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

PURPOSE

To evaluate objective response rates (ORR), progression-free survival (PFS), and overall survival (OS) associated with tyrosine kinase inhibitors (TKIs) in patients with radioiodine refractory differentiated thyroid cancer (RR-DTC). Additionally, to compare: (i) ORR and PFS among patients treated with lenvatinib and sorafenib; (ii) ORR and PFS among patients receiving lenvatinib as first-line vs. second-line and; (iii) adverse effects (AEs) observed in patients treated with these medications.

METHODS

Retrospective analysis of RR-DTC adult patients treated with TKIs at the Division of Endocrinology, Hospital de Clinicas, University of Buenos Aires (March 2011-November 2023).

RESULTS

Among 43 patients included in the study, 32 received sorafenib (30 as first-line and 2 as second-line), while 29 received lenvatinib (12 as first-line and 17 as second-line). The median PFS and OS for the entire cohort were 32.7 and 39.0 months, respectively. Lenvatinib demonstrated a significantly higher ORR compared to sorafenib (37.9% vs. 9.4%, p = 0.008). However, both drugs exhibited similar median PFS (23.2 vs. 16.0 months, p = 0.419). No significant difference was observed in ORR and PFS between patients receiving first-line vs. second-line lenvatinib. Sorafenib-treated patients experienced higher rates of hand-foot skin syndrome (69% vs. 41%, p = 0.032) and alopecia (25% vs. 3%, p = 0.018), whereas lenvatinib-treated patients had higher rates of proteinuria (31% vs. 0%, p < 0.001) and grade 3 hypertension (31% vs. 9%, p = 0.034).

CONCLUSION

TKIs demonstrated efficacy and tolerability comparable to real-world data in RR-DTC. PFS was not statistically different between sorafenib and lenvatinib. Our study will help guide physicians in making informed decisions regarding treatment sequencing with TKIs in these patients.

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

BACKGROUND

Surgical resection is not always achievable in thyroid cancer patients. Neoadjuvant therapy is rarely used, but recent trends favor multikinase inhibitors or selective tyrosine kinase inhibitors. These aim to reduce tumor volume, enabling previously unfeasible surgeries.

PATIENTS AND METHODS

Consecutive patients with locally advanced malignant thyroid tumors who received systemic therapies with a neoadjuvant intention were included in this retrospective multicenter case series conducted in five Latin American referral centers. Primary outcomes were pre- versus post-neoadjuvant response evaluations using the Response Evaluation Criteria in Solid Tumors, feasibility of surgery and completeness of resection. Secundary outcomes were mortality and status at last visit.

RESULTS

Twenty-seven patients were included in this analysis. Patients with unresectable differentiated thyroid cancer (DTC) or poorly differentiated thyroid cancer (PDTC) received sorafenib (n=6) or lenvatinib (n=12), those with medullary thyroid cancer (MTC) were treated with vandetanib (n=5) or selpercatinib (n=1), and those with anaplastic thyroid cancer (ATC) harboring a BRAF V600E mutation (n=3) received dabrafenib and trametinib. The median patient age was 66 years (range 12-82), and 52% of the patients were female. In patients with PTC and PDTC, the median reduction in the diameter of the primary tumor was 25% (range 0-100%) after a median of 6 months of treatment. Surgical intervention was performed in ten (55%) of the patients. Among these, six patients (60%) achieved R0/R1 resection status. Six patients with MTC had a median reduction in tumor diameter of 24.5% (range 1-49) after a median treatment time of 9.5 months. Only one patient receiving selpercatinib, with a tumoral reduction of 25%, could undergo surgery, resulting in an R2 resection due to extensive mediastinal extension.Three patients with ATC showed a median tumor diameter reduction of 42% (range 6.7-50) after a median treatment time of 2 months. Two patients underwent surgical intervention and achieved R1 and R2 resection, respectively.

CONCLUSIONS

While neoadjuvant therapy achieved tumoral responses, surgical resection was feasible in 50% of DTC, 33% of ATC, and 16% of MTC patients, with R0/R1 resection in 26% of the cohort, underscoring the need for patient selection and further research in this area.

Optimizing Diagnostic Accuracy of Fine Needle Aspiration Biopsy Calcitonin Measurements in Detecting Medullary Thyroid Carcinoma

