Tertiary Care Experience of Sorafenib in the Treatment of Progressive Radioiodine-Refractory Differentiated Thyroid Carcinoma: A Korean Multicenter Study

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.

Prognostic Roles of Inflammatory Biomarkers in Radioiodine-Refractory Thyroid Cancer Treated with Lenvatinib

BACKGRUOUND

Inflammatory biomarkers, such as the neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), and platelet-to-lymphocyte ratio (PLR), serve as valuable prognostic indicators in various cancers. This multicenter, retrospective cohort study assessed the treatment outcomes of lenvatinib in 71 patients with radioactive iodine (RAI)-refractory thyroid cancer, considering the baseline inflammatory biomarkers.

METHODS

This study retrospectively included patients from five tertiary hospitals in Korea whose complete blood counts were available before lenvatinib treatment. Progression-free survival (PFS) and overall survival (OS) were evaluated based on the median value of inflammatory biomarkers.

RESULTS

No significant differences in baseline characteristics were observed among patients grouped according to the inflammatory biomarkers, except for older patients with a higher-than-median NLR (≥2) compared to their counterparts with a lower NLR (P= 0.01). Patients with a higher-than-median NLR had significantly shorter PFS (P=0.02) and OS (P=0.017) than those with a lower NLR. In multivariate analysis, a higher-than-median NLR was significantly associated with poor OS (hazard ratio, 3.0; 95% confidence interval, 1.24 to 7.29; P=0.015). However, neither the LMR nor the PLR was associated with PFS. A higher-than-median LMR (≥3.9) was significantly associated with prolonged OS compared to a lower LMR (P=0.036). In contrast, a higher-than-median PLR (≥142.1) was associated with shorter OS compared to a lower PLR (P=0.039).

CONCLUSION

Baseline inflammatory biomarkers can serve as predictive indicators of PFS and OS in patients with RAI-refractory thyroid cancer treated with lenvatinib.

Electrolyte disorders induced by six multikinase inhibitors therapy for renal cell carcinoma: a large-scale pharmacovigilance analysis

To provide evidence for optimization of multi-kinase inhibitors (MKIs) use in the clinic, we use the public database to describe and evaluate electrolyte disorders (EDs) related to various MKIs treated for renal cell carcinoma. We analyzed spontaneous reports submitted to the Food and Drug Administration Adverse Events Reporting System (FAERS) in an observational and retrospective manner. Selecting electrolyte disorders' adverse events to multikinase inhibitors (axitinib, cabozantinib, lenvatinib, pazopanib, sunitinib, and sorafenib). We used Reporting Odds Ratio (ROR), Proportional Reporting Ratio (PRR), Bayesian Confidence Propagation Neural Network (BCPNN), and multi-item gamma Poisson shrinker (MGPS) algorithms to analyze suspected adverse reactions of electrolyte disorders induced by MKIs (which were treated for renal cell carcinoma) between January 2004 and December 2022. As of December 2022, 2772 MKIs (which were treated for renal cell carcinoma) ICSRs were related to electrolyte disorders AEs. In general, there were more AEs cases in males, except lenvatinib and 71.8% of the cases were submitted from North America. ICSRs in this study, the age group most frequently affected by electrolyte disorders AEs was individuals aged 45-64 years for axitinib, cabozantinib, pazopanib, and sunitinib, whereas electrolyte disorders AEs were more common in older patients (65-74 years) for sorafenib and lenvatinib. For all EDs documented in ICSRs (excluding missing data), the most common adverse outcome was hospitalization(1429/2674, 53.4%), and the most serious outcome was death/life-threat(281/2674, 10.5%). The prevalence of mortality was highest for sunitinib-related EDs (145/616, 23.5%), excluding missing data (n = 68), followed by cabozantinib-related EDs (20/237, 8.4%), excluding missing data (n = 1). The distribution of time-to-onset of Each drug-related ICSRs was not all the same, and the difference was statistically significant (P = 0.001). With the criteria of ROR, the six MKIs were all significantly associated with electrolyte disorders AEs, the strongest association was the association between cabozantinib and hypermagnesaemia. MKIs have been reported to have significant electrolyte disorders AEs. Patients and physicians need to recognize and monitor these potentially fatal adverse events.

The efficacy and safety in radioactive iodine refractory thyroid cancer patients treated with sorafenib

Background

Sorafenib included in Chinese medical insurance is the earliest targeted drug for radioactive iodine refractory differentiated thyroid cancer (RR-DTC). This study is to further demonstrate the clinical efficacy and safety of sorafenib used in Zhujiang Hospital of Southern Medical University.

Methods

RR-DTC patients treated at our Department of Nuclear Medicine in Zhujiang Hospital of Southern Medical University (October 2017-May 2020) were retrospectively analyzed. Treatment effects, progression-free survival (PFS), and adverse effects (AEs) during medication were evaluated.

Results

Of the 31 patients included, 26 patients were evaluated for efficacy with a median follow-up time of 17.5 months (4.0-51.0 months). The disease control rate (DCR) was 57.7% (n = 15) and the objective response rate (ORR) was 26.9% (n = 7). Most patients with disease control had thyroglobulin decreases of more than 60% (p = 0.004), ORRs were favorable in patients with lung metastasis and lung-only metastasis (p = 0.010 and 0.001, respectively). The PFS of the 26 patients analyzed was 16.5 months (95%CI: 14.41 -23.90 months). In the subgroup analysis, female, patients with lung-only metastasis, hand-foot skin syndrome (HFS), and thyroglobulin response ≥ 60% observed longer PFS (p = 0.038, 0.045, 0.035, and 0.000, respectively), while patients with bone metastasis had lower PFS (p = 0.035). The most common toxicity profile was HFS (93.5%), followed by diarrhea (83.9%), alopecia (74.2%). All the side effects were mainly grade 1-2. Grade 3-4 adverse reactions were more common in diarrhea and HFS.

