lesions in DTC patients, hence decreasing the risk of distant metastases and cancer recurrence. As research continues to advance, RAI treatment is becoming more and more individualized. Because of the excellent prognosis for DTC patients, there is a relatively broad window for RAI treatment, making it easy to overlook when to receive RAI treatment. However, research on this issue can help patients with varying recurrence risk stratification make better decisions about when to begin RAI treatment following surgery, and physicians can schedule patients based on the severity of their disease. This will improve patient prognosis and lessen needless anxiety in addition to helping solve the problems of unjust healthcare resource distribution. In this review, we will mainly discuss the target population of RAI treatment as well as studies that examine the impact of RAI treatment timing on patient outcomes. In an effort to discourage DTC patients and physicians from selecting RAI therapy at random, we also review the possible negative effects of this treatment.

Multikinase Inhibitors for the Treatment of Asymptomatic Radioactive Iodine-Refractory Differentiated Thyroid Cancer: Global Noninterventional Study (RIFTOS MKI)

Background: Sorafenib and lenvatinib are multikinase inhibitors (MKIs) approved for patients with radioactive iodine-refractory (RAI-R) differentiated thyroid cancer (DTC). There is no consensus on when to initiate MKI treatment. The objective of this study was to evaluate time to symptomatic progression (TTSP) in patients with RAI-R DTC for whom the decision to treat with an MKI was made at study entry. Methods: International, prospective, open-label, noninterventional cohort study (NCT02303444). Eligible patients had asymptomatic progressive RAI-R DTC, with ≥1 lesion ≥1 cm in diameter and life expectancy ≥6 months. The decision to treat with an MKI was at the treating physician's discretion. Primary endpoint was TTSP from study entry. Two cohorts were evaluated: patients for whom a decision to initiate an MKI was made at study entry (Cohort 1) and patients for whom there was a decision not to initiate an MKI at study entry (Cohort 2). Cohorts were compared descriptively. Results: The full analysis set (FAS) comprised 647 patients. The median duration of observation was 35.5 months (range <1-59.4). Of 344 MKI-treated patients, 209 received sorafenib, 191 received lenvatinib, and 19 received another MKI at some point. Median TTSP was 55.4 months (interquartile range [IQR] 18.6-not estimable [NE]) overall, 55.4 months (IQR 15.2-NE) in Cohort 1 (n = 169), and 51.4 months (IQR 20.0-NE) in Cohort 2 (n = 478). TTSP ≥36 months was achieved in 64.5% of patients overall, 59.5% of patients in Cohort 1, and 66.4% of patients in Cohort 2. Median overall survival from classification as RAI-R was 167 months and median progression-free survival from start of MKI therapy was 19.2 months and from start of sorafenib therapy 16.7 months. Among sorafenib-treated patients, 70% had dose modifications, 35% had a dose reduction, 89% experienced ≥1 treatment-emergent adverse event (TEAE), and 82% experienced ≥1 drug-related TEAE. Conclusions: This real-world study provides valuable insight into outcomes in patients with asymptomatic, progressive RAI-R DTC under observation or receiving MKI treatment. TTSP in the FAS provides insight into the current prognosis for patients with RAI-R DTC in the era of MKIs. Registration: NCT02303444.

Nutrition in Advanced Thyroid Cancer Patients

In the last decade, multikinase inhibitors (MKIs) have changed the paradigm of treatment of advanced and progressive thyroid cancer. Compared with the traditional treatment with chemotherapy and radiotherapy, these new drugs have shown a good efficacy in controlling the neoplastic disease, and also a different toxicity profile compared to traditional chemotherapy, milder but still present and involving mainly the nutritional profile. Weight loss, nausea, anorexia, stomatitis, diarrhea may be associated with malnutrition and cancer-related cachexia. The latter is characteristic of the advanced cancer stage and may be present before starting MKIs, or may develop afterwards. Adverse events with nutritional impact may cause a significant impairment of quality of life, often requiring dose reduction and sometimes drug discontinuation, but with a lower efficacy on the neoplastic disease. The aim of this paper was to discuss the role of nutritional therapy in advanced thyroid cancer and the importance of prevention, early recognition and careful management of malnutrition and cachexia during systemic therapy with MKIs.

