Efficacy and safety of peptide receptor radionuclide therapy in advanced radioiodine-refractory differentiated thyroid cancer and metastatic medullary thyroid cancer: a systematic review.

BACKGROUND: It has been shown that a subgroup of patients with differentiated thyroid cancer (DTC) and medullary thyroid carcinoma (MTC) would progress to advanced stages of thyroid cancer. Therefore, the present study was done to systematically review available evidence in order to investigate efficacy and safety of peptide receptor radionuclide therapy (PRRT) in the patients with advanced radioiodine refractory differentiated thyroid cancer (RR-DTC) and metastatic MTC. METHODS: For this purpose, relevant studies investigated safety and efficacy of PRRT in the patients with advanced RR-DTC and metastatic MTC were identified by searching Medline (Pubmed, Ovid, and Ebsco), Scopus, Embase, Web of Science, and Cochrane Library databases (from database inception to March 24, 2021). The review was performed according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement. Searching was done independently by two investigators. Two researchers independently extracted the data and any disagreement was adjudicated by consensus. Quality of the studies was assessed using the tool of case reports/series in systematic reviews. RESULTS: Among 2284 related papers, 41 papers met the inclusion criteria. A total of 157 patients with RR-DTC were treated with PPRT. Biochemical and objective responses (partial and complete) were observed in 25.3 and 10.5% of patients, respectively. Among 220 patients with metastatic MTC, biochemical and objective responses were observed in 37.2 and 10.6% of the patients, respectively. Forty-six deaths were reported in 95 patients with advanced RR-DTC. In addition, 63 deaths were observed in 144 patients with metastatic MTC. Major side effects were reported in 124 patients treated with 90Y -based agent. In the patients treated with 177Lu-DOTA-TATE and 111In-Octreotide, mild and transient hematologic or renal complications were reported. CONCLUSION: Findings of the study revealed that in the absence of the established treatment for the patients with RR-DTC and metastatic MTC, PRRT could be effective with few adverse events. TRIAL REGISTRATION: PROSPERO registration number: CRD42019125245 .

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.

A Phase II study of the safety and efficacy of lenvatinib in patients with advanced thyroid cancer.

AIM: To investigate the safety and efficacy of lenvatinib in advanced thyroid cancer. PATIENTS/METHODS: In this Phase II study, 51 Japanese patients with radioiodine-refractory differentiated thyroid cancer (RR-DTC), medullary thyroid cancer (MTC) or anaplastic thyroid cancer (ATC) received once-daily lenvatinib 24 mg. The primary end point was safety. RESULTS: All patients experienced ≥1 adverse event (AE); only one patient experienced an AE leading to discontinuation. The most common any-grade AEs were hypertension, decreased appetite, palmar-plantar erythrodysesthesia, fatigue and proteinuria. Response rates for RR-DTC: 68%; MTC: 22%; ATC: 24%. Median progression-free survival for RR-DTC: 25.8 months; MTC: 9.2 months; ATC: 7.4 months. CONCLUSION: Lenvatinib demonstrated a manageable safety profile, proven antitumor activity in RR-DTC and promising efficacy in MTC and ATC. CLINICAL TRIAL REGISTRATION: clinicaltrials.gov NCT01728623.

Selumetinib Activity in Thyroid Cancer Cells: Modulation of Sodium Iodide Symporter and Associated miRNAs.