Conclusions

Sorafenib has promising efficacy in RR-DTC, especially in patients with lung metastasis and lung-only metastasis. The AEs of sorafenib were generally mild, and the main AE was HFS.

Psychiatric adverse reactions to non-selective RET multi-kinase inhibitors: a large-scale pharmacovigilance analysis

Objective: The development of non-selective multi-kinase inhibitors (MKIs) has improved the. survival outcomes of patients with cancers. Psychiatric disorders represent an MKIs related AE of particular concern, as they are often ignored and may harm the patient's personal and social functioning. Therefore, we use the public database to describe and evaluate psychiatric adverse events related to various non-selective RET MKIs. Provide evidence for optimizing drug administration in the clinic. Methods: We analyzed spontaneous reports submitted to the Food and Drug Administration Adverse Events Reporting System FDA Adverse Event Reporting System in an observational and retrospective manner. Selecting psychiatric AEs to non-selective RET multikinase inhibitors (sorafenib, lenvatinib, vandetanib, cabozantinib, and sunitinib). We used Reporting Odds Ratio (ROR), Proportional Reporting Ratio (PRR), Bayesian Confidence Propagation Neural Network (BCPNN), and multi-item gamma Poisson shrinker (MGPS) algorithms to analyze suspected adverse reactions of psychiatric related induced by non-selective RET MKIs between January 2004 and September 2022. Results: As of September 2022, 1,108 non-selective RET MKIs ICSRs were related to psychiatric AEs. 706 were ADR ICSRs, and 402 were non-ADR ICSRs. There were more ADR cases in males (69.5%), and 71.8% of the cases were submitted from North America. The age group most frequently affected by psychiatric ADRs was individuals aged 50-64 years for sorafenib, whereas 65-74 years for sunitinib, cabozantinib, and lenvatinib. In all psychiatric ADRs ICSRs, excluding missing data (n = 329), the most common adverse outcome was hospitalization (260/377, 69.0%), and the most serious was death (100/377, 26.5%). What calls for special attention is that the percentage of death rate for sunitinib was highest (24/54, 44.4%) in sunitinib-related psychiatric ADRs ICSRs, (excluding missing data, n = 44), followed by lenvatinib (4/14, 28.6%). Based on ROR, PRR, BCPNN, and MGPS methods, sorafenib, sunitinib, cabozantinib, and lenvatinib are significantly associated with all ADRs, the strongest association was the association between cabozantinib and feeding disorder. Conclusion: Despite the limitations, our study found that, except for vandetanib, other four drugs have been reported to have significant psychiatric side effects. Clinicians need to recognize and monitor these potentially fatal adverse events. If it is suitable for treatment with vandetanib, doctors should choose vandetanib for treatment.

Inflammatory biomarkers predict outcomes of patients with radioactive iodine refractory thyroid cancer treated with sorafenib

BACKGROUND

The objective of this multicenter, retrospective cohort study was to evaluate the ability of inflammatory biomarkers representing the host immune system to predict outcomes in 70 patients with progressive radioactive iodine (RAI)-refractory thyroid cancer who were treated with sorafenib.

METHOD

Patients were divided into low and high inflammatory biomarker groups based on median values. Progression-free survival (PFS) and overall survival (OS) were assessed based on the lymphocyte-to-monocyte ratio (LMR), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR).

RESULTS

The median LMR, NLR, and PLR values were 3.4, 2.2, and 140.1, respectively. No significant differences were observed in baseline characteristics of high and low LMR, NLR and PLR groups. Median PFS values were 6.6 and 19.5 months in the low and high LMR groups, respectively (P < 0.001). Compared with the high NLR and PLR groups, PFS was significantly prolonged in the low NLR and PLR groups (P = 0.003 and P = 0.041 respectively). In the multivariate analysis, low LMR and high NLR were associated with poor PFS after adjusting for multiple confounding factors including age, sex, pathology, disease-related symptoms, serum thyroglobulin level, lung-only metastasis, cumulative RAI dose, time from diagnosis, and longer diameter of the target lesion (hazard ratio, HR = 2.42; 95% confidence interval, CI 1.25-4.71; P = 0.009, and HR = 2.09; CI, 1.06-4.14; P = 0.033, respectively). High LMR, low NLR, and low PLR were significantly associated with prolonged OS (P = 0.011, P = 0.023, and P = 0.007, respectively). Patients with at least one risk factors for inflammatory biomarkers presented a significantly lower PFS (HR 2.29; CI, 1.36-3.84; P = 0.003) and OS (HR 2.95; CI, 1.49-5.81; P = 0.006) than patients without any risk factor.

CONCLUSION

Baseline inflammatory biomarkers successfully predicted PFS and OS in patients with progressive RAI-refractory thyroid cancer treated with sorafenib. These prognostic biomarkers might help arrive at appropriate clinical decisions regarding the use of sorafenib.