Background: The optimal cutoff value of calcitonin (Ctn) levels measured using an electrochemiluminescence immunoassay (ECLIA) obtained from the washout fluid of fine needle aspiration (FNA-Ctn) for the diagnosis of medullary thyroid carcinoma (MTC) is currently not established. We evaluated the diagnostic accuracy and clinical utility of FNA-Ctn for the diagnosis and location of MTC in patients with nodular or multinodular goiters. Methods: This was a case-control study nested on a prospective multicenter cohort of patients with nodular or multinodular goiter, normal or elevated serum Ctn, and thyroidectomy indications. Ctn and FNA-Ctn were measured using ECLIA methodology before surgery. From this nested cohort, MTC cases and controls (non-medullary pathology) were identified from the final pathological analysis. Cumulative incidence sampling of controls was randomly performed at a ratio of 1:2. Sensitivity, specificity, and area under the receiver operator curve (AUROC) were calculated for patients and the total number of thyroid nodules. Results: From 1272 patients included in the prospective cohort, 50 MTC cases and 105 controls were included. In this study, 286 thyroid nodules were evaluated (63 MTC and 223 non-MTCs). The median serum Ctn value was significantly higher in cases (525 pg/mL [interquartile range (IQR), 162.5-1.200]) than in controls (1.6 pg/mL [IQR, 0.5-5.6]; p < 0.001). The median FNA-Ctn value was significantly higher in MTC nodules (3.100 pg/mL [IQR, 450-45,200]) than in non-MTC nodules (0.5 pg/mL [IQR, 0.5-0.5]; p < 0.0001). In 11 MTC patients with multinodular goiter, the FNA-Ctn value was significantly higher in non-medullary nodules located in the same lobe where an MTC nodule was diagnosed (p = 0.0002). Overall, the FNA-Ctn AUROC was 0.99 [95% confidence interval, 0.98-1.0], and a threshold of ≥220 pg/mL showed 100% sensitivity and 98% specificity for MTC diagnosis. Conclusions: The use of FNA-Ctn measured by ECLIA showed adequate diagnostic accuracy for MTC diagnosis. Moreover, it may be clinically useful for localization in multinodular goiter when lobectomy is considered. Clinical Trial Registration: Clinicaltrials.gov NCT06067594.

Low-Density Lipoprotein Receptor Is a Key Driver of Aggressiveness in Thyroid Tumor Cells

We previously described the role of low-density lipoprotein (LDL) in aggressiveness in papillary thyroid cancer (PTC). Moreover, the MAPK signaling pathway in the presence of BRAF V600E mutation is associated with more aggressive PTC. Although the link between MAPK cascade and LDL receptor (LDLR) expression has been previously described, it is unknown whether LDL can potentiate the adverse effects of PTC through it. We aimed to investigate whether the presence of LDL might accelerate the oncogenic processes through MAPK pathway in presence or absence of BRAF V600E in two thyroid cell lines: TPC1 and BCPAP (wild-type and BRAF V600E, respectively). LDLR, PI3K-AKT and RAS/RAF/MAPK (MEK)/ERK were analyzed via Western blot; cell proliferation was measured via MTT assay, cell migration was studied through wound-healing assay and LDL uptake was analyzed by fluorometric and confocal analysis. TPC1 demonstrated a time-specific downregulation of the LDLR, while BCPAP resulted in a receptor deregulation after LDL exposition. LDL uptake was increased in BCPAP over-time, as well as cell proliferation (20% higher) in comparison to TPC1. Both cell lines differed in migration pattern with a wound closure of 83.5 ± 9.7% after LDL coculture in TPC1, while a loss in the adhesion capacity was detected in BCPAP. The siRNA knockdown of LDLR in LDL-treated BCPAP cells resulted in a p-ERK expression downregulation and cell proliferation modulation, demonstrating a link between LDLR and MAPK pathway. The modulation of BRAF-V600E using vemurafenib-impaired LDLR expression decreased cellular proliferation. Our results suggest that LDLR regulation is cell line-specific, regulating the RAS/RAF/MAPK (MEK)/ERK pathway in the LDL-signaling cascade and where BRAF V600E can play a critical role. In conclusion, targeting LDLR and this downstream signaling cascade, could be a new therapeutic strategy for PTC with more aggressive behavior, especially in those harboring BRAF V600E.

Is radioiodine ablation with 1.1 GBq (30 mCi) 131I necessary in low-risk thyroid cancer patients? Results from a long-term follow-up prospective study

BACKGROUND

In patients with low-risk differentiated thyroid cancer (DTC), remnant ablation with radioiodine (RA) after total thyroidectomy (TT) is controversial. No benefits have been demonstrated in terms of mortality or disease-free survival. Recent evidence found that RA did not improve mid-term outcomes.

PURPOSE

To evaluate initial response to treatment and long-term follow-up status in low-risk DTC patients after TT vs. TT + RA with ¹³¹I 1.11 GBq (30 mCi).

METHODS

Prospective multicenter non-randomized study; 174 low-risk DTC that underwent TT were recruited an divided in two groups according to RA (87 ablated and 87 non-ablated). Response to treatment was evaluated at 6-18 months after thyroidectomy and at the end of follow-up with measurements of thyroglobulin, and anti-thyroglobulin antibodies levels, and neck ultrasonography.

RESULTS

Baseline characteristics of both groups were similar. Ablated patients: median age 45.5 years, 84% females, 95.4% papillary thyroid carcinoma (PTC), mean tumor size 16 mm; non-ablated: median age 45 years, 88.5% females, 96.6% PTC, mean tumor size 14 mm. Response to initial treatment was similar between both groups, with < 2% of structural incomplete response. Final status was evaluated in 139 cases (median follow-up of 60 months). Among ablated patients, 82.8% had no evidence of disease (NED), 12% had an indeterminate response (IR) and 5% a biochemical incomplete response (BIR). Non-ablated patients had NED in 90%, IR in 8.7% and BIR in 1.2%. No statistical difference was found between groups (p = 0.29). No patient had evidence of structural disease at the end of follow-up.

CONCLUSIONS

Our findings support the recommendation against routine RA in low-risk DTC patients.

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

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

Non-invasive follicular neoplasm with papillary-like nuclear features: a challenging and infrequent entity in Argentina

PURPOSE

Non-invasive encapsulated follicular variant of papillary thyroid cancer was reclassified as non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). These neoplasms have an extremely low malignant potential. The aim of this study was (1) to assess the prevalence of NIFTP in patients with papillary thyroid carcinoma, (2) to evaluate their outcomes, and (3) to determine their molecular profile.