BACKGROUND: The MEK (mitogen-activated protein kinase)⁻inhibitor selumetinib led to increased radioiodine uptake and retention in a subgroup of patients suffering from radioiodine refractory differentiated thyroid cancer (RR-DTC). We aimed to analyse the effect of selumetinib on the expression of sodium iodide symporter (NIS; SLC5A5) and associated miRNAs in thyroid cancer cells. METHODS: Cytotoxicity was assessed by viability assay in TPC1, BCPAP, C643 and 8505C thyroid cancer cell lines. NIS, hsa-let-7f-5p, hsa-miR-146b-5p, and hsa-miR-146b-3p expression was determined by quantitative RT-PCR. NIS protein was detected by Western blot. Radioiodine uptake was performed with a Gamma counter. RESULTS: Selumetinib caused a significant reduction of cell viability in all thyroid cancer cell lines. NIS transcript was restored by selumetinib in all cell lines. Its protein level was found up-regulated in TPC1 and BCPAP cells and down-regulated in C643 and 8505C cells after treatment with selumetinib. Treatment with selumetinib caused a down-regulation of hsa-let-7f-5p, hsa-miR-146b-5p and hsa-miR-146b-3p in TPC1 and BCPAP cells. In 8505C cells, a stable or down-regulated hsa-miR-146b-5p was detected after 1h and 48h of treatment. C643 cells showed stable or up-regulated hsa-let-7f-5p, hsa-miR-146b-5p and hsa-miR-146b-3p. Selumetinib treatment caused an increase of radioiodine uptake, which was significant in TPC1 cells. CONCLUSIONS: The study shows for the first time that selumetinib restores NIS by the inhibition of its related targeting miRNAs. Further studies are needed to clarify the exact mechanism activated by hsa-miR-146b-5p, hsa-miR-146b-3p and hsa-let7f-5p to stabilise NIS. Restoration of NIS could represent a milestone for the treatment of advanced RR-DTC.

Increased Progression-Free Survival with Cabozantinib Versus Placebo in Patients with Radioiodine-Refractory Differentiated Thyroid Cancer Irrespective of Prior Vascular Endothelial Growth Factor Receptor-Targeted Therapy and Tumor Histology: A Subgroup Analysis of the COSMIC-311 Study.

Background: Lenvatinib and sorafenib are standard of care first-line treatments for advanced, radioiodine-refractory (RAIR) differentiated thyroid cancer (DTC). However, most patients eventually become treatment-resistant and require additional therapies. The phase 3 COSMIC-311 study investigated cabozantinib in patients with RAIR DTC who progressed on lenvatinib, sorafenib, or both and showed that cabozantinib provided substantial clinical benefit. Presented in this study is an analysis of COSMIC-311 based on prior therapy and histology. Methods: Patients were randomized 2:1 (stratification: prior lenvatinib [yes/no]; age [≤65, >65 years]) to oral cabozantinib (60 mg tablet/day) or matched placebo. Eligible patients received 1-2 prior vascular endothelial growth factor receptor-targeting tyrosine kinase inhibitors for DTC (lenvatinib or sorafenib required), had a confirmed DTC diagnosis, and were refractory to or ineligible for radioiodine therapy. For this analysis, progression-free survival (PFS) and objective response rate (ORR) per Response Evaluation Criteria in Solid Tumors version 1.1 by a blinded independent radiology committee were evaluated by prior therapy (lenvatinib only, sorafenib only, both) and histology (papillary, follicular, oncocytic, poorly differentiated). Results: Two hundred fifty-eight patients were randomized (170 cabozantinib/88 placebo) who previously received sorafenib only (n = 96), lenvatinib only (n = 102), or both (n = 60). The median follow-up was 10.1 months. The median PFS (months) with cabozantinib/placebo was 16.6/3.2 (sorafenib only: hazard ratio [HR] 0.13 [95% confidence interval, CI, 0.06-0.26]), 5.8/1.9 (lenvatinib only: HR 0.28 [95% CI 0.16-0.48]), and 7.6/1.9 (both: HR 0.27 [95% CI 0.13-0.54]). The ORR with cabozantinib/placebo was 21%/0% (sorafenib only), 4%/0% (lenvatinib only), and 8%/0% (both). Disease histology consisted of 150 papillary and 113 follicular, including 43 oncocytic and 36 poorly differentiated. The median PFS (months) with cabozantinib/placebo was 9.2/1.9 (papillary: HR 0.27 [95% CI 0.17-0.43]), 11.2/2.5 (follicular: HR 0.18 [95% CI 0.10-0.31]), 11.2/2.5 (oncocytic: HR 0.06 [95% CI 0.02-0.21]), and 7.4/1.8 (poorly differentiated: HR 0.18 [95% CI 0.08-0.43]). The ORR with cabozantinib/placebo was 15%/0% (papillary), 8%/0% (follicular), 11%/0% (oncocytic), and 9%/0% (poorly differentiated). Safety outcomes evaluated were consistent with those previously observed for the overall population. Conclusions: Results indicate that cabozantinib benefits patients with RAIR DTC, regardless of prior lenvatinib or sorafenib treatments or histology. Clinical Trial Registration Number: NCT03690388.