Kinase-Inhibitors in Iodine-Refractory Differentiated Thyroid Cancer-Focus on Occurrence, Mechanisms, and Management of Treatment-Related Hypertension

Differentiated thyroid cancer (DTC) usually has a good prognosis when treated conventionally with thyroidectomy, radioactive iodine (RAI) and thyroid-stimulating hormone suppression, but some tumors develop a resistance to RAI therapy, requiring alternative treatments. Sorafenib, lenvatinib and cabozantinib are multikinase inhibitors (MKIs) approved for the treatment of RAI-refractory DTC. The drugs have been shown to improve progression-free survival (PFS) and overall survival (OS) via the inhibition of different receptor tyrosine kinases (RTKs) that are involved in tumorigenesis and angiogenesis. Both sorafenib and lenvatinib have been approved irrespective of the line of therapy for the treatment of RAI-refractory DTC, whereas cabozantinib has only been approved as a second-line treatment. Adverse effects (AEs) such as hypertension are often seen with MKI treatment, but are generally well manageable. In this review, current clinical studies will be discussed, and the toxicity and safety of sorafenib, lenvatinib and cabozantinib treatment will be evaluated, with a focus on AE hypertension and its treatment options. In short, treatment-emergent hypertension (TE-HTN) occurs with all three drugs, but is usually well manageable and leads only to a few dose modifications or even discontinuations. This is emphasized by the fact that lenvatinib is widely considered the first-line drug of choice, despite its higher rate of TE-HTN.

Management of VEGFR-Targeted TKI for Thyroid Cancer

Recent advances in the development of multitarget tyrosine kinase inhibitors (MTKIs), which mainly target the vascular endothelial growth factor receptor (VEGFR), have improved prognoses and dramatically changed the treatment strategy for advanced thyroid cancer. However, adverse events related to this inhibition can interrupt treatment and sometimes lead to discontinuation. In addition, they can be annoying and potentially jeopardize the subjects' quality of life, even allowing that the clinical outcome of patients with advanced thyroid cancer remains limited. In this review, we summarize the potential mechanisms underlying these adverse events (hypertension, proteinuria and renal impairment, hemorrhage, fistula formation/gastrointestinal perforation, wound healing, cardiovascular toxicities, hematological toxicity, diarrhea, fatigue, and acute cholecystitis), their characteristics, and actual management. Furthermore, we also discuss the importance of related factors, including alternative treatments that target other pathways, the necessity of subject selection for safer administration, and patient education.

Clinical Study of Virtual Reality Augmented Technology Combined with Contrast-Enhanced Ultrasound in the Assessment of Thyroid Cancer

Thyroid cancer has become the most common malignant tumor in the endocrine system, and its global incidence has been showing an upward trend. The diagnosis methods of thyroid cancer include ultrasound, fine-needle aspiration cytology, and neck CT, but the single ultrasound feature cannot simultaneously take into account the sensitivity and specificity of more than 85% when diagnosing thyroid cancer. The development of virtual technology can significantly improve the diagnosis of the thyroid gland. Based on this, this article proposes a clinical study of virtual reality technology combined with contrast-enhanced ultrasound in the assessment of thyroid cancer. This article uses a variety of methods, such as literature method, mathematical statistics, and experimental research, in-depth study of the theoretical cornerstones of virtual reality augmented technology, the application status of ultrasound contrast technology, and so on. And a fuzzy mean clustering algorithm was proposed to identify ultrasound images. Then, a clinical experiment of virtual reality augmented technology combined with contrast-enhanced ultrasound was designed to evaluate thyroid cancer, which included comparison of contrast-enhanced ultrasound signs, analysis of enhancement results, multifactor logistic analysis, and diagnostic efficacy analysis of ultrasound signs. The combined application of virtual reality augmented technology and contrast-enhanced ultrasound in the study of thyroid cancer has a sensitivity and specificity exceeding 85% as the diagnosis boundary changes, and the accuracy of the combined diagnosis is relatively high.

