Lesion-Based Evaluation Predicts Treatment Response to Lenvatinib for Radioactive Iodine-Refractory Differentiated Thyroid Cancer: A Korean Multicenter Retrospective Study

Survival Predictors of Radioiodine-refractory Differentiated Thyroid Cancer Treated With Lenvatinib in Real Life

CONTEXT

Lenvatinib is approved for the treatment of radioiodine-refractory differentiated thyroid cancer (RR-DTC). The definition of predictive factors of survival is incomplete.

OBJECTIVE

To identify pre- and posttreatment survival predictors in a real-life cohort of RR-DTC treated with lenvatinib.

DESIGN

Multicenter, retrospective, cohort study.

SETTING

3 Italian thyroid cancer referral centers.

PARTICIPANTS

55 RR-DTC treated with lenvatinib.

MAIN OUTCOME MEASURES

Progression-free survival (PFS) and overall survival (OS).

RESULTS

Lenvatinib was the first-line kinase-inhibitor in 96.4% of subjects. Median follow-up was 48 months. Median PFS and OS were 26 [95% confidence interval (CI) 19.06-32.93] and 70 months (95% CI 36-111.99), respectively. Pretreatment setting: Eastern Cooperative Oncology Group (ECOG) performance status was independently related to PFS [P < .001; hazard ratio (HR) 18.82; 95% CI 3.65-97.08: score 0-1 as reference] and OS (P = .001; HR 6.20; 95% CI 2.11-18.20; score 0-1 as reference); radioactive iodine (RAI) avidity was independently related to PFS (P = .047; HR 3.74; 95% CI 1.01-13.76; avid disease as reference). Patients with good ECOG status (0-1) and RAI-avid disease obtained objective response in 100% of cases and achieved a median PFS of 45 months without any death upon a median follow-up of 81 months. Posttreatment setting: the best radiological response independently predicted PFS (P = .001; HR 4.6; 95% CI 1.89-11.18; partial/complete response as reference) and OS (P = .013; HR 2.94; 95% CI 1.25-6.89; partial/complete response as reference).

CONCLUSION

RR-DTC with good performance status and RAI-avid disease obtains the highest clinical benefit from lenvatinib. After treatment initiation, objective response was the only independent survival predictor.

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.

Can 99 Tc m -3PRGD 2 (α ν β 3 ) and 18 F-FDG dual-tracer molecular imaging change the therapeutic strategy for progressive refractory differentiated thyroid cancer: Case report

RATIONALE

The management of radioiodine refractory differentiated thyroid cancer (RAIR-DTC) represents a major challenge in thyroid cancer. The American Thyroid Association guidelines recommend the use of tyrosine kinase inhibitors (TKIs) for RAIR-DTC that does not respond to conventional treatment. Currently, imaging modalities that predict the response to TKI treatment based on morphological and functional features are lacking. we report a case of a patient with progressive RAIR lung metastases who underwent 2-deoxy-2-[ 18 F]fluoro-D-glucose and 99technetiumm-three polyethylene glycol spacers-arginine-glycine-aspartic acid ( 99 Tc m -3PRGD 2 ) dual-tracer imaging and investigate the value of this imaging strategy for determining subsequent therapeutic schedules.

PATIENT CONCERNS

A 52-year-old man with advanced RAIR-DTC and progressive lung metastasis. After TKI treatment [sorafenib] lost its clinical benefits, the patient's therapeutic response was evaluated as progressive disease. 2-deoxy-2-[ 18 F]fluoro-D-glucose PET/CT and 99 Tc m -3PRGD 2 SPECT/CT were performed. There were multiple FDG-positive lesions in the lung. However, 99 Tc m -3PRGD 2 SPECT/CT showed only 1 lesion in the right middle pulmonary lobe with arginine-glycine-aspartic positivity.

DIAGNOSIS

RAIR-DTC.

INTERVENTIONS

Radiofrequency ablation was performed for only the lesion with RDG and FDG positivity.

OUTCOMES

The patient quickly achieved partial response.

LESSONS

This case indicates that for progressive RAIR metastases, patients can benefit more from prioritizing treatment for lesions that are both arginine-glycine-aspartic and FDG positive.

The osteopontin expression and microvascular density in thyroid cancer, comparison of CT and ultrasound in diagnosis of thyroid cancer and correlations of CT features and thyroid cancer

BACKGROUND

The aim of this study was to explore the osteopontin expression and microvascular density in thyroid cancer, compare computed tomography (CT) and ultrasound in diagnosis of thyroid cancer and investigate the correlations of CT Features and thyroid cancer.