Lenvatinib Compared with Sorafenib as a First-Line Treatment for Radioactive Iodine-Refractory, Progressive, Differentiated Thyroid Carcinoma: Real-World Outcomes in a Multicenter Retrospective Cohort Study

Background: Sorafenib and lenvatinib have been widely adopted to treat radioactive iodine (RAI)-refractory differentiated thyroid carcinoma (DTC). However, limited data exist regarding a direct comparison of these tyrosine kinase inhibitors (TKIs). We aimed to evaluate the clinical efficacy and safety of two TKIs as first-line therapy in patients with distant metastatic or locally advanced, progressive, RAI-refractory DTC in real-world practice. Methods: In this multicenter, retrospective cohort study, we evaluated 136 patients with progressive distant metastatic or locally advanced, progressive, RAI-refractory DTC or poorly differentiated thyroid carcinoma (PDTC) who received first-line sorafenib or lenvatinib treatment. The primary outcome was progression-free survival (PFS). We also evaluated the objective response rate, disease-control rate, clinical benefit rate, and safety. Results: The median age of the patients was 68 years, and 35% (47/136) were male. Eighty and fifty-six patients were included in the sorafenib and lenvatinib groups, respectively. The median PFS was 13.3 months [95% confidence interval, CI, 9.9-18.1 months] in the sorafenib group and 35.3 months [CI, 18.2 months to upper limit not reported as the median was not reached] in the lenvatinib group (p = 0.001). A significantly prolonged PFS was observed in the lenvatinib group (compared with the sorafenib group) after adjusting for age, sex, pathology, disease-related symptom, lung-only metastasis, cumulative RAI dose, time from diagnosis, treatment duration, and longest diameter of the target lesion (hazard ratio = 0.34, CI, 0.19-0.60, p < 0.001). The partial response rate was 24% and 59% in the sorafenib and lenvatinib groups, respectively (p < 0.001). More common grade 3-4 adverse events were hypertension (16%, 9/56 vs. 1%, 1/80, p = 0.002) and proteinuria (32%, 18/56 vs. 0%, p < 0.001) in the lenvatinib group, and hand-foot skin reaction (24%, 19/80 vs. 4%, 2/56, p = 0.001) in the sorafenib group. Conclusion: In our study of Asian patients, first-line lenvatinib treatment of metastatic or locally advanced, progressive, RAI-refractory DTC or PDTC was associated with a longer PFS compared with sorafenib. However, severe hypertension and proteinuria were observed more frequently after lenvatinib treatment than after sorafenib treatment.

Use of multikinase inhibitors/lenvatinib concomitant with locoregional therapies for the treatment of radioiodine-refractory differentiated thyroid cancer

Locoregional recurrence of differentiated thyroid cancer (DTC) occurs in 20% of thyroid cancer patients. Currently, there are many strategies for management of locoregional recurrence of DTC that lead to local control of the disease. The introduction of lenvatinib into the therapeutic armamentarium provides a new option for the treatment of radioiodine-refractory DTC (RR-DTC). However, results for simultaneous treatment with lenvatinib and locoregional therapies are unknown in patients with RR-DTC. This paper reviews the current status of this approach and gives recommendations on the management of lenvatinib during concomitant locoregional procedures.

Molecular diagnosis and targeted treatment of advanced follicular cell-derived thyroid cancer in the precision medicine era

Most malignant thyroid tumours are initially treated with surgery or a combination of surgery and radioactive iodine (RAI) therapy. However, in patients with metastatic disease, many tumours become refractory to RAI, and these patients require alternative treatments, such as locoregional therapies and/or systemic treatment with multikinase inhibitors. Improvements in our understanding of the genetic alterations that occur in thyroid cancer have led to the discovery of several targeted therapies with clinical efficacy. These alterations include NTRK (neurotrophic tyrosine receptor kinase) gene fusions, with the tropomyosin receptor kinase inhibitors larotrectinib and entrectinib both approved by the European Medicines Agency and in other markets worldwide. Inhibitors of aberrant proteins resulting from alterations in RET (rearranged during transfection) and BRAF (B-Raf proto-oncogene) have also shown promising efficacy, and so far have received approval by the US Food and Drug Administration. Selpercatinib, a RET kinase inhibitor, was approved for use in Europe in early 2021. With the discovery of multiple actionable targets, it is imperative that effective testing strategies for these genetic alterations are integrated into the diagnostic armamentarium to ensure that patients who could potentially benefit from targeted treatments are identified. In this review, we offer our recommendations on the optimal testing strategies for detecting genetic alterations in thyroid cancer that have the potential to be targeted by molecular therapy. We also discuss the future of treatments for thyroid cancers, including the use of immune checkpoint inhibitors, and new generations of targeted treatments that are being developed to counter acquired tumour resistance.

Audit of Demographics, Treatment Patterns and Outcomes of Differentiated Thyroid Cancers Treated with Tyrosine Kinase Inhibitors