Long-term management of lenvatinib-treated thyroid cancer patients: a real-life experience at a single institution

PURPOSE

The efficacy of lenvatinib for advanced and progressive radioactive iodine refractory differentiated thyroid cancer is well established. Herein, we retrospectively evaluated the long-term safety and efficacy of lenvatinib in 23 patients treated at a single Institution.

METHODS

Clinical data of all patients treated for a differentiated thyroid cancer with lenvatinib from April 2015 to September 2020 were retrospectively analyzed.

RESULTS

A total of 23 patients were included. In all, 21 patients received lenvatinib as first-line systemic therapy. Median age at initiation of lenvatinib treatment was 68 (44-90) years. Median duration of the study from initiation of lenvatinib to study end was 23 (2-65) months. The indication for lenvatinib treatment was documented progression of distant metastases in 20 patients and of locally advanced disease in the other 3 and median duration of lenvatinib therapy was 15 (2-64) months. Best treatment responses were: partial response in 6 patients, stable disease in 14, progressive disease in 1, and not evaluable in 2. Median progression-free survival was 25 months (95% CI: 12-40) and median overall survival was 46 months (95% CI: 28-65). Three patients had to discontinue lenvatinib treatment due to serious adverse events and no drug-related death was observed. Ten patients continued lenvatinib for more than 24 months and the only newly registered adverse event after this period of time was one case of G2 proteinuria. Six patients continued lenvatinib treatment beyond documented tumor progression due to oligoprogression or slowly progressive disease (median time 18.5 months, 8-42 months). A total of 14 patients were alive at the end of the study: 11 showed partial response/stable disease on lenvatinib, including 3 who had a stable disease after local ablative therapy for oligoprogressive metastases; 3 had to change treatment, including 2 for lenvatinib-related serious adverse events and 1 for progressive disease.

CONCLUSIONS

Long-term lenvatinib treatment is safe and some patients may experience persistent long-term control of the disease. Late treatment-related AEs rarely occurred. Oligoprogressive and slowly progressive disease can be managed without treatment withdrawal as long as there are some clinical benefits.

Clinical Indications for Treatment with Multi-Kinase Inhibitors in Patients with Radioiodine-Refractory Differentiated Thyroid Cancer

Differentiated thyroid cancer is usually a slow-growing disease, even if the patients develop distant metastasis. For recurrent or metastatic disease, radioactive iodine therapy is a standard treatment. However, the disease gradually progresses in some of the patients and can ultimately develop into life-threatening conditions. For patients with progressive radioactive iodine-refractory differentiated thyroid cancer (RR-DTC), multi-kinase inhibitors (MKIs) including sorafenib and lenvatinib prolonged progression-free survival compared with placebo in pivotal randomized phase 3 trials, although the benefit in overall survival has not been clearly confirmed, possibly because the patients who received placebo were permitted to cross-over to lenvatinib upon disease progression. Moreover, the adverse events related to MKIs were not negligible. Therefore, the optimal timing of MKI initiation has long been controversial, and physicians should consider various patient and disease factors. Herein, we comprehensively review the clinical factors that can be helpful in determining the initiation of MKIs for patients with RR-DTC.

Multikinase inhibitors in thyroid cancer: timing of targeted therapy

In the 9 years since the publication of our 2011 review of targeted treatment of thyroid cancer with multikinase inhibitors, much has changed in the landscape of this heterogeneous disease. New multikinase and selective inhibitor treatments for medullary thyroid cancer, radioiodine-refractory thyroid cancer and anaplastic thyroid cancer have completed trials and improved progression-free survival. Many physicians are concerned by dose-limiting adverse effects of these drugs and are wary to begin treatment in patients who are systemically well but have marked disease burden, which makes the timing of treatment initiation challenging. Published mechanistic data on tyrosine kinase inhibitors (TKIs) have helped guide our understanding of how to dose effectively with these drugs. A major goal in TKI therapy is to optimize inhibition of oncogenic kinase drivers while maintaining patient quality of life. Real-world data have now been published on how TKIs have fared outside the clinical trial environment. In this Review, we provide a summary of published data on the efficacy of TKIs in clinical practice, to provide clinicians with a more realistic view of how their patients will manage and respond to TKI therapy. Furthermore, we review the data on mechanisms of inhibition, outcomes and adverse effects of TKIs and provide an update on targeted treatment of thyroid cancer, focusing on optimizing the timing of treatment initiation.