METHODS

Multicenter, descriptive, retrospective study. Patients with papillary thyroid cancer diagnosed from January 2006 to December 2016 from 11 referral centers were included. Diagnosis of NIFTP was based on criteria described by Nikiforov et al. in 2018. At least two pathologists agreed on the diagnosis. Two thousand six hundred and seventy-seven papillary thyroid cancer patients were included; 456 (17%) of them were follicular variant papillary thyroid cancer, and 30 (1.12%) fulfilled diagnostic criteria for NIFTP.

RESULTS

Each of the 30 included patients underwent a total thyroidectomy, and 50% were treated with radioiodine (median dose 100 mCi). After a median follow-up of 37 months, 84% of patients had an excellent response, 3% had an indeterminate response and data was missing in the remaining 13%. No metastatic lymph nodes, distant metastases or recurrences were found. RAS mutations were detected in 4 patients (13%).

CONCLUSION

The prevalence of NIFTP in our series is amongst the lowest reported. Excellent outcomes of patients underscore their low malignant potential. Molecular findings differ from other series, probably related to environmental or ethnic features of our population and the meticulous criteria for diagnosing NIFTP.

Prospective study on the clinical relevance of 18F-DOPA positron emission tomography/computed tomography in patients with medullary thyroid carcinoma

PURPOSE

¹⁸F-DOPA Positron Emission Tomography/Computed Tomography (¹⁸F-DOPA PET/CT) is a sensitive functional imaging method (65-75%) for detecting disease localization in medullary thyroid cancer (MTC). We aimed: (i) to assess the clinical usefulness of ¹⁸F-DOPA PET/CT in patients with MTC and elevated calcitonin (Ctn) and CEA levels and, (ii) to evaluate changes in disease management secondary to the findings encountered with this methodology.

METHODS

Thirty-six patients with MTC and Ctn levels ≥150 pg/ml were prospectively included. Neck ultrasound, chest contrast-enhanced CT, liver magnetic resonance imaging/abdominal three-phase contrast-enhanced CT and bone scintigraphy were carried out up to 6 months before the ¹⁸F DOPA PET/CT.

RESULTS

Seventy eight percent of patients were female and 27% had hereditary MTC. Median Ctn level was 1450 pg/ml [150-56620], median CEA level 413 ng/ml [2.9-7436]. Median Ctn DT was 37.5 months [5.7-240]; median CEA DT was 31.8 [4.9-180]. ¹⁸F-DOPA PET/CT was positive in 33 patients (91.6%); in 18 (56%) uptake was observed in lymph nodes in the neck or mediastinum, in seven cases (22%) distant metastases were diagnosed, and in eight additional patients (24%) both locoregional and distant sites of disease were found. Ctn and CEA levels were higher in patients with ≥3 foci of distant metastases. In 14 patients (38.8%), findings on ¹⁸F-DOPA PET/CT led to changes in management; surgery for locoregional lymph nodes was the most frequent procedure in 8 patients (22%).

CONCLUSION

¹⁸F-DOPA PET/CT was useful for the detection of recurrent disease in MTC, providing incremental value over conventional imaging procedures that led to modification in treatment strategies in nearly 40% of patients.

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.

Thyroid Inconveniences With Vaccination Against SARS-CoV-2: The Size of the Matter. A Systematic Review

After the beginning of COVID-19 vaccination campaigns, several reports of thyroid disease possibly related to the COVID-19 vaccination progressively appeared in the literature, raising the question of whether the thyroid disorder might be a SARS-CoV-2 vaccine complication. The aim of this study was to analyze the data about COVID-19 vaccination and thyroid disease, evaluate the size and quality of related literature, assess the type of these events, and investigate their timing of onset with respect the vaccination. Pubmed/MEDLINE and Cochrane were systematically reviewed until February 2022 to retrieve the largest number of original papers, case reports, and case series articles reporting thyroid disease after SARS-CoV-2 vaccination. Forty-six articles were included with a total of 99 patients aged from 26 to 73 years were described, of whom 74.75% female. Regarding the vaccination received, 49.49% of patients received Comirnaty (Pfizer/BioNTech), 14.14% CoronaVac (Sinovac), 12.12% Vaxzevria (Oxford/Astrazeneca), 11.11% Spikevax (Moderna), 3.03% Ad26.COV2.S (Janssen, Johnson & Johnson), one patient Covaxin (Bharat Biotech) and one patient Convidecia (Cansino). In 7 cases the thyroid disorder developed after the third dose with a combination of different vaccines. Regarding the type of thyroid disorder, 59 were subacute thyroiditis (SAT), 29 Graves' disease (GD), 2 co-occurrence of SAT and GD, 6 painless thyroiditis (PT), and single cases of thyroid eye disease and hypothyroidism associated with mixedema. The timeline between vaccination and thyroid disorder ranged between 0.5 to 60 days, with an average of 10.96 days. Considering the limited follow-up time, a complete remission was reported in most of SAT and PT cases while a persistence was observed in GD. In conclusion, both size and quality of published data about thyroid inconveniences after COVID-19 vaccination are limited; thyroid disorders may occur within 2 months after COVID-19 vaccination; among all thyroid diseases after COVID-19 vaccination, GD and SAT seem to be more frequent.