The real-world patterns of TKI use in differentiated thyroid cancer (DTC) are largely governed by the accessibility and financial feasibility of the patient with more sorafenib use compared to lenvatinib. There are limited data available on the toxicity profile, safety and tolerance of sorafenib and lenvatinib in DTC. Hence, we audited our practice on DTC. This is a retrospective single-centre analysis of patients with DTC who were referred to the Department of Medical Oncology for systemic therapy. Baseline demographics (age, sex, ECOG PS, comorbidities, substance use), tumour details (site of metastasis), previous treatment details, clinical features at metastasis (symptoms), the pattern of treatment, adverse events and outcomes including progression and death were extracted. There were 67 patients with DTC referred for systemic therapy; the median age was 56 (33-81) with a male preponderance (55.6%). The most common reason to start TKI therapy was radioactive iodine (RAI) cumulative dose > 600 milliCurie, followed by low iodine uptake in the RAI low-dose scan done at progression. The most common TKI used in the first line was sorafenib in 56 (83.6%) patients followed by lenvatinib in 9 (13.4%) patients. Papillary thyroid carcinoma was the most common histology (51, 76.1%), and the rest were follicular carcinoma (16, 23.9%). With a median follow-up of 36 months, the median PFS was 13.2 months (95% CI 10.4-16.0). The median OS was 18.8 months (95% CI 10.0-27.6). Among variables tested, no factors had a significant impact on the PFS or OS. The most common adverse events were hand-foot syndrome (54, 80.5%), diarrhoea (23, 33.3%) and transaminitis (24, 34.4%). The pattern of care of patients with RAI-refractory DTC is TKI therapy, especially sorafenib and lenvatinib in the real-world settings with comparable efficacy and safety profile compared to international literature.

Initial or salvage treatment with apatinib shows promise against radioiodine-refractory differentiated thyroid carcinoma

OBJECTIVE

Sorafenib and lenvatinib have been recommended as standard tyrosine kinase inhibitors (TKIs) for progressive radioiodine-refractory differentiated thyroid carcinoma (RR-DTC). However, their efficacy remains limited with unresolved drug resistance. Therefore, we conceived this open-label study based on real-world evidence to investigate the efficacy and safety of apatinib in patients with progressive RR-DTC.

METHODS

Off-label use of apatinib as either initial treatment or salvage treatment for sorafenib resistance was investigated. The primary endpoint was progression-free survival (PFS) and the secondary endpoints included objective response rate (ORR), overall survival (OS), and safety.

RESULTS

For all 28 enrolled patients, the median PFS was 15.1 months, with an ORR of 69.6%. The median OS was not reached at the data cut-off. In detail, the median PFS of 17.3 months and the ORR of 75% were determined in patients with TKI-naive RR-DTC (initial treatment group, n = 14). And, in patients with first-line sorafenib-resistant RR-DTC (salvage treatment group, n = 14), a median PFS of 12.0 months was reached, with an ORR of 45.5%. In the salvage treatment group, the median OS from the start of apatinib administration was 20.6 months, reaching 89.1 months from sorafenib treatment initiation. Adverse events at grade 3 or higher occurred in 64.3% of all subjects treated with apatinib.

CONCLUSIONS

This study demonstrated that apatinib shows promise against RR-DTC with tolerable toxicity, representing a novel initial treatment for progressive RR-DTC and effective salvage treatment for RR-DTC resistant to sorafenib.

Real-world insights into the efficacy and safety of tyrosine kinase inhibitors against thyroid cancers

Based on clinical trials demonstrating favorable short-term efficacy and tolerable toxicity, several tyrosine kinase inhibitors have been approved for treating locally recurrent or metastatic, progressive radioiodine-refractory differentiated thyroid cancer, BRAF^V600E-mutant anaplastic thyroid cancer, and advanced or progressive medullary thyroid cancer. Longer term efficacy and safety of these treatments have been investigated in multiple real-world studies, demonstrating indispensable complementary value. Hereby, we summarize data from a total of 27 real-world studies with a focus on long-term survival data and rare but life-threatening adverse effects. An overall picture of current real-world study was drawn, and integrated experience of multiple centers would be helpful to clinical practice and further research.

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.

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.

Prognostic Value of Lymphocyte-to-Monocyte Ratio for Japanese Patients With Differentiated Thyroid Cancer Treated With Sorafenib Therapy

BACKGROUND/AIM

We investigated the efficacy and safety of sorafenib in Japanese patients and the prognostic value of systemic immunity markers for predicting clinical outcomes after sorafenib therapy in patients with radioiodine refractory differentiated thyroid cancer (RR-DTC).

PATIENTS AND METHODS

We retrospectively evaluated 26 patients with RR-DTC who underwent sorafenib therapy between July 2014 and December 2020. The systemic immunity markers were calculated from blood cell counts.

RESULTS

The median overall survival (OS) was 2,002 days, and the clinical benefit rate was 80.8%. The high lymphocyte-to-monocyte ratio (LMR) group had significantly longer OS than the low LMR group (hazard ratio=0.21; 95% confidence interval=005-0.88; log-rank p=0.019). Adverse events observed in this study were acceptable, and no new safety signals associated with sorafenib were found.

CONCLUSION

Sorafenib therapy is efficacious and safe for Japanese patients with RR-DTC, and baseline LMR may be useful as a sorafenib therapy prognostic marker.

Multikinase inhibitors for the treatment of radioiodine refractory thyroid cancer: what have we learned from the 'real-world' experience?

PURPOSE OF REVIEW

Several molecularly targeted drugs for treating radioiodine resistant differentiated thyroid carcinomas (RAIR-DTC) have been identified. Among these, sorafenib and lenvatinib have been approved for clinical use in many countries. The present review will analyze efficacy and safety 'real-world' data (RWD) emerging after their commercialization.

RECENT FINDINGS

RWDs confirmed sorafenib and lenvatinib efficacy in terms of progression-free survival and, perhaps, overall survival improvement in patients with RAIR-DTC. Lenvatinib performance in RWDs appeared somehow lower than in randomized clinical trials (RCT), probably because the decision to start treatment in 'real life' was made when patients were in worse clinical conditions than in RCTs. Concerning safety, RWD studies corroborated RCT evidence of elevated overall and serious adverse event incidence. Notably, adverse events were manageable in most cases with appropriate treatment or dose reduction/interruption, so that the need for definitive withdrawal was limited. The suitability of multikinase inhibitors (MKI) as salvage therapy in RAIR-DTCs was also confirmed by RWD experience, at least for lenvatinib in the second-line setting.