Personalized treatment for differentiated thyroid cancer: current data and new perspectives

More conservative and personalized treatment options have been developed in recent years to face the rising diagnosis of low-risk differentiated thyroid carcinoma (DTC). The present review describes the change towards a more risk-adapted management either in the treatment or in the follow-up of DTC. Particular attention is given to the innovations introduced by the latest guidelines for low-risk tumors, starting from the most appropriate extension of surgery up to the postoperative management. The emerging role of active surveillance for low-risk microcarcinoma is discussed, as well as the development of percutaneous strategies in the setting of malignant thyroid disease. The recent use of approved new systemic target therapies for advanced radioiodine refractory thyroid cancer is reported, together with the description of new compounds in trial. Finally, we provide some considerations to improve the risk evaluation in a presurgical setting, especially related to the rising role of genetics, to enable better risk-based cancer management and personalized treatment choices.

Clinicopathological Features Predict Outcomes in Patients with Radioiodine-Refractory Differentiated Thyroid Cancer Treated with Sorafenib: A Real-World Study

BACKGROUND

Because beneficial response and progression-free survival (PFS) were achieved by well-designed clinical trials with tyrosine kinase inhibitors (TKIs) in patients with progressive radioiodine-refractory differentiated thyroid cancer (RR-DTC), the overall survival (OS) and improvement of therapeutic outcomes in the real world have been anticipated.

SUBJECTS, MATERIALS, AND METHODS

This prospective, single-center, real-world study assessed the predictive significance of clinicopathological features on disease control rate (DCR), objective response rate (ORR), PFS, and OS in a cohort of 72 patients with progressive RR-DTC treated with sorafenib at an initial dose of 200 mg twice daily.

RESULTS

Disease control, objective response, and biochemical effectiveness were achieved in 73.3%, 21.7%, and 77.9% of patients, respectively. The median PFS and OS were 17.6 and 28.9 months, respectively. Multivariate analyses showed that hand-foot syndrome (HFS) was an independent predictor for better DCR and ORR, and ¹³¹ I-avidity for higher ORR. In univariate analyses, longer PFS and OS were observed in patients with Eastern Cooperative Oncology Group performance status (ECOG PS) ≤2, pathologically well DTC, lung-only metastasis, absence of bone metastasis, biochemically nonineffective response, HFS, or radiological disease control. In multivariate analyses, only well DTC and ECOG PS ≤2 remained as independent prognostic factors for more favorable PFS and OS, respectively, whereas the absence of bone metastasis and biochemically nonineffective response independently predicted superior PFS and OS.

CONCLUSION

This study demonstrated that clinicopathological features might play a vital role in predicting therapeutic outcomes in patients with progressive RR-DTC treated with sorafenib, warranting further optimization of candidates for TKIs.

IMPLICATIONS FOR PRACTICE

This prospective, single-center, real-world study was designed to investigate the significance of clinicopathological features in predicting response, progression-free survival, and overall survival in patients with progressive radioiodine-refractory differentiated thyroid cancer (DTC) treated with sorafenib. Multivariate analyses showed that hand-foot syndrome was an independent predictor for better response. Meanwhile, well DTC, Eastern Cooperative Oncology Group performance status ≤2, biochemically nonineffective response, and the absence of bone metastasis were independent prognostic factors for more favorable survival. This study demonstrated that clinicopathological features might play a vital role in predicting outcomes in sorafenib-treated patients with radioiodine-refractory DTC, warranting optimization of indications.