Impact of COVID-19 on the thyroid gland: an update

Coronavirus disease 2019 (COVID-19) is the pandemic of the new millennium. COVID-19 can cause both pulmonary and systemic inflammation, potentially determining multi-organ dysfunction. Data on the relationship between COVID-19 and thyroid have been emerging, and rapidly increasing since March 2020. The thyroid gland and the virus infection with its associated inflammatory-immune responses are known to be engaged in complex interplay. SARS-CoV-2 uses ACE2 combined with the transmembrane protease serine 2 (TMPRSS2) as the key molecular complex to infect the host cells. Interestingly, ACE2 and TMPRSS2 expression levels are high in the thyroid gland and more than in the lungs. Our literature search provided greater evidence that the thyroid gland and the entire hypothalamic-pituitary-thyroid (HPT) axis could be relevant targets of damage by SARS-CoV-2. Specifically, COVID-19-related thyroid disorders include thyrotoxicosis, hypothyroidism, as well as nonthyroidal illness syndrome. Moreover, we noticed that treatment plans for thyroid cancer are considerably changing in the direction of more teleconsultations and less diagnostic and therapeutical procedures. The current review includes findings that could be changed soon by new results on the topic, considering the rapidity of worldwide research on COVID-19.

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

Objective

The treatment of patients with differentiated thyroid cancer (DTC) was modified in the last decade towards a more individualized approach according to the risk of recurrence (RR). We compared the outcomes of patients with low and intermediate RR (LRR and IRR) who received or did not receive radioiodine remnant ablation (RRA) after assessing the dynamic risk.

Methods

We included 307 DTC patients with LRR and IRR submitted to total thyroidectomy. All patients were reclassified according to the dynamic risk stratification (low or high). Patients with high dynamic risk received RRA (141 patients).

Results

LRR patients who received RRA presented a frequency of structural incomplete response (SIR) of 5% at the end of the follow-up, compared to 2% in those who did not receive it (p=0.353). IRR patients treated with RRA had a frequency of SIR of 22%, compared to 5% in patients without RRA (p=0.008).

Conclusion

This study demonstrates the usefulness of dynamic risk assessment to decide RRA in a cohort with a long-term follow-up. The lower prevalence of SIR at the end of the follow-up in patients who did not receive RRA highlights the adequate selection of those who would not benefit from RRA, even with an intermediate risk of recurrence.

A Three-Domain Scoring System to Customize the Risk of Relapse of Differentiated Thyroid Carcinoma

PURPOSE

the validation of a new scoring model considering the principal risk factors of differentiated thyroid cancer (DTC) relapse.

METHODS

we evaluated all DTC patients treated with thyroidectomy and radioactive iodine (RAI) therapy. Three domains were considered: the demographic domain (age and gender), the surgical domain (histology and the American Thyroid Association risk categories), and the RAI-related domain (pre-RAI thyroglobulin and post-therapeutic ¹³¹I whole-body scan). The progression-free survival was assessed. The patients' sample was randomly split into a training and validation set. The three-domain score was calculated as the weighted sum of the levels of each significant factor, then scaled to an integer range (0-100) and, finally, stratified into terciles: mild risk 0-33, moderate risk 34-66, and severe risk 67-100.

RESULTS

907 DTC patients were included. The RAI-related domain was the most relevant factor in the score calculation. The tercile stratification identified significantly different survival curves: patients within the two upper terciles showed approximately 6 to 30 times more progressive risk than patients at mild risk.

CONCLUSION

we have validated a three-domain scoring system and the principal impact on this score is provided by the peri-RAI findings, whose prognostic role seems to be essential in risk identification.

Active surveillance in small cytological indeterminate thyroid nodules: a call to common sense?

PURPOSE

To describe the clinical characteristics and outcomes of patients with cytologically Bethesda IV category (B IV) thyroid nodules who opted for active surveillance.

MATERIALS AND METHODS

We prospectively evaluated 155 patients with a single thyroid nodule classified as B IV. Immediate molecular testing and/or thyroid surgery was offered, except when the patient (i) could not afford molecular testing/rejected the surgery, (ii) had a high surgical risk, (iii) had other disorders/comorbidities which needed to be addressed with higher priority, and (iv) had undetectable serum calcitonin levels, in whom active surveillance (AS) was performed.

RESULTS

From 155 patients, only two patients could afford molecular testing; 84% (n = 130) underwent immediate thyroid surgery: lobectomy was performed in only 8% (n = 10). AS was the initial management for 15% (n = 23) of the patients. The frequency of tumor enlargement was 14% (n = 3), after a median of 42 months (range, 7-72) of follow-up, without any evidence of lymph node or clinical distant metastases development. Deferred surgery was performed in 4 patients (17%) after a median of 24 months (range, 12-48) of AS. Follicular adenoma was diagnosed in three and a follicular variant of papillary thyroid carcinoma in one patient, all of them without evidence of disease after 12 months of follow-up.

CONCLUSIONS

Despite current guidelines does not support AS for indeterminate Bethesda IV nodules, our findings showed that most of these patients had excellent outcomes, in a setting where lobectomy was not the preference and the access to molecular testing was limited. Probably AS could be a valid alternative in these low-risk tumors in selected patients.

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

OBJECTIVE

The treatment of patients with differentiated thyroid cancer (DTC) was modified in the last decade towards a more individualized approach according to the risk of recurrence (RR). We compared the outcomes of patients with low and intermediate RR (LRR and IRR) who received or did not receive radioiodine remnant ablation (RRA) after assessing the dynamic risk.