SUMMARY

RWD analysis has corroborated RCT results in terms of MKI efficacy for both first-line and salvage treatment in patients with RAIR-DTC. The safety profiles emerging from RWDs seem to justify the caution recommended by most scientific guidelines.

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.

An International Phase 2 Study of Pazopanib in Progressive and Metastatic Thyroglobulin Antibody Negative Radioactive Iodine Refractory Differentiated Thyroid Cancer

Introduction: Multikinase inhibitors have clinical activity in radioactive iodine refractory (RAIR) differentiated thyroid cancers (DTCs) but are not curative; optimal management and salvage therapies remain unclear. This study assessed clinical effects of pazopanib therapy in RAIR-DTC patients with progressive disease, examining in parallel biomarker that might forecast/precede therapeutic response. Methods: Assessment of responses and toxicities and of any association between thyroglobulin (Tg) changes cycle 1 and RECIST (response evaluation criteria in solid tumors) response to pazopanib therapy were prospectively undertaken in Tg antibody negative RAIR-DTC patients. RECIST progressive metastatic disease <6 months preceding enrollment was required. With a sample size of 68 (assuming 23 attaining partial response [PR]), there would be 90% chance of detecting a difference of >30% when the proportion of patients attaining PR whose Tg values decrease by >50% is >50% cycle 1 (one-sided α = 0.10, two sample test of proportions). Mean corpuscular volume (MCV) change or mutational status or pretreatment were also explored as early correlates of eventual RECIST response. Results: From 2009 to 2011, 60 individuals were treated and evaluated; (one additional patient withdrew; another was found ineligible before therapy initiation); 91.7% had previous systemic therapy beyond RAI. Adverse events included one death (thromboembolic) deemed possibly pazopanib associated. Twenty-two confirmed RECIST PRs resulted (36.7%, confidence interval; CI [24.6-50.1]); mean administered 4-week cycles was 10. Among 44 fully accessible patients, the Tg nadir was greater among the 20 attaining PR (median: -86.8%; interquartile range [IQR]: -90.7% to -70.9%) compared with the 28 who did not (median: -69.0%; IQR: -78.1% to -27.7%, Wilcoxon rank-sum test: p = 0.002). However, the difference in the proportion of PRs among those whose Tg fell ≥50% after cycle 1 versus those that did not were not significantly correlated (-23.5% [CI: -55.3 to 8.3]; Fisher's exact test p-value = 0.27). RECIST response was also not correlated with/predicted by early MCV change, receipt of prior therapy, or tumor mutational status. Conclusions: This trial prospectively confirmed pazopanib to have clinical activity and manageable toxicities in patients with progressive RAIR-DTC. Response to pazopanib, however, was not robustly forecast by early associated changes in Tg or MCV, by prior therapy, or by tumor mutational status. ClinicalTrials.gov NCT00625846.

Experience of sorafenib treatment in differentiated thyroid cancer from Taiwan

BACKGROUND

Sorafenib has been shown to prolong the progression free survival (PFS) of advanced radioiodine (RAI) refractory differentiated thyroid cancer (DTC) and has been approved by the FDA as the result of the phase III DECISION trial. Sorafenib has been reimbursed for the treatment of RAI refractory DTC in Taiwan since Jan 2017. High percentage of adverse events (AE) was noted in DECISION trial. We conducted a study to show the real-world experience of sorafenib in Taiwan.

METHODS

We retrospectively collected the clinical data, including dose, AE, and PFS of sorafenib, of the DTC patients who received sorafenib treatment in National Cheng Kung University Hospital and China Medical University Hospital by chart review from 2012 to 2018.

RESULTS

Thirty-six advanced DTC patients with progression were included in this study. The starting dose of sorafenib in most patients was 200 mg twice daily and the mean daily maintenance dose was 433 mg. Five patients had partial response (13.9%) and 28 patients had stable disease (77.8%). The median PFS was 17.3 months (95% confidence interval: 11.9-33.6 months). Daily maintenance dose ≥ 600 mg was associated with better PFS (median PFS, not reached). The most common toxicity of sorafenib was hand foot skin reaction (69%), followed by diarrhea (42%), and skin rash (33%). Most of the toxicities were grade I/II.

CONCLUSION

Higher maintenance dose of sorafenib is associated with longer PFS while starting from half dose is feasible to minimize the incidence of high grade toxicities in the real-world use of sorafenib.

Lenvatinib for Radioactive Iodine-Refractory Differentiated Thyroid Carcinoma and Candidate Biomarkers Associated with Survival: A Multicenter Study in Korea