Efficacy and safety of targeted therapy for radioiodine-refractory differentiated thyroid cancer: a meta-analysis.

PURPOSE: To evaluate the efficacy and safety of current targeted drug therapies for radioiodine-refractory differentiated thyroid cancer (RR-DTC). METHODS: This was a meta-analysis of relevant randomized controlled trials (RCTs) and single-arm studies searched across PubMed, Embase, Cochranes, and Web of Sciences up to September 12, 2023. Stata15.0 software was used to assess overall survival (OS), progression-free survival (PFS), disease control rate (DCR), objective response rate (ORR), and adverse effects (AEs). The Cochrane Bias Risk tool was used to assess literature quality and trial bias and RevMan 5.4 was used to generate a quality assessment map. RESULTS: A total of 8 RCTs and 17 single-arm studies with 3,270 patients on 7 drugs-vandetanib, sorafenib, lenvatinib, cabozantinib, apatinib, donafenib, and anlotinib-were included. Targeted therapy with these drugs effectively prolonged PFS and OS in patients with RR-DTC with overall HRs of 0.35 (95% CI 0.23-0.53, P < 0.00001) and 0.53 (95% CI 0.32-0.86, P < 0.00001), respectively. ORR and DCR were also prolonged, with overall RRs of 27.63 (95% CI 12.39-61.61, P<0.00001) and 1.66 (95% CI 1.48-1.86, P<0.00001), respectively. The subgroup analysis using Effect Size (ES) showed that apatinib had the best effect on ORR with an ES of 0.66 (95% CI 0.49-0.83, P<0.00001) and DCR with a ES of 0.95 (95% CI 0.91-1.00, P<0.00001). Common drug adverse effects included hypertension, diarrhea, proteinuria, and fatigue. CONCLUSION: The currently used targeted drug therapies for RR-DTC can significantly improve clinical outcomes and the new drug apatinib demonstrates promise for potentially superior performance.

Significance of Thyroglobulin Autoantibodies in Patients With Thyroid Cancer Treated With Lenvatinib.

Context: Serum thyroglobulin (Tg) is a highly sensitive and specific tumor marker, employed in post-operative management of patients with differentiated thyroid carcinomas. Tumor shrinkage of radioiodine-refractory thyroid cancer (RAIR-DTC) treated with multitarget kinase inhibitors as lenvatinib, expressed according to the Response Evaluation Criteria in Solid Tumors (RECIST), is also associated with a drastic reduction of Tg levels. However, interference caused by circulating thyroglobulin autoantibodies (TgAb) represents the main limitation in the clinical use of Tg. Objective: To evaluate if in RAIR-DTC TgAb could be considered a surrogate marker of Tg in monitoring response to treatment with lenvatinib. Design: We retrospectively evaluated patients who had started lenvatinib and correlated serum Tg and TgAb with the radiological response across visits. Setting: University of Pisa, Italy. Patients: We selected 9/97 RAIR-DTC patients with detectable TgAb. Intervention: None. Main Outcome Measures: None. Results: Tg values correlated neither with TgAb title nor with radiological response across visits. Greater decreases in TgAb titer correlated with favorable radiological response to lenvatinib after 1 month (Spearman's correlation = 0.74, P = .021) and 6 months (correlation = 0.61, P = .079). According to RECIST, patients with partial response showed a ∼10-fold greater decrease in TgAb compared to those with stable disease at 1 month (median TgAb decrease: -142 vs -14 IU/mL, P = .01) and those with progressive disease at 6 months (median TgAb decrease: -264 vs-24 IU/mL, P = .04). Conclusion: TgAb evaluation may represent a reliable surrogate marker for Tg trend in evaluating response of RAIR-DTC to treatment with lenvatinib. A multicentric study would be useful to confirm our results.

Health-related quality-of-life analyses from a multicenter, randomized, double-blind phase 2 study of patients with differentiated thyroid cancer treated with lenvatinib 18 or 24 mg/day.