METHODS

We included 307 DTC patients with LRR and IRR submitted to total thyroidectomy. All patients were reclassified according to the dynamic risk stratification (low or high). Patients with high dynamic risk received RRA (141 patients).

RESULTS

LRR patients who received RRA presented a frequency of structural incomplete response (SIR) of 5% at the end of the follow-up, compared to 2% in those who did not receive it (p=0.353). IRR patients treated with RRA had a frequency of SIR of 22%, compared to 5% in patients without RRA (p=0.008).

CONCLUSION

This study demonstrates the usefulness of dynamic risk assessment to decide RRA in a cohort with a long-term follow-up. The lower prevalence of SIR at the end of the follow-up in patients who did not receive RRA highlights the adequate selection of those who would not benefit from RRA, even with an intermediate risk of recurrence.

Complete response to larotrectinib treatment in a patient with papillary thyroid cancer harboring an ETV6-NTRK3 gene fusion

Larotrectinib, a highly selective TRK inhibitor, was administered to a patient with rapidly progressing radioactive iodine-refractory papillary NTRK3 fusion-positive thyroid cancer. The patient achieved a durable (sustained for 11 months) complete response after 2 months of treatment and complete intracranial responses in metastatic brain lesions after 7 months of treatment. Larotrectinib may provide a therapeutic route for patients with RAI-R-differentiated thyroid cancer who might otherwise have few treatment options.

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

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

[Response to lenvatinib in a pediatric patient with respiratory failure associated with papillary thyroid carcinoma]

Papillary thyroid cancer is the most common thyroid tumor in childhood. In advanced stages, it can present with respiratory failure. The treatment of choice is total thyroidectomy and radioactive iodine. In cases of unresectable tumors, therapy with multikinase inhibitors should be considered. A 10-year-old girl was referred for progressive respiratory failure. A diagnosis of papillary thyroid cancer with pulmonary metastases was made. Due to the presence of an unresectable tumor not subject to surgery, the compassionate use of lenvatinib was indicated, showing a rapid and favorable clinical response with resolution of respiratory failure on the ninth day. Early diagnosis of papillary thyroid cancer prevents severe respiratory morbidity caused by late diagnoses. The use of lenvatinib should be considered as a previous step towards first-line therapies (surgery and radioactive iodine) in cases with great local and distant involvement.

Acromegaly and thyroid cancer: analysis of evolution in a series of patients

Background

Acromegaly is associated with higher morbidity and mortality mainly due to cardiovascular disease. Data on the incidence and evolution of thyroid cancer in acromegaly are controversial. Our objective was to describe the characteristics of a group of acromegalic patients with differentiated thyroid carcinoma (DTC) and analyze their evolution.

Methods

This is a retrospective multicenter study of 24 acromegalic patients with DTC. The AJCC Staging System 8th Edition was used for TNM staging, and the initial risk of recurrence (RR), initial response and response at the end of follow-up (RFU) were defined according to the 2015 ATA Guidelines. As a control group, 92 patients with DTC without acromegaly were randomly included. Statistical analyses were done using SPSS Statistics 20.0.

Results

Median age of patients at diagnosis of acromegaly was 49.5 years (range 12–69). The median delay in diagnosis of acromegaly was 3 years (range 0.5–23). Mean baseline IGF-1 level was 2.9 ± 1.1 ULN. Median age at DTC diagnosis was 51.5 years (18–69).

At the moment of diagnosis of DTC, 58.3% of the patients had active acromegaly. Median time from DTC diagnosis to acromegaly control was 1.25 years (0.5–7). Mean DTC tumor diameter of the biggest lesion was 14.6 ± 9.2 mm, being multifocal in 37.5%. All tumors were papillary carcinomas, two cases being of an aggressive variety. Lymph node dissection was performed in 8 out of 24 patients and 62.5% had metastases. Only one patient had distant metastases. Radioiodine ablation was given to 87.5% of patients. Nineteen patients (79%) were stage I, four (17%) stage II and one (4%) stage IVb.

Initial RR was low in 87% (21/24), intermediate in 9% (2/24) and high in 4% (1/24) patient. RFU was: 83% (19/23) patients with no evidence of disease, 9% (2/23) with indeterminate response, 4% (1/23) with biochemical incomplete response and 4% (1/23) with structural incomplete response, at a median time of FU of 36.5 months.

When comparing RFU between acromegalics and controls no statistically significant differences were found.

Conclusions

Patients with acromegaly and DTC mostly had a low initial RR. When compared with the control group, we found that DTC patients with acromegaly did not have a worse evolution.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40842-020-00113-4.

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

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

Thyroid cancer in the Era of COVID-19

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

High rate incidence of post-surgical adverse events in patients with low-risk papillary thyroid cancer who did not accept active surveillance

PURPOSE

To describe the outcomes and the incidence of adverse events following active surveillance (AS) versus immediate surgery in patients with low-risk papillary thyroid carcinoma (PTC).

METHODS

We prospectively evaluated 286 patients who attended the Hospital de Clínicas, with a single thyroid nodule <1.5 cm classified as Bethesda category V or VI (PTC). Those patients with no aggressive features were considered as harboring a low-risk PTC and were offered AS or immediate surgery. For patients who opted for AS, surgery was recommended if tumor progression was observed. Post-operative adverse events were recorded for those patients treated with surgery (after AS or immediate surgery).