Background: Lenvatinib, an oral multikinase inhibitor, is the latest addition to the treatment options for radioactive iodine (RAI)-refractory progressive differentiated thyroid carcinoma (DTC). This study investigated the efficacy of lenvatinib in real-world practice and prognostic biomarkers of survival. Methods: This multicenter study included 43 patients receiving lenvatinib as first-line or second-line treatment after sorafenib for RAI-refractory DTC. Progression-free survival (PFS) was evaluated according to various clinical factors including thyroglobulin doubling time (TgDT), tumor volume DT (TVDT), and tumor growth slope (TGS; slope of tumor change rate). Results: Patients were treated with lenvatinib for a median of 14 months; 32 were previously treated with sorafenib. The median follow-up from lenvatinib initiation to the last censoring or death was 16 months. The median starting dose of 20 mg was reduced to a median sustainable dose of 10 mg in accordance with patient adverse events (AEs). The median PFS was 21.8 months; the median overall survival was not reached. The disease control rate was 97.7%, with the first objective response at 3.8 months. PFS was not significantly associated with previous sorafenib treatment, metastatic sites, or sustainable dose. TGS measured before (TGS_pre, p = 0.003) and after (TGS_post, p = 0.036) the initiation of lenvatinib was associated with PFS. The sum of the largest diameters of target lesions (p = 0.043) and TgDT (p = 0.024) were associated with PFS, but TVDT calculated before (TVDT_pre, p = 0.923) or after (TVDT_post, p = 0.966) lenvatinib treatment did not impact PFS. Lenvatinib was withdrawn in 24 patients (55.8%): in 6 patients because of treatment-induced AEs and in 18 patients because of disease progression or poor performance status. AEs of any grade were reported in all patients, and grade 3-4 AEs in 23.2% of the patients. The most frequent AE was fatigue or asthenia. Conclusions: Our results indicate that reduced doses of lenvatinib triggered by emergent AEs did not abrogate its apparent efficacy in patients with RAI-refractory DTCs. Rather, the sustained use of reduced doses of lenvatinib with a low rate of severe AEs may have contributed to the favorable outcomes. TgDT and TGS can assist in predicting the outcomes in these patients.

Sorafenib and radioiodine-refractory differentiated thyroid cancer (RR-DTC): a systematic review and meta-analysis

BACKGROUND

Except conventional treatments, research on medical approach for radioiodine-refractory differentiated thyroid cancer (RR-DTC) was considered particularly challenging. Sorafenib, a novel biological agent, has been widely studied in the treatment of RR-DTC for years. We performed a systematic review and meta-analysis to explore the efficiency and safety of treating RR-DTC patients with sorafenib.

METHODS

An electronic search on PubMed/Medline and Embase was carried out to search associated articles. Fixed-effects or random-effects models were chose according to the heterogeneity.

RESULTS

A total of 15 eligible studies (636 patients) were included. As shown by the only randomised clinical trial-DECISION, sorafenib significantly improved progression-free survival (PFS) compared with placebo in patients with progressive RR-DTC. The pooled analysis indicated that there were 26% patients (95% CI: 0.19-0.34) achieved partial response (PR), and 44% patients (98% CI: 0.39-0.48) achieved stable disease (SD). The most frequent adverse effects (AEs) observed included hand-foot syndrome (HFS), diarrhoea, fatigue, alopecia, weight loss (WS) and rash, the incidence of all grades AEs for which were 71%, 60%, 59%, 55%, 51% and 50%, respectively. There were 68% patients (252/368), who had a dose reduction because of the drug toxicities and AEs.

CONCLUSIONS

Sorafenib could improve PFS in patients with progressive RR-DTC, comparing with placebo. Due to the resistance to conventional treatments, sorafenib is considered as a promising treatment for RR-DTC by most physicians specialised in this field. However, the use of sorafenib should be cautious due to a high incidence of AEs caused by the agent. More effective agents with less toxicities are warranted.

Estimating the Growth Rate of Lung Metastases in Differentiated Thyroid Carcinoma: Response Evaluation Criteria in Solid Tumors or Doubling Time?

Background: Estimating the growth rate of lung metastases for the treatment of patients with metastases of differentiated thyroid carcinoma (DTC) is important. This study aimed to evaluate survival outcomes according to different criteria for estimating the growth rate of lung metastases. Methods: Patients with macronodular (≥1 cm) lung metastases of DTC who underwent total thyroidectomy and high-dose radioactive iodine therapy between 1995 and 2013 were enrolled. The time to progressive disease (PD) by the Response Evaluation Criteria in Solid Tumors (RECIST), average tumor volume doubling time of the two dominant target lung lesions (midDT), and thyroglobulin doubling time (TgDT) were measured in each patient, and their association with disease-specific survival (DSS) was evaluated. Results: Forty-four patients with target lung metastatic nodules with an initial maximal diameter of 1.3 cm (median) were followed-up for a median of 6.8 years after the diagnosis of lung metastases. Based on RECIST, 12 patients (27.3%) showed fast tumor progression, with time to PD <1 year. When assessed by midDT, nine patients (20.5%) had midDT ≤1 year, showing rapid tumor progression. Seven of 33 patients (21.2%) who were negative for thyroglobulin antibody had midDT <1 year. Growth rates assessed by all three criteria were significantly associated with DSS. However, midDT had the highest predictive value for DSS, with a proportion of variation explained of 33.6%. Five-year DSS was 29.6% in patients with midDT ≤1 year, 50.0% in patients with time to PD <1 year, and 42.9% in patients with TgDT <1 year. Conclusions: Among the different criteria for estimating the growth rate of metastases in patients with lung metastases of DTC, midDT was the most powerful for predicting DSS, in comparison with RECIST and TgDT. Performing at least three serial chest computed tomography scans during the first year from the diagnosis of lung metastases can facilitate early detection of patients with rapid tumor progression and provide objective guidance for initiation of systemic therapy.