BACKGROUND: In the phase 2 double-blind Study 211, a starting dose of lenvatinib 18 mg/day was compared with the approved starting dose of 24 mg/day in patients with radioiodine-refractory differentiated thyroid cancer (RR-DTC). Predefined criteria for noninferiority for efficacy in the 18 mg arm were not met; safety was similar in both arms. Impact of lenvatinib treatment on health-related quality-of-life (HRQoL) was a secondary endpoint of Study 211. METHODS: Patients with RR-DTC were randomly assigned to a blinded starting dose of lenvatinib 18 mg/day or 24 mg/day. HRQoL was assessed at baseline, every 8 weeks until Week 24, then every 16 weeks, and at the off-treatment visit, using the EQ-5D-3L and FACT-G instruments. Completion and compliance rates, mean change from baseline, and times to first and definitive deterioration were evaluated. RESULTS: Baseline EQ-5D and FACT-G scores, and overall changes from baseline, were comparable between patients in the lenvatinib 18 mg/day (n = 77) and 24 mg/day arms (n = 75). For the 18 mg versus 24 mg arms, least squares mean differences were -0.42 (95% CI -4.88, 4.03) for EQ-5D-VAS and 0.47 (95% CI -3.45, 4.39) for FACT-G total. Time to first deterioration did not significantly favor either arm; EQ-5D-VAS HR [18 mg/24 mg] 0.93 (95% CI 0.61-1.40), EQ-5D-HUI HR [18 mg/24 mg] 0.68 (95% CI 0.44-1.05), FACT-G total HR [18 mg/24 mg] 0.73 (95% CI 0.48-1.12). Time to definitive deterioration did not significantly favor either arm, though EQ-5D-VAS showed a trend in favor of the 24 mg arm (HR [18 mg/24 mg] 1.72; 95% CI 0.99-3.01); EQ-5D-HUI HR [18 mg/24 mg] was 0.96 (95% CI 0.57-1.63), FACT-G total HR [18 mg/24 mg] was 0.72 (95% CI 0.43-1.21). CONCLUSIONS: In Study 211, HRQoL for patients in the lenvatinib 18 mg/day arm was not statistically different from that of patients in the 24 mg/day arm. These data further support the use of the approved lenvatinib starting dose of 24 mg/day in patients with RR-DTC. GOV NUMBER: NCT02702388.

Theranostic Options for Radioiodine-Refractory Differentiated Thyroid Carcinoma: Recent Advances, Challenges, and Road Ahead.

Radioiodine-refractory differentiated thyroid cancer (RAIR-DTC), though uncommon, presents a considerable therapeutic challenge with poor long-term outcomes. Currently, tyrosine kinase inhibitors are the mainstay of treatment for advanced RAIR-DTC patients. However, these agents are associated with a multitude of adverse events with resultant deterioration in the quality-of-life of the patients. Targeted theranostic approaches with radiolabelled integrin binders and fibroblast activation protein- (FAP)-inhibitors seem to have a promising role in the management of such patients. This mini-review focuses on these novel theranostic strategies in RAIR-DTC, with emphasis on recent advances, existing challenges, and future directions.

Assessment of Treatment Response to Lenvatinib in Thyroid Cancer Monitored by F-18 FDG PET/CT Using PERCIST 1.0, Modified PERCIST and EORTC Criteria-Which One Is Most Suitable?

Background: We aimed to compare the established metabolic response criteria PERCIST and EORTC for their applicability and predictive value in terms of clinical response assessment early after the initiation of lenvatinib therapy in patients with metastatic radioiodine-refractory (RAI) thyroid cancer (TC). Methods: In 25 patients treated with lenvatinib, baseline and 4-month follow-up F-18 FDG PET/CT images were analyzed using PERCIST 1.0, modified PERCIST (using SUVpeak or SUVmax) and EORTC criteria. Two groups were defined: disease control (DC) and progressive disease (PD), which were correlated with PFS and OS. Results: PERCIST, mPERCIST, PERCISTmax and EORTC could be applied in 80%, 80%, 88% and 100% of the patients based on the requirements of lesion assessment criteria, respectively. With PERCIST, mPERCIST, PERCISTmax and EORTC, the patients classified as DC and PD ranged from 65 to 68% and from 32 to 35%, respectively. Patients with DC exhibited a longer median PFS than patients with PD for EORTC (p < 0.014) and for PERCIST and mPERCIST (p = 0.037), respectively. Conclusion: EORTC and the different PERCIST criteria performed equally regarding the identification of patients with PD requiring treatment changes. However, the applicability of PERCIST 1.0 using SULpeak seems restricted due to the significant proportion of small tumor lesions.