RESULTS

From 286 eligible patients, 164 harbored a low-risk PTC. Among these, 75% (n = 123) underwent immediate surgery and 25% (n = 41) opted for AS. Within the last group, increase in tumor size more than 3 mm was observed in 14.6 and 4.8% was diagnosed with lymph-node metastases after a median of 37.5 months (range, 12-65) of follow-up. One hundred and thirty five patients underwent surgery: in 123, it was immediate after diagnosis and in 12 after a median of 35 months (range, 12-65) of AS. Both groups had excellent oncological outcomes. The frequency of postoperative adverse events was 24.4%, which was permanent in 9.6% of cases. The immediate-surgery group presented higher incidence of permanent vocal cord paralysis (2.4 vs. 0%); permanent hypoparathyroidism (5.7 vs. 0%) and local complications (4 vs. 2.4%) compared with the AS group, all non-statistically significant.

CONCLUSIONS

The high incidence of postoperative complications observed in our media could be avoided if AS was performed as the initial approach in patients with low-risk PTCs. The frequency of tumor growth and LN metastases during AS was similar to other series.

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

PURPOSE

To describe the experience with radioiodine-resistant differentiated thyroid cancer (RR-DTC) patients treated with lenvatinib in two university hospitals from Argentina.

METHODS

Adult patients with a diagnosis of RR-DTC treated with lenvatinib from April 2017 to February 2020 were registered into a retrospective database. Primary objectives were assessment of progression-free survival (PFS) and tumor response evaluated according to RECIST v 1.1. Adverse events (AEs) were evaluated by using Common Terminology Criteria for Adverse Events v5.0.

RESULTS

Twenty-two patients were treated with lenvatinib, 13 of whom had previously received one or more multikinase inhibitors. Median duration of treatment was 7.1 months (2.2-24). Best overall response was complete response in one patient (4.5%), partial response in seven (31.8%), stable disease in seven (31.8%), and progressive disease in six (27.3%). Median PFS was 13.7 months (95% CI 3.2-24.2). All patients experienced at least one AE. Grade ≥3 AEs were observed in eight (36.4%) patients. Hypertension was the most frequent AE (63.6%) and the most common grade ≥3 AE (22.7%). Definitive withdrawal was necessary in two patients due to recurrent proteinuria (9%).

CONCLUSIONS

Tumor responses and PFS in our study were in line with other real-life clinical data and they seem to be inferior to the reported in the SELECT trial, probably related to the higher number of patients with prior MKI therapy, comorbidities, and poor performance status. Although virtually all patients experienced AEs, most of them were manageable and rarely a definitive withdrawal was necessary.

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

OBJECTIVES

To assess the value of ¹⁸F-FDG-PET/CT for detecting recurrent/persistent disease in patients with biochemical incomplete (BIR) or indeterminate response (IR) and to assess the impact of ¹⁸F-FDG-PET/CT on the therapeutic management of these patients.

METHODS

The study included patients with BIR, in whom ¹⁸F-FDG PET/CT was used within the diagnostic algorithm from our database. Patients with IR referred to our hospital with the ¹⁸F-FDG PET/CT already performed were also enrolled. All patients had neck ultrasonography with no structural changes. A change in therapeutic approach was defined as repeat surgery; administration of external beam radiotherapy; and/or the start of systemic therapy.

RESULTS

Sixty patients (85% women) aged 18-86 years were enrolled in this retrospective study. Of these, 75% had BIR and 25% IR. Increased FDG uptake suggesting locoregional lesions was seen in 40% of patients. Sensitivity, specificity, and diagnostic accuracy of ¹⁸F-FDG PET/CT to detect local disease were 95%, 87.5% and 90% respectively. The therapeutic approach was modified in 50% of patients with locoregional lesions.

CONCLUSIONS

Our study confirmed that ¹⁸F-FDG-PET/CT is a useful tool for detecting locoregional recurrence in thyroid cancer patients with BIR or IR with conflicting findings in standard diagnostic procedures. In 50% of patients with locoregional lesions, there was an immediate change in the treatment approach.

Dynamics of serum antithyroglobulin antibodies in patients with differentiated thyroid cancer

PURPOSE

Serum antithyroglobulin antibodies (sTgAb) affect the reliability of Tg measurement in patients with thyroid cancer. We compared the outcome of patients with detectable and undetectable sTgAb, stratified according to the initial risk of recurrence (RR); also the response to treatment in patients with detectable sTgAb treated with total thyroidectomy (TT) with and without radioiodine remnant ablation (RA) and the sTgAb trend in the long-term follow-up according to the initial response.

METHODS

We included 432 patients submitted to TT, with or without RA; 106 patients had detectable sTgAb levels. Median follow-up was 53 months.

RESULTS

There were no statistically significant differences considering presentation between negative or positive sTgAb subjects. The frequency of structural incomplete response (SIR) in low, intermediate, and high RR was similar. Undetectable sTgAb in patients was achieved in a median of 16 months in ablated patients compared with 11 months in those without RA (p = 0.0232). Patients without RA had a higher rate of undetectable sTgAb during the first 12 months. A SIR was observed in 3% of patients with declining sTgAb, in 19% of those with stable levels, and in 43% with increasing sTgAb (p = 0.004). The status of no evidence of disease was achieved more frequently in patients with initial sTgAb levels < 200 mUI/l, independently of the initial RR.