Efficacy and Limitations of Lenvatinib Therapy for Radioiodine-Refractory Differentiated Thyroid Cancer: Real-World Experiences

Background: The ultimate clinical goal of advanced cancer treatment is improvement of survival. Tyrosine kinase inhibitors (TKIs) were recently approved for radioiodine-refractory differentiated thyroid carcinoma (RR-DTC) that is resistant to conventional therapies since they have significant potential to improve survival in patients who previously had no more treatment strategies available. However, eligible patients are limited in clinical practice, making it difficult to accurately determine the efficacy of TKIs. Patients and Methods: We retrospectively analyzed the efficacy of lenvatinib at a single institution, enrolling 42 RR-DTC patients. Results: The best overall response was partial remission in 26 (62%) patients, stable disease in 10 (24%) patients, and progressive disease (PD) in 6 (14%) patients. The results indicated three-year overall survival (OS) and progression-free survival rates of 51.0% and 32.4%, respectively. Twenty-three (55%) patients had backgrounds that did not match the inclusion criteria of the Study of (E7080) Lenvatinib in Differentiated Cancer of the Thyroid (SELECT) trial. Furthermore, PD-experienced patients individually decided whether to continue lenvatinib, and 17 (41%) made the decision themselves; these patients had a three-year OS of 43.0% and postprogression survival (PPS) of 13.3 [95% confidence interval 6.1-not reached] months. Conclusions: Our real-world investigation revealed that patients have wide-ranging background characteristics, and the decision regarding continuation of therapy after PD is based on the patient's general condition. Our management protocol resulted in good PPS. Furthermore, our results indicated equivalent efficacy of lenvatinib as in the SELECT trial. In conclusion, lenvatinib proved effective for RR-DTC patients in a real-world setting.

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.

Innovative analysis of distant metastasis in differentiated thyroid cancer

Differentiated thyroid cancer (DTC) is the most common thyroid cancer with a relatively high survival rate. The association between certain risk factors of distant metastasis (DM) remains uncertain. In order to assess the prognosis of patients with DTC better, the present study aimed to investigate the synergistic effects between histologic subtype, tumor size, lymph node metastasis (LNM) status and extrathyroidal extension (ETE) on the incidence of DM in DTC. Data of 96,788 patients with DTC were obtained from the Surveillance, Epidemiology and End Results database. The association between clinicopathological factors and DM was evaluated by univariate and multivariate analyses. The synergistic effects of relevant factors were determined by measuring the relative excess risk due to interaction (RERI), attributable proportion due to interaction (AP) and synergy index (SI). The results demonstrated that tumor size, LNM status, histologic subtype and ETE were independent risk factors for DM [odds ratio (OR)=2.433; P<0.001; OR=3.998; P<0.001; OR=6.266; P<0.001; and OR=3.873; P<0.001, respectively]. In addition, a significant additive synergistic effect on DM was identified between ETE and histologic subtype, ETE and LNM status, as well as between ETE and tumor size (RERI=34.097; AP=0.706; SI=3.585; RERI=6.425; AP=0.410; SI=1.781; and RERI=76.973; AP=0.864; SI=7.930, respectively). Therefore, the results of this study revealed that ETE with follicular thyroid histology, N1 stage or large tumor size may have a synergistic effect on the risk of DM in patients with DTC. These results suggested that individualized treatment may benefit patients with DTC, and when ETE coexists with one of the identified risk factors, radical treatments may be required.

Prognostic role of the lymphocyte-to-monocyte ratio for clinical outcomes of patients with progressive radioiodine-refractory differentiated thyroid carcinoma treated by sorafenib

OBJECTIVES

The lymphocyte-to-monocyte ratio (LMR) reflects the status of tumour-infiltrating immune cells and host immunity. The LMR has been reported as a prognostic marker in various cancers. The present study evaluated the role of the LMR as a prognostic marker in patients with progressive radioiodine-refractory (RAIR) differentiated thyroid carcinoma (DTC).

DESIGN

Retrospective cohort study.

PATIENTS

Forty patients with progressive RAIR DTC who were treated by sorafenib with available baseline complete blood cell count data.

MEASUREMENTS

We assessed the response rate, progression-free survival (PFS) and overall survival (OS).

RESULTS

The patients were divided into low and high LMR groups based on their baseline LMRs (<4, n = 22, 55% and ≥4, n = 18, 45%, respectively). There were no significant differences in baseline characteristics between the groups. The OS curves differed significantly based on the LMR. The median OS of the low LMR group was 24.3 months and that of the high LMR group was not reached until the end of observation period (P = .015). The PFS curves and median PFS also differed significantly based on the LMR values (P = .019). In multivariate analysis, low LMR was an independent risk factor for all-cause mortality in patients with progressive RAIR DTC (hazard ratio, 2.64; 95% confidence interval: 1.04-6.72, P = .041).

CONCLUSION

A low LMR was associated with poor response rate, PFS and OS in patients with progressive RAIR DTC treated with sorafenib. Thus, LMR could be a simple prognostic biomarker in patients with progressive RAIR DTC.

Multikinase Inhibitor Treatment in Thyroid Cancer

Thyroid cancer is the most common endocrine malignancy. Most thyroid cancer types respond well to conventional treatment consisting of surgery and radioactive iodine (RAI) therapy. Unfortunately, some thyroid cancer types are resistant to surgical and RAI therapy. Multikinase inhibitors (MKIs) can be used in the treatment of advanced refractory thyroid cancers. The objective of this review is to give an update on MKI treatment (lenvatinib, sorafenib, sunitinib, cabozantinib, pazopanib, vandetanib) of thyroid cancer, regarding its efficacy and safety profile. We evaluated 212 articles through a PubMed search. A total of 20 articles met the inclusion and none the exclusion criteria. The studies showed promising progression-free survival rates compared to placebo treatment from earlier studies and similar or better results compared to the SELECT and DECISION trials. Adverse effects (AEs) are substantial in the treatment with MKIs. Almost all patients treated with these novel drugs experienced AEs. It is therefore crucial to focus on the management of AEs for a decent long-term outcome. The AEs are often more severe in patients with high efficacy of MKIs, which could indicate a correlation. Taken together, the novel therapeutic regimen with MKIs has shown favorable results in otherwise treatment-resistant thyroid cancer.