METHODS

A total of 80 patients with thyroid masses admitted to our hospital from April 2017 to August 2019 were selected, of which there were 40 with benign tumor and 40 with malignant tumor. All patients with thyroid cancer confirmed by pathological tissue biopsy were examined by ultrasound (ultrasound group) and CT (CT group). The expression of osteopontin was detected by PCR while microvascular density was tested by immunohistochemistry. Then univariate analysis and multivariate logistic regression analysis of risk factors were carried out for CT imaging diagnosis of thyroid cancer.

RESULTS

The levels of osteopontin and microvascular density in malignant group were significantly higher than those in benign group. The incidence rates of unclear boundary and peripheral lymph node enlargement in CT group were remarkably higher than those in ultrasound group. The diagnostic rate of masses ≥1 cm in diameter was notably higher than that of masses <1 cm in diameter in thyroid cancer patients in CT group and ultrasound group (P<0.05). In addition, the diagnostic rates of follicular carcinoma and papillary carcinoma were higher, whereas those of medullary carcinoma and undifferentiated carcinoma were lower in CT group and ultrasound group. There was no significant difference in the accuracy of thyroid cancer diagnosis between CT group and ultrasound group. Moreover, diameter ≥1 cm, irregular shape, unclear boundary, calcified foci, uneven density/echo and peripheral lymph node enlargement were related risk factors for the CT imaging diagnosis of thyroid cancer, in which irregular shape, unclear boundary, calcified foci and uneven density/echo were independent risk factors for the CT imaging diagnosis of thyroid cancer.

CONCLUSIONS

The levels of osteopontin and microvascular density were increased in thyroid cancer. CT examination may be of higher diagnostic value in diagnosis of thyroid cancer compared with ultrasound. Irregular shape, unclear boundary, calcified foci, and uneven density/echo were independent risk factors for the CT imaging diagnosis of thyroid cancer.

Daily Management of Patients on Multikinase Inhibitors’ Treatment

In a minority of differentiated thyroid cancer (TC) cases and in a large percentage of poorly differentiated TCs (PDTCs) and anaplastic TCs (ATCs), the prognosis is poor due to the lack of response to conventional treatments. In the last two decades, multikinase inhibitor (MKI) compounds have been developed and demonstrated to be very effective in these aggressive cases. Besides the great efficacy, several adverse events (AEs) have been reported in virtually all patients treated with MKIs, largely overlapping between different compounds and including hypertension, diarrhea, anorexia, decreased weight, fatigue, and proteinuria. Most grade 3–4 adverse reactions occur during the first 6 months of treatment and require dosage reduction and/or drug discontinuation. Due to severity of the AEs related to the treatment with MKIs, a multidisciplinary team is definitely required for the daily management of these patients, for the evaluation of the disease status, and the psychophysical condition. Moreover, it is crucial that the patients could have a facilitated access to reach either specialist doctors or nurses who must have been trained to follow them for their individual clinical complications. The follow-up visits should take place at monthly intervals until the sixth month and then every 1–2 months until the completion of the first year of treatment. The flow chart followed at our tertiary center is reported in the present review as a real-life-based example for the follow-up of patients with advanced TC on MKI treatment.

New approaches for patients with advanced radioiodine-refractory thyroid cancer

The cumulative evidence over the past decades has shown that the incidence of differentiated thyroid carcinoma (DTC) has exponentially increased. Approximately 10% of patients with DTC exhibit recurrent or metastatic disease, and about two-thirds of the latter will be defined as refractory to radioactive iodine (RAIR) treatment. Since this condition implies 10-year survival rates less than 10% after detection, using available treatments, such as systemic and targeted therapies, have become increasingly relevant. The initiation of these treatments aims to reach stabilization, tumor volume reduction, and/or symptom improvement and it should be decided by highly specialized endocrinologists/oncologists on the basis of patient's features. Considering that despite enlarged progression-free survival was proven, multikinase inhibitors remain non-curative, their benefits last for a limited time and the side effects potentially cause harm and quality of life reduction. In this context, molecular testing of cancer cells provides a promising spectrum of targeted therapies that offer increased compatibility with individual patient needs by improving efficacy, progression free survival, overall survival and adverse events profile. This review article aims to provide a summary of the current therapeutic strategies in advanced RAIR-DTC, including approved target therapies as well as those for off-label use, RAI resensitization agents, and immunotherapy.