Mouse models of thyroid cancer: Bridging pathogenesis and novel therapeutics

Due to a global increase in the incidence of thyroid cancer, numerous novel mouse models were established to reveal thyroid cancer pathogenesis and test promising therapeutic strategies, necessitating a comprehensive review of translational medicine that covers (i) the role of mouse models in the research of thyroid cancer pathogenesis, and (ii) preclinical testing of potential anti-thyroid cancer therapeutics. The present review article aims to: (i) describe the current approaches for mouse modeling of thyroid cancer, (ii) provide insight into the biology and genetics of thyroid cancers, and (iii) offer guidance on the use of mouse models for testing potential therapeutics in preclinical settings. Based on research with mouse models of thyroid cancer pathogenesis involving the RTK, RAS/RAF/MEK/ERK, PI3K/AKT/mTOR, SRC, and JAK-STAT signaling pathways, inhibitors of VEGFR, MEK, mTOR, SRC, and STAT3 have been developed as anti-thyroid cancer drugs for "bench-to-bedside" translation. In the future, mouse models of thyroid cancer will be designed to be ''humanized" and "patient-like," offering opportunities to: (i) investigate the pathogenesis of thyroid cancer through target screening based on the CRISPR/Cas system, (ii) test drugs based on new mouse models, and (iii) explore the underlying mechanisms based on multi-omics.

2019 European Thyroid Association Guidelines for the Treatment and Follow-Up of Advanced Radioiodine-Refractory Thyroid Cancer

The vast majority of thyroid cancers of follicular origin (TC) have a very favourable outcome, but 5-10% of cases will develop metastatic disease. Around 60-70% of this subset, hence less than 5% of all patients with TC, will become radioiodine refractory (RAI-R), with a significant negative impact on prognosis and a mean life expectancy of 3-5 years. Since no European expert consensus or guidance for this challenging condition is currently available, a task force of TC experts was nominated by the European Thyroid Association (ETA) to prepare this document based on the principles of clinical evidence. The task force started to work in September 2018 and after several revision rounds, prepared a list of recommendations to support the treatment and follow-up of patients with advanced TC. Criteria for advanced RAI-R TC were proposed, and the most appropriate diagnostic tools and the local, systemic and palliative treatments are described. Systemic therapy with multikinase inhibitors is fully discussed, including recommendations on how to start it and at which dosage, on the duration of treatment, and on the management of side effects. The appropriate relationship between the specialist and the patient/family as well as ethical issues are covered. Based on the available studies and on personal experience, the experts provided 39 recommendations aimed to improve the management of advanced RAI-R TCs. Above all of them is the indication to treat and follow these patients in a specialized setting which allows the interaction between several specialists in a multidisciplinary team.

Efficacy and safety of lenvatinib in an elderly patient with metastatic papillary thyroid carcinoma and cardiological comorbidity: a case report

Lenvatinib significantly prolonged progression-free survival versus placebo in patients with radio-iodine refractory differentiated thyroid carcinoma. However, the primary adverse effects of any grade that occurred in >40% of patients in the lenvatinib group of the Phase III SELECT trial was hypertension (67.8%). Therefore, this drug should be used with caution in patients with cardiological morbidity. Here, we describe the case of a 73-year-old man with hypertension, obesity and chronic atrial fibrillation, who received lenvatinib for 6 months in the absence of cardiological symptoms.

Embolization of iliac metastasis during lenvatinib treatment in patient with advanced Hürthle cell thyroid carcinoma

Lenvatinib is a tyrosine kinase inhibitor (TKI) with antiproliferative and antiangiogenic effects indicated for the treatment of progressive, locally advanced or metastatic progressive thyroid carcinoma, refractory to radioactive iodine therapy. Antiangiogenic therapies induce ischemic necrosis of tumor tissue, with increased risk of hemorrhagic complications. The management of hemorrhagic risk is based on precautionary measures and for any surgical procedure, it is advised to interrupt the treatment in order to avoid complications. 'Flare-up' of tumor activity may follow TKI interruption. However, it is not known if continuing TKIs during minimally invasive interventions is safe. We report here the first case in which an embolization of metastasis is performed without interrupting lenvatinib treatment. The procedure was successful and free of complications.