Efficacy and safety of multi-kinase inhibitors in patients with radioiodine-refractory differentiated thyroid cancer: a systematic review and meta-analysis of clinical trials.

OBJECTIVES: Radioiodine-refractory differentiated thyroid cancer (RAI-rDTC) has frequently been associated with poor prognosis. We conducted a meta-analysis of published randomized controlled trials to evaluate multi-kinase inhibitors' efficacy and safety profile treatment. METHODS: A comprehensive search was conducted using PubMed, Embase, Cochrane, and Medline databases. The quality of literature and trial risk of bias was assessed using the Cochrane risk of bias tool, while the results of progression-free survival (PFS), overall survival (OS), and adverse events (AEs) were evaluated using RevMan5.3 software. RESULTS: Treatment with MKIs significantly improved PFS and OS, but AEs were significantly higher than those in the control group (P < 0.01). The studies demonstrated the median PFS (HR 0.30, 95% CI: 0.18-0.50, P < 0.00001) and OS (HR 0.70, 95% CI: 0.57-0.88, P = 0.002) in RAI-rDTC patients treated with MKIs, and the median PFS of papillary thyroid carcinoma (HR0.28, 95% CI: 0.22-0.37, P < 0.00001) along with follicular thyroid carcinoma (HR0.14, 95%CI 0.09-0.24, P < 0.00001) were extended. CONCLUSION: MKIs significantly prolonged PFS and OS in patients with RAI-rDTC (P < 0.01). Our recommendation is to use MKIs carefully in patients after evaluating their health status to maximize treatment benefits and minimize adverse effects.

Novel Fibroblast Activation Protein Inhibitor-Based Targeted Theranostics for Radioiodine-Refractory Differentiated Thyroid Cancer Patients: A Pilot Study.

Background: This exploratory study was meant to assess clinical and safety data with a novel fibroblast activation protein inhibitor-based targeted theranostics as a salvage treatment option in radioiodine-refractory differentiated thyroid cancer (RR-DTC) patients who had progressed on tyrosine kinase inhibitors. Methods: Patients with metastatic RR-DTC who progressed on sorafenib/lenvatinib were prospectively recruited. If [68Ga]Ga-DOTA.SA.FAPi positron emission tomography/computed tomography scan demonstrated moderate-to-excellent uptake in metastases, and patients had given informed consent, they received intravenous [177Lu]Lu-DOTAGA.(SA.FAPi)2 as therapy at eight-weekly intervals. The primary endpoints were thyroglobulin (Tg) response and functional imaging response. The secondary endpoints were visual analog score (VAS) and Eastern Cooperative Oncology Group (ECOG) performance status. The grading of toxicities was performed by using Common Terminology Criteria for Adverse Events (CTCAEV5.0). The sequential images were acquired by a dual-headed gamma camera, and dosimetric calculations were performed by using OLINDA/EXM V2.1. Results: Fifteen patients were recruited [age: 55 ± 9 years (range: 39-67)]. [177Lu]Lu-DOTAGA.(SA.FAPi)2 had median whole-body Teff of 88.06 hours (interquartile range [IQR]: 86.6-99). The colon was identified as a critical organ. The whole-body effective dose was 1.62E-01 ± 1.53E-02 mSv/MBq. A total of 45 cycles were administered, and the median cumulative administered activity was 8.2 ± 2.7 GBq (range 5.5-14 GBq). The median absorbed doses to the tumor lesions were 1.08E+01 (IQR: 4.16E+00 to 8.97E+01) mSv/MBq per cycle. The Serum Tg level significantly decreased after treatment [(median Tg: baseline-10,549 ng/mL (IQR: 3066.5-39,450) versus at the time of assessment: 5649 ng/mL (IQR: 939.5-17,099), p = 0.0005)]. Molecular response assessment revealed no complete response; however, partial response was documented in four, and stable disease in three patients. The VASmax scores [pre-therapy: 9 (IQR: 8-10) versus follow-up: 6 (3-6) (p-0.0001)], and ECOG [3, (IQR: 2-3 vs. 2, (IQR: 2-3) (p-0.0078)] performance scores significantly improved after treatment. None of the patients experienced grade III/IV hematological, renal, or hepatotoxicity. Conclusion: These preliminary data suggest that the novel molecule [177Lu]Lu-DOTAGA.(SA.FAPi)2 is safe, seems effective, and, most importantly, opens up a new avenue for the treatment of aggressive RR-DTC patients who have exhausted all standard line of treatments.