Nephrotoxicity in advanced thyroid cancer treated with tyrosine kinase inhibitors: An update

Over the past decade, the prognosis of advanced thyroid cancer (TC) patients has dramatically improved thanks to the introduction of tyrosine kinase inhibitors (TKIs). Despite their effectiveness, these drugs are burdened with several side effects that can negatively affect quality of life and compromise therapy continuation. Among renal adverse events (RAEs), proteinuria is the most frequently reported in clinical trials and real-life experiences, especially during treatment with lenvatinib or cabozantinib. This peculiar toxicity is commonly associated with targeted therapies with anti-angiogenic activity, even if the mechanisms underlying its onset and progression are not entirely clear. RAEs should be early recognized and properly managed to avoid renal function worsening and life-threatening consequences. Aiming at providing a comprehensive summary that can help clinicians to identify and manage TKIs-related RAEs in TC patients, we reviewed the current evidence about this topic, from pathogenesis and potential risk factors to diagnosis and treatment.

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.

Prognostic factors in patients with advanced differentiated thyroid cancer treated with multikinase inhibitors - a single Brazilian center experience

OBJECTIVE

The aim of this study was to describe the real-world experience multikinase inhibitors (MKI) in the treatment advanced differentiated thyroid carcinoma (DTC) refractory to radioactive iodine (RAIR) therapy.

METHODS

We reviewed the records of all patients with MKI-treated DTC from 2010 to 2018. Progression free survival (PFS), response rates (RR) and adverse events (AE) profiles were assessed. Clinical parameters were compared between groups with different outcomes (disease progression and death) to identify possible prognostic factors and benefit from treatment.

RESULTS

Forty-four patients received MKI for progressive RAIR DTC. Median PFS was 24 months (10.2-37.7) and median overall survival (OS) was 31 months. Best overall response was complete response in one patient (4.5%), partial response in nine (20.4%), stable disease in twenty-two (50%), and progressive disease (PD) in twelve (27.3%). Seventy-two point 7 percent patients had clinical benefit and AE were mild in most cases (82.7%). Progressive patients were more likely to have FDG positive target lesion than those who did not progress (p = 0.033) and higher maximum SUV on target lesions (p = 0.042). Presence of lung-only metastasis and lower thyroglobulin (Tg) during treatment was associated with stable disease (p = 0.015 and 0,049, respectively). Patients with shorter survival had larger primary tumor size (p = 0.015) and higher maximum SUV on target lesions (p = 0.023).

CONCLUSION

Our findings demonstrate safety and effectiveness of MKI in patients with advanced RAIR DTC. We were able to identify as possible prognostic markers of better outcomes: absence of FDG uptake on target lesions, lower maximum SUV on PET-CT, presence of lung-only metastasis and lower Tg during treatment.

Low Dose of Lenvatinib Treatment for Patients of Radioiodine-Refractory Differentiated Thyroid Carcinoma - A Real-World Experience

Background

Lenvatinib treatment of 24 mg/day for radioiodine-refractory differentiated thyroid carcinoma (RRDTC) patients was almost intolerable, with high rates of dose reduction, interruption and discontinuation. Balancing treatment safety with disease risks remains challenging, and the appropriate dosage remains unclear in Asia.

Patients and Methods

A total of 65 RRDTC patients treated with lenvatinib were retrospectively collected from Oct. 2015 to Jun. 2020 from two medical centers of South Taiwan. The drug tolerability, treatment efficacy and clinical outcomes were analyzed.

Results

Different doses of lenvatinib were initiated but ultimately maintained with a median dose of 10 mg/day within the first 3 months. The disease control rate reached 89.2%, including 24.6% partial response and 64.6% stable disease. Disease progression occurred in 10.8% of patients and increased to 40.0% at the end. Eventually, the treatment dose achieved a median progression-free survival (PFS) of 26.1 months (95% CI: 17.1-NA) with overall survival (OS) not reached yet (24.1~NA). Overall, the 48-month PFS rate was 35.6% (95% CI: 18.5–68.4) and 48-month OS was 54.3% (95% CI: 41.2–71.7). The dose was tolerable with a dose reduction rate of 44.6%, dose interruption rate of 40.0% and fewer high-graded adverse events. The drug discontinuation rate was only 3.1%. However, RRDTC patients with bone metastasis or maximal dose exposure to RAI (≥600 mCi) may have less efficacy to the low maintenance dose treatment.

Conclusion

Assessing treatment intensity, safety and efficacy, low-dose lenvatinib treatment was well tolerated by RRDTC patients and displayed acceptable drug efficacy and outcomes.

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.