CONCLUSIONS

There was no impact of sTgAb on the initial clinical presentation and the response to therapy in low-risk patients treated with or without RA. sTgAb trend is more useful than an absolute value to predict a SIR.

[Thyroglossal duct remnants detected by ultrasonography after total thyroidectomy for thyroid carcinoma]

There are numerous reports of incidental findings of thyroglossal duct remnants (TGDR) after total thyroidectomy, but its implication on the outcome of patients with differentiated thyroid cancer (DTC) is unknown. The aim of this study was to determine the frequency of TGDR detected by ultrasonography after total thyroidectomy in patients with DTC and to evaluate the impact of this finding on the response to treatment. A total of 377 records of patients with DTC who received total thyroidectomy between January 1994 and January 2017 were reviewed. Patients with less than one year of follow-up after surgery were excluded. TGDR was diagnosed in 16 out of 377 (4.2%). Fifteen had a low risk of recurrence DTC and 13 of them were treated with radioactive iodine. All low risk patients had an excellent response to treatment. Only one with an intermediate risk of recurrence DTC had an initial structural incomplete response which changed to an indeterminate response after a modified central lymph node dissection. The median time of TGDR diagnosis after thyroidectomy was 5 years (1-16). Two patients underwent TGDR surgery due to the presence of a rapidly growing neck mass, 2.4 and 4 cm in size, detected 9 and 16 years after thyroidectomy, respectively. The prevalence of this condition seems to be rare. However, the appearance of a cystic mass during the follow-up of a patient with DTC cancer could be confused with metastatic disease. The diagnosis of TGDR seems not to have an impact on the response to treatment.

Active surveillance in papillary thyroid carcinoma: not easily accepted but possible in Latin America

OBJECTIVES

To determine the percentage of patients with papillary thyroid carcinoma (PTC) who accepted active surveillance as an alternative to surgery in our clinical practice and to describe the clinical characteristics and outcomes of patients with Bethesda category V and VI thyroid nodules who chose active surveillance.

SUBJECTS AND METHODS

We included 136 PTC patients from the Hospital de Clínicas, University of Buenos Aires without (i) US extrathyroidal extension, (ii) tumors adjacent to the recurrent laryngeal nerve or trachea, and/or (iii) US regional lymph-node metastasis or clinical distant metastasis. PTC progression was defined as the presence of i) a tumor larger than ≥ 3 mm, ii) novel appearance of lymph-node metastasis, and iii) serum thyroglobulin doubling time in less than one year. For patients with these features, surgery was recommended.

RESULTS

Only 34 (25%) of 136 patients eligible for active surveillance accepted this approach, and around 10% of those who accepted abandoned it due to anxiety. The frequency of patients with tumor enlargement was 17% after a median of 4.6 years of follow-up without any evidence of nodal or distant metastases. Ten patients who underwent surgical treatment after a median time of 4 years of active surveillance (AS) had no evidence of disease after a median of 3.8 years of follow-up after surgery.

CONCLUSION

Although not easily accepted in our cohort of patients, AS would be safe and easily applicable in experienced centers.

Unusual metastases from differentiated thyroid carcinoma: analysis of 36 cases

PURPOSE

Metastases of differentiated thyroid cancer (DTC) in sites different from lungs and bone are unusual (UM); their impact in management and prognosis remains unknown. Our aim was to evaluate the prevalence of UM, to describe their characteristics and to analyze their impact in disease outcome and mortality.

METHODS

We retrospectively reviewed the file records from 8 different centers. Those patients with DTC and UM were included. UM were diagnosed by: (i) biopsy/cytology and/or (ii) radioiodine (RAI) uptake associated to elevated thyroglobulin (Tg) levels and/or c) presence of one or more structural lesion/s with 18-FDG uptake in the PET/CT scan and elevated Tg levels.

RESULTS

Thirty-six (0.9%) out of a total of 3982 DTC patients were diagnosed with UM; 75% had papillary histology. The most frequent localization was central nervous system (CNS, 31%). UM were metachronous in 75%, symptomatic in 55.6% and fulfilled RAI-refractoriness criteria in 77.8% of cases. Metastatic lesions in lung/bone and/or locoregional disease were present in 34 cases (94.4%). Diagnosis of UM changed the therapeutic approach in 72.2% of patients. After a median follow up of 13 months, 21 (58.3%) patients died from DTC related causes. In 8 of them CNS progression was the immediate cause of death.

CONCLUSIONS

Prevalence of UM was low; they were frequently metachronic and RAI-refractory. Although UM were found in patients with widespread disease, their diagnosis usually led to changes in therapy. UM were associated with poor prognosis and high frequency of disease-specific mortality.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Rare complications of multikinase inhibitor treatment

OBJECTIVE

The advent of multikinase inhibitor (MKI) therapy has led to a radical change in the treatment of patients with advanced thyroid carcinoma. The aim of this manuscript is to communicate rare adverse events that occurred in less than 5% of patients in clinical trials in a subset of patients treated in our hospital.

SUBJECTS AND METHODS

Out of 760 patients with thyroid cancer followed up with in our Division of Endocrinology, 29 (3.8%) received treatment with MKIs. The median age at diagnosis of these patients was 53 years (range 20-70), and 75.9% of them were women. Sorafenib was prescribed as first-line treatment to 23 patients with differentiated thyroid cancer and as second-line treatment to one patient with advanced medullary thyroid cancer (MTC). Vandetanib was indicated as first-line treatment in 6 patients with MTC and lenvatinib as second-line treatment in two patients with progressive disease under sorafenib treatment.