Initial clinical and treatment patterns of advanced differentiated thyroid cancer: ERUDIT study.

Background: Up to 30% of differentiated thyroid cancer (DTC) will develop advanced-stage disease (aDTC) with reduced overall survival (OS). Objective: The aim of this study is to characterize initial diagnosis of aDTC, its therapeutic management, and prognosis in Spain and Portugal. Methods: A multicentre, longitudinal, retrospective study of adult patients diagnosed with aDTC in the Iberian Peninsula was conducted between January 2007 and December 2012. Analyses of baseline characteristics and results of initial treatments, relapse- or progression-free survival ((RP)FS) from first DTC diagnosis, OS, and prognostic factors impacting the evolution of advanced disease were evaluated. Results: Two hundred and thirteen patients (median age: 63 years; 57% female) were eligible from 23 hospitals. Advanced disease presented at first diagnosis (de novo aDTC) included 54% of patients, while 46% had relapsed from early disease (recurrent/progressive eDTC). At initial stage, most patients received surgery (98%) and/or radioiodine (RAI) (89%), with no differences seen between median OS (95% CI) (10.4 (7.3-15.3) years) and median disease-specific-survival (95% CI) (11.1 (8.7-16.2) years; log-rank test P = 0.4737). Age at diagnosis being <55 years was associated with a lower risk of death (Wald chi-square (Wc-s) P < 0.0001), while a poor response to RAI to a higher risk of death ((Wc-s) P < 0.05). In the eDTC cohort, median (RP)FS (95% CI) was of 1.7 (1.0-2.0) years after RAI, with R0/R1 surgeries being the only common significant favourable factor for longer (RP)FS and time to aDTC ((Wc-s) P < 0.05). Conclusion: Identification of early treatment-dependent prognostic factors for an unfavourable course of advanced disease is possible. An intensified therapeutic attitude may reverse this trend and should be considered in poor-performing patients. Prospective studies are required to confirm these findings.

Scoring system and a simple nomogram for predicting radioiodine refractory differentiated thyroid cancer: a retrospective study.

BACKGROUND: Differentiated thyroid carcinoma (DTC) originates from abnormal follicular cells and accounts for approximately 90-95% of thyroid malignancies. The diagnosis of radioiodine refractory DTC (RR-DTC) is based on clinical evolution and iodine uptake characteristics rather than pathological characteristics. Thus, it takes a long time to become apparent, and the definition of RR-DTC covers multiple aspects. We aimed to analyze the clinical and molecular imaging characteristics of patients with RR-DTC and identify independent predictors to develop an RR-DTC scoring system and a simple nomogram for predicting the probability of RR-DTC. We reviewed the data of 404 patients with metastatic DTC who underwent both post-RAI WB therapy scintigraphy and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography. Data on the clinical features and molecular characteristics of RR-DTC and non-RR-DTC cases were obtained from medical records. We screened for predictors using univariate analyses, obtained independent predictors through multivariate analyses, and then established a scoring system and a simple nomogram for predicting RR-DTC according to the corresponding odds ratio (OR) values. RESULTS: Diagnosis at age ≥ 48 years (OR, 1.037; 95% confidence interval [CI], 1.007-1.069), recurrence between the operation and iodine-131 treatment (OR, 7.362; 95% CI 2.388-22.698), uptake of 18F-FDG (OR, 39.534; 95% CI 18.590-84.076), and the metastasis site (OR, 4.365; 95% CI 1.593-11.965) were highly independently associated with RR-DTC. We established a scoring system for predicting RR-DTC, showing that the area under the receiver operating characteristic curve (AUC) with a cutoff value of 10 points (AUC = 0.898) had a higher discernibility than any other single independent predictor. The risk factors of RR-DTC in nomogram modeling include diagnosis at age ≥ 48 years, recurrence between the operation and iodine-131 treatment, uptake of 18F-FDG, and the site of metastasis. The concordance index (c-Index) of the nomogram was 0.9. CONCLUSIONS: We demonstrated that a predictive model based on four factors has a good ability to predict RR-DTC. An index score ≥ 10 points was found to be the optimal index point for predicting RR-DTC. Moreover, this nomogram model has good predictive ability and stability. This model may help establish an active surveillance or appropriate treatment strategy for RR-DTC cases.