Predictors of Response and Survival to Multikinase Inhibitors in Radioiodine Resistant Differentiated Thyroid Cancer

Sorafenib and lenvatinib are the only multikinase inhibitors (MKIs) approved for the treatment of radioactive iodine refractory differentiated thyroid cancer (RR-DTC). Although they have been demonstrated to improve progression free survival and overall response rate, the risk of toxicities is very high, worsening patients’ quality of life. Therefore, predicting MKI treatment outcomes in the setting of RR-DTC is very challenging for optimizing patients’ management. The current review provides an overview of the predictive factors for the response and survival of sorafenib and lenvatinib in RR-DTC. In this setting, a systemic therapy should be considered after conducting a multidisciplinary discussion aimed at evaluating the risk-benefit ratio of the treatment and taking into account several clinical, biochemical, and molecular factors. Age, performance status, and cancer-related symptoms are the most important clinical markers to be considered prior to starting MKI treatment, together with tumor burden. Some tissue and circulating biomarkers have been investigated, those involved in the angiogenic pathways being the most promising. Finally, prospective clinical trials aimed at evaluating predictive markers for therapeutic response are needed for tailoring patient management and allowing more appropriate treatment choices.

A Joint Statement from the American Thyroid Association, the European Association of Nuclear Medicine, the European Thyroid Association, the Society of Nuclear Medicine and Molecular Imaging on Current Diagnostic and Theranostic Approaches in the Management of Thyroid Cancer

Background: The American Thyroid Association (ATA), the European Association of Nuclear Medicine, the European Thyroid Association, and the Society of Nuclear Medicine and Molecular Imaging have established an intersocietal working group to address the current controversies and evolving concepts in thyroid cancer management and therapy. The working group annually identifies topics that may significantly impact clinical practice and publishes expert opinion articles reflecting intersocietal collaboration, consensus, and suggestions for further research to address these important management issues. Summary: In 2019, the intersocietal working group identified the following topics for review and interdisciplinary discussion: (i) perioperative risk stratification, (ii) the role of diagnostic radioactive iodine (RAI) imaging in initial staging, and (iii) indicators of response to RAI therapy. Conclusions: The intersocietal working group agreed that (i) initial patient management decisions should be guided by perioperative risk stratification that should include the eighth edition American Joint Committee on Cancer staging system to predict disease specific mortality, the modified 2009 ATA risk stratification system to estimate structural disease recurrence, with judicious incorporation of molecular theranostics to further refine management recommendations; (ii) diagnostic RAI scanning in ATA intermediate risk patients should be utilized selectively rather than being considered mandatory or not necessary for all patients in this category; and (iii) a consistent semiquantitative reporting system should be used for response evaluations after RAI therapy until a reproducible and clinically practical quantitative system is validated.

Lenvatinib as first-line treatment for advanced thyroid cancer: long progression-free survival

PURPOSE

Lenvatinib (LEN) has been approved for the treatment of patients with progressive radioiodine-refractory differentiated thyroid cancer (RAI-R DTC). Real-life studies reported a lower progression-free survival (PFS) than the registration study, likely due to the more advanced stage of tumors, the more frequent pretreatment with other TKIs, the limited follow-up, and the worse clinical condition of the patients included.

METHODS

We evaluated the clinical data of our cohort of 13 consecutive patients, all receiving LEN as a first-line TKI treatment, and followed-up in a single tertiary Center.

RESULTS

All patients had an ECOG of 0-1 and regional or distant metastases were documented in 61.5% and 77% of patients, respectively. Median PFS was 22 months (95% CI 14-35) with partial response in 69% and stable disease in 31% of patients. All patients experienced at least one adverse event (AE), the most frequent being fatigue, anorexia, diarrhea, and hypertension. The daily dose was reduced in 70% of patients and only one patient (7.7%) discontinued the drug for AEs.

CONCLUSION

In this series of RAI-R DTC patients, with the unique features to have an ECOG 0 or 1 and to be naive for TKI treatments, PFS was the longest among all real-life published so far, with the highest rate of patients with partial response and one of the lowest drug discontinuation rate for AEs. The correct timing of treatment start, the tailoring of the dose, and a proper management of the AEs may have a significant impact on the treatment response to LEN.

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.

Unusual metastases from differentiated thyroid cancers: A multicenter study in Korea

Background

Although infrequent, distant metastasis from differentiated thyroid cancer is the main cause of mortality in patients and mostly involves the lung, bone, and brain. Distant metastases to other sites in differentiated thyroid cancer patients are rare, thus, the clinical course of unusual metastases has not been adequately researched. In the present study, the clinico-pathological findings and treatment outcomes of unusual metastases in differentiated thyroid cancer patients in Korea were evaluated.