Improved survival after early detection of asymptomatic distant metastasis in patients with thyroid cancer

The incidence of thyroid cancer (TC) has been increasing in many countries and concerns about overdiagnosis are also widely shared. However, early detection may be helpful in some high-risk TC patients, such as those with initial distant metastasis. We conducted this study to evaluate the usefulness of early detection in TC patients with initial distant metastasis. We retrospectively reviewed the clinical data of 13,249 TC patients, and found 127 patients with initial distant metastasis. Enrolled patients were divided into two groups according to the diagnostic periods; before and after 2004, when the early detection of TC by ultrasonography began in earnest in Korea. Patients were also divided into two groups according to the presence of symptoms. Prior to 2004, 33 patients (1.7% of TC patients) were diagnosed with TC with initial distant metastasis and 16 (48.5%) of them died. After 2004, 94 patients (0.8% of TC patients) were diagnosed with TC with initial distant metastasis and 29 (30.9%) of them died. Prior to 2004, the disease-specific death rates were similar between the asymptomatic and symptomatic groups (46.2% vs. 50.0%, P = 0.566). Conversely, after 2004, the asymptomatic group showed a significantly lower disease-specific death rate as compared with that of the symptomatic groups (17.2% vs. 60.0%; P < 0.001). Early detection had a significant positive impact on survival outcomes only after 2004, especially in asymptomatic TC patients with initial distant metastasis.

Extended Real-World Observation of Patients Treated with Sorafenib for Radioactive Iodine-Refractory Differentiated Thyroid Carcinoma and Impact of Lenvatinib Salvage Treatment: A Korean Multicenter Study

Background: Treatment for patients with radioactive iodine (RAI)-refractory differentiated thyroid carcinoma (DTC) is challenging. Recently, two tyrosine kinase inhibitors (sorafenib and lenvatinib) have been approved and showed benefits for progression-free survival with tolerable adverse events. Methods: This is an extension study of a previous multicenter, retrospective cohort study of real-world experience in treating 98 patients with progressive RAI-refractory DTC with sorafenib. The primary endpoint was overall survival (OS). The efficacy of lenvatinib as salvage therapy after disease progression on first-line sorafenib was evaluated by comparing outcomes in 32 patients who were treated with lenvatinib with 41 patients who were not and therefore served as a no salvage treatment group. Results: The median OS of all 98 patients treated with sorafenib was 41.5 months, and the median progression-free survival was 13.5 months. Patients without disease-related symptoms before sorafenib treatment had better OS than those with symptoms (hazard ratio [HR] = 0.56 [95% confidence interval, CI 0.31-0.99], p = 0.048). Larger tumor size was associated with a minimally increased risk of death (HR = 1.02 [CI 1.00-1.03], p = 0.049). Best tumor response was not associated with OS (p = 0.490). Lenvatinib salvage treatment significantly improved OS in patients receiving it compared with those who did not (HR = 0.28 [CI 0.15-0.53], p < 0.001). The median OS from the time of disease progression after first-line sorafenib treatment was 4.9 months in no salvage treatment group, whereas it was not reached in the lenvatinib salvage group. Conclusions: The absence of disease-related symptoms and smaller tumor burden was associated with survival benefits of first-line sorafenib treatment in patients with progressive RAI-refractory DTC. Lenvatinib salvage therapy was effective in improving OS in patients with disease progression after first-line sorafenib.

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.

Tumor doubling time predicts response to sorafenib in radioactive iodine-refractory differentiated thyroid cancer

Sorafenib has emerged as an effective therapeutic option for radioactive iodine (RAI)-refractory, locally advanced or metastatic differentiated thyroid cancer (DTC). We investigated the efficacy and safety of sorafenib treatment in a real-world setting and unveil predictive markers of responsiveness to sorafenib. The treatment response, progression-free survival (PFS), overall survival, and adverse events (AEs) of sorafenib-treated RAI-refractory, locally advanced or metastatic DTC patients at three institutes were retrospectively reviewed, and their tumor doubling time was calculated by three investigators. Total eighty-five patients were treated with sorafenib, and seven patients discontinued sorafenib due to AEs before the first tumor assessment. The median PFS was 14.4 months, and the objective response rate was 10.3% in 78 patients who were able to evaluate the tumor response. Age, sex, histologic type, tumor location, RAI avidity, or the presence of FDG-PET uptake did not affect PFS. However, smaller tumor size (≤1.5 cm) of the target lesions in lung showed better PFS (hazard ratio [HR] 0.39, p = 0.01), and tumors with the shortest doubling time (≤6 months) had worse outcome (HR 2.70, p < 0.01). Because of AEs, dose reductions or drug interruptions were required in 64% of patients, and eventually, 23% of patients discontinued sorafenib permanently. The most common AE was hand-foot skin reaction (HFSR). Patients with severe HFSR showed better PFS, but there were no statistical significance (HR 0.65, p = 0.05). In conclusion, small tumor size and long doubling time of each target lesion can be a prognostic marker to predict the responsiveness to sorafenib in RAI-refractory DTC patients.