Lenvatinib: an investigational agent for the treatment of differentiated thyroid cancer.

INTRODUCTION: Differentiated thyroid cancer (DTC; >90% of all TCs) derives from follicular cells. Surgery is the main therapeutic strategy, and radioiodine (RAI) is administered after thyroidectomy. When DTC progresses, it does not respond to RAI and thyroid-stimulating hormone (TSH)-suppressive thyroid hormone treatment, and other therapies (i.e. surgery, external beam radiation therapy and chemotherapy) do not lead to a better survival. Thanks to the understanding of the molecular pathways involved in TC progression, important advances have been done. Lenvatinib is a multitargeted tyrosine kinase inhibitor of VEGFR1-3, FGFR1-4, PDGFRα, RET, and KIT signaling networks implicated in tumor angiogenesis, approved in locally recurrent or metastatic, progressive, RAI-refractory DTC. Unmet needs regarding the patient clinical therapy responsiveness in aggressive RAI-refractory DTC still remain. AREAS COVERED: We provide an overview from the literature of in vitro, in vivo and real-life studies regarding lenvatinib as an investigational agent for the treatment of aggressive TC. EXPERT OPINION: According to the SELECT trial, the treatment should be initiated with a dosage of 24 mg/day, subsequently decreasing it in relation to the side effects. The decision making process in patients with aggressive RAI-refractory DTC should be personalized and the potential toxicity should be properly managed.

Impact of lung metastases on overall survival in the phase 3 SELECT study of lenvatinib in patients with radioiodine-refractory differentiated thyroid cancer.

BACKGROUND: Lung metastases may worsen overall survival (OS) in patients with radioiodine-refractory differentiated thyroid cancer (RR-DTC). We investigated (post hoc) the impact of lung metastases on survival in SELECT (a phase 3 study). PATIENTS AND METHODS: 392 patients with RR-DTC were randomised 2:1 to lenvatinib 24 mg daily (n = 261) or placebo (n = 131). Placebo-treated patients could crossover to open-label lenvatinib following progression. Patients were grouped by size of baseline lung metastases. Safety/efficacy outcomes, collated by these lung-metastases subgroups, were generated. RESULTS: Lenvatinib-treated population distributions per baseline lung metastases subgroup were any lung metastases (target/nontarget lesions; n = 226), and by maximum size of target lung lesions ≥1.0 cm (n = 199), ≥1.5 cm (n = 150), ≥2.0 cm (n = 94) and <2.0 cm (n = 105). In patients with any lung metastases, no statistically significant difference in OS was observed between treatment arms (HR: 0.76; 95% CI: 0.57-1.01; P = 0.0549). Median OS for lung metastases of ≥1.0 cm was 44.7 months (lenvatinib) versus 33.1 months (placebo) (HR: 0.63; 95% CI: 0.47-0.85; P = 0.0025). OS was significantly prolonged with lenvatinib versus placebo among patients with lung metastases of ≥1.0 cm, ≥1.5 cm, ≥2.0 cm and <2.0 cm; median OS was shorter in the ≥2.0 cm subgroup (lenvatinib: 34.7 months) versus other subgroups (lenvatinib: 44.1-49.2 months). Multivariate analysis demonstrated lenvatinib significantly prolonged OS in patients with lung metastases of ≥1.0 cm after adjustment for baseline characteristics. CONCLUSIONS: Lenvatinib treatment resulted in longer OS in patients with lung metastases of ≥1.0 cm versus placebo (even with the 89% crossover rate). Early initiation of lenvatinib may improve outcomes in patients with RR-DTC and lung metastases of ≥1.0 cm. SOURCE STUDY REGISTRATION: ClinicalTrials.Gov Identifier: NCT01321554.