The experience of an Endocrinology Division on the use of tyrosine multikinase inhibitor therapy in patients with radioiodine-resistant differentiated thyroid cancer

PURPOSE

To describe the experience of our Division of Endocrinology with multikinase inhibitor (MKI) treatment in radioiodine-resistant differentiated thyroid cancer (DTC) patients.

METHODS

Adults patients with a diagnosis of DTC treated with an MKI drug from March 2011 to October 2018 were registered into a retrospective database. Primary objectives were: the assessment of progression-free survival (PFS) and radiographic response evaluated according to RECIST v. 1.1. Adverse events (AEs) were evaluated by using Common Terminology Criteria for Adverse Events v. 5.0.

RESULTS

Twenty-two patients were treated with MKIs (21 with sorafenib, one with lenvatinib as first-line treatment). Seven patients required a second-line therapy with lenvatinib and one patient required a third-line treatment with pazopanib. Median duration of treatment was 11.2 (4.8-79.6) months. Best responses with sorafenib were partial response (PR) in two patients (11%), stable disease (SD) >6 months in 13 patients (72%), and progressive disease (PD) in three patients (17%). Best responses with second-line lenvatinib were PR in one patient (33%) and SD in two patients (66%). Median PFS was 31.5 months. AEs were present in 19 (90%) patients under sorafenib. The most common AEs were hand-foot syndrome (HFS) (67%), diarrhea (52%), and hypertension (52%). Definitive withdrawal was necessary in only one patient (4.7%).

CONCLUSIONS

Our study reflects the real-world clinical experience of an Endocrinology Division on the management of radioiodine-resistant DTC patients with sorafenib and lenvatinib, showing a beneficial therapeutic effect with acceptable tolerability.

Sorafenib: key lessons from over 10 years of experience

Introduction: In 2005, sorafenib was the first targeted therapy approved for advanced renal cell carcinoma (RCC), transforming treatment. In hepatocellular carcinoma (HCC), for more than a decade, sorafenib remained the only approved systemic therapy to have demonstrated a survival benefit in first-line unresectable HCC. In 2013, sorafenib was the first targeted agent approved for patients with differentiated thyroid cancer (DTC) refractory to radioactive iodine treatment. Areas covered: This review discusses the development, advances, and challenges associated with sorafenib use in RCC, HCC, and DTC over the past decade. A search was performed on PubMed and key congresses as required, with no time limits. Expert commentary: Sorafenib has had a lasting impact on the therapeutic landscape of RCC, HCC, and DTC, and remains an important treatment option despite a rapidly evolving treatment landscape. Extensive clinical and real-world experience has been invaluable in improving patient management and maximizing benefit from treatment. Ongoing clinical trials continue to evaluate sorafenib in different settings, and in combination with other therapies in HCC and DTC. We have no doubt that sorafenib will continue to be an important treatment option in the coming years.

Differentiated thyroid cancer theranostics: radioiodine and beyond

The term theranostics is the combination of a diagnostic tool that helps to define the right therapeutic tool for specific disease. It signifies the "we know which sites require treatment (diagnostic scan) and confirm that those sites have been treated (post-therapy scan)" demonstrating the achievable tumor dose concept. This term was first used by John Funkhouser at the beginning of the 90s, at the same time the concept of personalized medicine appeared. In nuclear medicine, theranostics is easy to apply and understand because of an easy switch from diagnosis to therapy with the same vector. It helps in maximizing tumor dose and sparing normal tissue with high specific and rapid uptake in metastasis. The oldest application of this concept is radioactive iodine I-131 (RAI). The first treatment based on the theranostic concept was performed on thyroid cancer patients with RAI in 1946. From then on management of differentiated thyroid cancer (DTC) has evolved on the multimodality concept. We now use the term "our" patient instead of "my" patient to signify this. However, the initial surgical management followed by RAI as per the theranostics has remained the mainstay in achieving a cure in most of DTC patients. The normal thyroid cells metabolise iodine, the principle of which is utilized in imaging of the thyroid gland with isotopes of iodine. RAI treatment of DTC is based on the principle of sodium iodide symporter (NIS) expressing thyroid cells with DTC cells having the ability of trapping circulating RAI successfully helping in treatment of residual and metastatic disease. NIS is usually negative in poorly differentiated cells and is inversely proportional to Glucose transporter receptor Type 1 expression. Both positive and negative NIS are the key components of the theranostic approach in treatment of DTC. Presence or absence of NIS is documented by either whole body iodine scintigraphy (WBS) or 2-deoxy-2(18F) fludeoxyglucose (FDG) positron emission tomography computed tomography (PET-CT). Currently, single photon emission CT and CT (SPECT-CT) has significantly improved the precision and sensitivity of whole body iodine scintigraphy with its capability of accurate localization of disease foci whether iodine avid or non-avid. This has helped in a more personalized approach in treatment. This review will give an overview of the role of NIS in the theranostic approach to management with RAI, its current status and also the molecular approach to treatment in RAI refractory disease.