Patients and methods

We retrospectively reviewed the medical records of differentiated thyroid cancer patients with unusual metastases in four Korean tertiary hospitals (Chonnam National University Hwasun Hospital, Asan Medical Center, Busan National University Hospital, Severance Hospital). Unusual metastases were diagnosed using (1) cytology or histology and/or (2) imaging studies including fluorodeoxyglucose F 18 positron emission tomography/computed tomography and/or iodine 131 whole body scans with simultaneously elevated serum levels of thyroglobulin. The pathological findings of primary thyroid cancer, diagnostic method for unusual metastases, and treatment responses of unusual metastases were examined.

Results

In all, 25 unusual metastatic foci of 19 patients were analyzed; 13 patients (68.4%) had papillary thyroid carcinoma including 4 follicular variant papillary thyroid carcinomas. The median time interval between the first diagnosis of primary thyroid cancer and unusual metastases diagnosis was 110 months (11.0–138.0 months). Only 4 patients (21.1%) had synchronous unusual metastases and 6 patients (31.6%) were symptomatic. Unusual metastases included 19 metastases to solid organs (6 to kidney, 5 to liver, 4 to pancreas, 3 to adrenal gland, and 1 to ovary) and 6 to the skin and muscles. Unusual metastases were pathologically proven in 10 patients (52.6%) and 11 of 16 patients (68.8%) who received iodine 131 whole body scans had radioiodine-refractory differentiated thyroid cancer. Among 5 patients treated with tyrosine kinase inhibitors, 4 treated with lenvatinib showed stable disease or a partial response at the first treatment response. Six patients (31.6%) died due to disease progression during the median 20.0-month follow-up period (11.0–55.0 months).

Conclusion

Unusual metastases from differentiated thyroid cancer are thought to be underestimated due to disease rarity and their metachronous nature with other distant metastases. The most of unusual metastases in differentiated thyroid cancer patients are existed with usual distant metastasis and clinical outcomes of those could not be significantly different from the prognosis of usual distant metastasis.

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.

Role of [99mTc]Tc-Galacto-RGD2 SPECT/CT in identifying metastatic differentiated thyroid carcinoma after thyroidectomy and radioactive iodine therapy

PURPOSE

Integrin αvβ3, a member of the arginine-glycine-aspartate (RGD)-binding subfamily, is associated with tumor angiogenesis and metastasis. The aim of study is to investigate the clinical role of [^99mTc]Tc-Galacto-RGD₂ SPECT/CT in high-risk differentiated thyroid carcinoma (DTC) after thyroidectomy and radioactive iodine (RAI) therapy.

METHODS

Thirty-six patients with high-risk DTC (20 males, 16 females; mean age: 59.9 ± 16.6 y) who underwent thyroidectomy and RAI therapy were consecutively enrolled in this study. All patients underwent [^99mTc]Tc-Galacto-RGD₂ SPECT/CT and diagnostic ¹³¹I whole-body scan 6 months after the last RAI treatment. A region of interest (ROI) was drawn and the ratio of tumor/non-target (T/NT) was calculated. Per-patient and per-lesion analysis was performed to evaluate the diagnostic efficacy. The final diagnosis was confirmed by histopathology and follow-up. Integrin αvβ3, CD31, and Ki-67 expression in the tumor were also analyzed for evaluation of angiogenesis and proliferation.

RESULTS

Out of 36 patients, twenty-two had metastatic disease. By per-patient analysis, the area under the curve of [^99mTc]Tc-Galacto-RGD₂ SPECT/CT was marginally significantly higher than that of ¹³¹I whole-body scan and morphological imaging (P = 0.0034 and 0.0006). For per-lesion analysis, [^99mTc]Tc-Galacto-RGD₂ SPECT/CT identified 67 metastatic lymph nodes in 14 patients, 12 lung metastases in four patients, and 12 bone metastases in six patients; its sensitivity was significantly higher than that of ¹³¹I whole-body scan in detection of lymphatic (90.54% vs. 55.41%, P = 0.0124) and bone metastasis (92.31% vs. 30.77%, P = 0.046). The ratio of T/NT in metastatic lesions increased with the DTC upstaging.

CONCLUSIONS

[^99mTc]Tc-Galacto-RGD₂ SPECT/CT has high sensitivity in the detection of metastasis in high-risk DTC and further contributes to evaluation of tumor angiogenesis and radio‑iodine refractory status.