[18F]-FDG-PET/CT Correlates With the Response of Radiorefractory Thyroid Cancer to Lenvatinib and Patient Survival.

CONTEXT: 18F-fluoro-2-deoxy-D-glucose positron emission tomography-computed tomography ([18F]-FDG-PET/CT)-positive metastatic lesions in radioiodine-refractory differentiated thyroid cancer (RAI-R DTC) have a poor prognosis and lenvatinib represents the best therapy. OBJECTIVE: We investigated the role of [18F]-FDG-PET/CT in the evaluation of metabolic response and prediction of the outcome of RAI-R DTC patients treated with lenvatinib. METHODS: Patients (n = 33) with progressive metastatic RAI-R DTC who were treated with lenvatinib were investigated at baseline and during follow-up with biochemical (thyroglobulin and thyroglobulin antibodies), morphological (whole-body CT scan) and metabolic ([18F]-FDG-PET/CT) evaluation. RESULTS: Nineteen (57.6%) patients showed the greatest metabolic response at the first [18F]-FDG-PET/CT scan, performed after 4 weeks of lenvatinib, while 5/33 (15.1%) patients had this response later. Moreover, 66.7% of patients had both a metabolic response at the first [18F]-FDG-PET/CT scan and a morphological response at the first CT scan. We observed a correlation between the metabolic response at [18F]-FDG-PET/CT scan performed after 4 weeks of treatment and the biochemical response at the same time in 60.6% of patients. The median overall survival (OS) was significantly longer in patients with either a metabolic response at last [18F]-FDG-PET/CT (40.00 vs 8.98 months) or a morphological response at last CT scan (37.22 vs 9.53 months) than in those without response. Moreover, the OS was longer in patients with a metabolic response at [18F]-FDG-PET/CT performed after 4 weeks of treatment (36.53 vs 11.28 months). CONCLUSIONS: Our data show that [18F]-FDG-PET/CT can early predict the response to lenvatinib and correlates with the OS of RAI-R DTC patients treated with this drug.

Exploratory Analysis to Predict Optimal Tumor Burden for Starting Lenvatinib in Patients With Radioiodine-Refractory Differentiated Thyroid Cancer.

BACKGROUND: We previously reported that a high tumor burden is a prognostic factor based on an analysis of 26 patients with radioactive iodine-refractory differentiated thyroid cancer (RR-DTC) who were treated with lenvatinib. However, the optimal tumor burden for starting lenvatinib still remains to be defined. The aim of this retrospective study was to further explore in the same patient cohort the optimal timing for the start of lenvatinib by focusing on the pre- and post-treatment tumor burden. METHODS: The 26 patients were treated with lenvatinib from 2012 to 2017. We explored the optimal timing for the start of lenvatinib by comparing the characteristics of long-term responders who were defined as patients with progression-free survival ≥ 30 months and non-long-term responders. RESULTS: Long-term responders had a smaller post-treatment tumor burden at maximum shrinkage than non-long-term responders. Further, post-treatment tumor burden had a strong linear correlation with baseline tumor burden. We created an estimation formula for baseline tumor burden related to prognosis, using these regression lines. Patients with a sum of diameters of target lesions < 60 mm or maximum tumor diameter < 34 mm at baseline were estimated to have significantly better survival outcomes. CONCLUSIONS: We found a strong linear correlation between pre- and post-treatment tumor burden. Our results suggested a cut-off value for baseline tumor burden for long-term prognosis among patients treated with lenvatinib.

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.

177Lu-DOTATATE and 177Lu-prostate-specific membrane antigen therapy in a patient with advanced metastatic radioiodine-refractory differentiated thyroid cancer after failure of tyrosine kinase inhibitors treatment.

Patients with radioiodine-refractory differentiated thyroid cancer (RrDTC) have only a limited or no benefit from radioiodine therapy. For these patients, tyrosine kinase inhibitors have demonstrated encouraging results in advanced RrDTC. Nevertheless, these therapies are related with substantial side effects and a high cost. Somatostatin receptor-based therapies have shown promising findings in advanced RrDTC. Recently, prostate-specific membrane antigen (PSMA) expression was seen in advanced RrDTC in imaging studies. This study presents a case of RrDTC who was treated with 177Lu-DOTATATE and 177Lu-PSMA, presumably as a first report in this regard.