Navigating Systemic Therapy in Advanced Thyroid Carcinoma: From Standard of Care to Personalized Therapy and Beyond

Thyroid cancer, with the exception of anaplastic thyroid cancer, typically has very favorable outcomes with the standard therapy. However, those that persist, recur, or metastasize are associated with a worse prognosis. Targeted therapy with kinase inhibitors has shown promise in advanced cases of thyroid cancer, and currently five drug regimens are approved for use in clinical practice in the treatment of differentiated, medullary, and anaplastic thyroid cancer, with more options in the pipeline. However, one of the greatest dilemmas is when and how to initiate one of these drugs, and this is discussed herein.

Thyroglobulin "Nonsecretor" Metastatic Poorly Differentiated Thyroid Carcinoma with Noniodine Concentrating Disease and Aggressive Clinical Course: A Clinical Case Series

Poorly differentiated thyroid carcinomas (PDTC) are a subgroup of thyroid cancers with aggressive behavior and worse prognosis compared to the well DTC. Limited diagnostic tools and therapeutic options exist for such cases, and the appropriate management algorithm continues to evolve in this subgroup. They pose difficulty in clinical management due to their behavioral heterogeneity and increased occurrence of aggressive clinical behavior underlining the need for management individualization. In the present communication, a case series of three clinically challenging cases of PDTC (with low serum thyroglobulin (Tg) and iodine nonavidity) are presented with a discourse on their management intrigues, unresolved issues and the requirement of a distinctive management protocol. A small fraction of PDTCs may show low serum Tg values, with the questionable significance of its role for the assessment and monitoring of disease burden in this group of patients. Given uncommon occurrence, limited and variable literature data, management guidelines for “nonsecretor” PDTC needs to be more clearly defined based on scientific evidence. The present clinical case series of PDTC with low serum thyroglobulin in the context of noniodine concentrating metastatic disease and aggressive clinical course (”nonsecretor” status) was noteworthy from this viewpoint.

Long-term efficacy of lenvatinib for recurrent papillary thyroid carcinoma after multimodal treatment and management of complications: a case report

Background

The advent of tyrosine kinase inhibitors (TKIs) has changed the treatment of RAI refractory, unresectable recurrent differentiated thyroid cancer (DTC), which was formerly treated with multidisciplinary remedies.

Case presentation

Here we describe the case of a 64-year-old woman who underwent total thyroidectomy with tracheal resection and suffered from a recurrent tumor in the neck and multiple lung and bone metastases 3 and 11 months, respectively, after the operation. Multimodal therapies, RI (I-131), EBRT, and taxane-based chemotherapy were ineffective, and sorafenib was started as a TKI. However, because of disease progression, sorafenib was replaced by lenvatinib after 9 months. The effect of lenvatinib has continued for more than 1 year and 9 months, and the patient has well survived. During the treatment period, a tracheal pin-hole fistula suddenly emerged, which was naturally cured by the temporary cessation of lenvatinib. Adverse events such as hypertension, proteinuria, and diabetes as innate complications have been successfully managed until the present according to our institute regulations.

Conclusions

Even where multimodal treatment was ineffective, lenvatinib was suggested to be an alternative treatment option for RAI refractory recurrent DTC and patient could have a chance to be controlled successfully.

Treatment of refractory thyroid cancer

Distant metastases from thyroid cancer of follicular origin are uncommon. Treatment includes levothyroxine administration, focal treatment modalities with surgery, external radiation therapy and thermal ablation, and radioiodine in patients with uptake of ¹³¹I in their metastases. Two-thirds of distant metastases become refractory to radioiodine at some point, and when there is a significant tumor burden and documented progression on imaging, a treatment with a kinase inhibitor may provide benefits.

Radioiodine refractory differentiated thyroid cancer

Differentiated thyroid cancer (DTC) is usually curable with surgery, radioactive iodine (RAI), and thyroid-stimulating hormone (TSH) suppression. However, local recurrence and/or distant metastases occur in approximately 15% of cases during follow-up, and nearly two-thirds of these patients will become RAI-refractory (RR-DTC) with a poor prognosis. This review focuses on the most challenging and rapidly evolving aspects of RR-DTC, and we discuss the considerable improvement in more accurately defining RR-DTC, more effective therapeutic strategies, and describe the diagnosis, pathogenesis, and future prospects of RR-DTC. Along with the detection of serum thyroglobulin and anatomic imaging modalities, such as ultrasound and computer tomography, radionuclide molecular imaging plays a vital role in the evaluation of RR-DTC. In addition, continual progress has been made in the management of RR-DTC, including watchful waiting under appropriate TSH suppression, local treatment approaches, and systemic therapies (molecular targeted therapy, redifferentiation therapy, gene therapy, and cancer immunotherapy). These all hold promise to change the natural history of RR-DTC.

Advances in small molecule therapy for treating metastatic thyroid cancer

INTRODUCTION

Multi kinase inhibitors (MKIs) are new drugs, which show activity against receptors of different growth factors leading to the inhibition of tumor cells growth and proliferation. This review summarizes a 10-year experience with the use of MKIs in thyroid cancer (TC). It focuses not only on sorafenib, lenvatinib, vandetanib and cabozantinib, already approved in TC, but also presents an overview of the results of different trials with distinct MKIs so far carried out in TC. Areas covered: Published results of phase I, II and III studies and other reports evaluated the efficacy of different targeted drugs in TC. Expert opinion: Despite numerous clinical trials with distinct MKIs, only four of them unequivocally demonstrated a beneficial effect on progression free survival in radioiodine refractory differentiated or medullary TC. In contrast to other solid tumors, we are still lacking in convincing evidences of their impact on overall survival. We still do not have any strong proof fulfilling evidence-based medicine criteria, when to start MKIs and which drug to use. The questions whether we really have to wait for disease progression in patients with a large tumor burden and/or aggressive types TC or when to stop MKIs treatment remain open.

Updates on the Management of Advanced, Metastatic, and Radioiodine Refractory Differentiated Thyroid Cancer

Differentiated thyroid cancer (DTC) accounts for 95% of all thyroid cancers and is generally an indolent tumor, treated effectively with surgery, radioactive iodine, and thyroid-stimulating hormone suppressive therapy. However, 5-10% of patients have advanced disease, with aerodigestive tract invasion, distant metastases, or radioiodine refractory disease, with poor prognosis. This review focuses on the approaches for treating advanced DTC, including management of gross extra-thyroidal extension, recurrent loco-regional or distant metastatic disease, the role of external beam radiation therapy and systemic treatment. Locally ablative treatment modalities, including surgery, radiation therapy, and thermal ablation are evolving and can be used in selected patients. In recent years, new therapeutic agents with molecular targets have become available and two multi-kinase inhibitors, Sorafenib and Lenvatinib, have been licensed for iodine refractory DTC showing an advantage in terms of progression-free survival, although an impact on overall survival has not been proven yet. Management of advanced thyroid cancer can be challenging but a multidisciplinary approach can significantly improve outcomes for this patient population.