RESULTS

During the follow-up of treatment (mean 13.7 ± 7 months, median 12 months, range 6-32), 5/29 (17.2%) patients presented rare adverse events. These rare adverse effects were: heart failure, thrombocytopenia, and squamous cell carcinoma during sorafenib therapy and squamous cell carcinoma and oophoritis with intestinal perforation during vandetanib treatment.

CONCLUSIONS

About 3 to 5 years after the approval of MKI therapy, we learned that MKIs usually lead to adverse effects in the majority of patients. Although most of them are manageable, we still need to be aware of potentially serious and rare or unreported adverse effects that can be life-threatening.

Impact of historic histopathologic sample review on the risk of recurrence in patients with differentiated thyroid cancer

OBJECTIVE

To compare the historic risk of recurrence (RR) and response to therapy to risk stratification estimated with historical pathology reports (HPRs) and contemporary re-review of the pathological slides in patients with differentiated thyroid cancer (DTC).

SUBJECTS AND METHODS

Out of 210 DTC patients with low and intermediate RR who underwent total thyroidectomy and remnant ablation in our hospital, 63 available historic pathologic samples (HPS) were reviewed. The RR and the response to therapy were evaluated considering historical histological features (histological type, tumor size, capsular invasion, number of lymph node metastases) and then, reassessed after observing additional histological features (vascular invasion, extrathyroidal extension, size of lymph node metastases, presence of extranodal extension, and/or status of the resection margins).

RESULTS

A change in the RR category was observed in 16 of 63 cases (25.4%). Out of 46 patients initially classified as low RR, 2 patients were reclassified as intermediate RR, 4 as high RR, and 1 as noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). Out of 17 patients initially classified as intermediate RR, 3 were reassigned to the low RR group, 5 as high RR, and 1 as NIFTP. The percentages of structural incomplete response at final follow-up changed from 2.2 to 0% (p = 1) in patients with low RR and from 6.3 to 20% (p = 0.53) in patients with intermediate RR.

CONCLUSION

A detailed report of specific features in the HPR of patients with DTC might give a more accurate RR classification and a better estimation of the response to treatment.

Outcomes of patients with bone metastases from differentiated thyroid cancer

Objective Bone metastases (BM) from differentiated thyroid cancer (DTC) are associated with poor survival rates. Due to the low frequency of this entity, we performed a multicentric retrospective study that aimed to evaluate the presentation, outcome and causes of death in this population. Subjects and methods We reviewed file records from 10 databases. BM were diagnosed by: i) biopsy and/or ii) radioiodine (RAI) bone uptake + elevated thyroglobulin (Tg) levels and/or c) bone uptake of 18-FDG in the PET-CT scan + elevated Tg levels. Results Fifty-two patients with DTC were included (44% male, mean age 54 years); 58% had papillary histology. BM were synchronous with DTC diagnosis in 46% of the participating cases. BM were symptomatic in 65% of the cases. Multiple BM were present in 65% of patients, while simultaneous metastatic disease in additional sites was found in 69%. Ninety-eight percent of patients received treatment for the BM, which included RAI therapy in 42 patients; 30 of them received cumulative RAI doses that were larger than 600 mCi 131I. The mean follow-up after a BM diagnosis was 34 months. The 2- and 5-year survival rates after diagnosis of the first BM were 64% and 38%, respectively. The status on the last evaluation was DTC-related death in 52% of the patients; 26% of them died from direct complications of BM or their treatments. Conclusion BM are usually radioiodine-refractory and are associated with a short overall survival, although most of the patients died of causes not directly related to the BM.

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

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

Should Age at Diagnosis Be Included as an Additional Variable in the Risk of Recurrence Classification System in Patients with Differentiated Thyroid Cancer

OBJECTIVE

To evaluate the influence of age at diagnosis on the frequency of structural incomplete response (SIR) according to the modified risk of recurrence (RR) staging system from the American Thyroid Association guidelines.

PATIENTS AND METHODS

We performed a retrospective analysis of 268 patients with differentiated thyroid cancer (DTC) followed up for at least 3 years after initial treatment (total thyroidectomy and remnant ablation). The median follow-up in the whole cohort was 74.3 months (range: 36.1-317.9) and the median age at diagnosis was 45.9 years (range: 18-87). The association between age at diagnosis and the initial and final response to treatment was assessed with analysis of variance (ANOVA). Patients were also divided into several groups considering age younger and older than 40, 50, and 60 years.

RESULTS

Age at diagnosis was not associated with either an initial or final statistically significant different SIR to treatment (p = 0.14 and p = 0.58, respectively). Additionally, we did not find any statistically significant differences when the percentages of SIR considering the classification of RR were compared between different groups of patients by using several age cutoffs.

CONCLUSIONS

When patients are correctly risk stratified, it seems that age at diagnosis is not involved in the frequency of having a SIR at the initial evaluation or at the final follow-up, so it should not be included as an additional variable to be considered in the RR classifications.

Radioactive iodine-refractory differentiated thyroid cancer: an uncommon but challenging situation

Radioiodine (RAI)-refractory thyroid cancer is an uncommon entity, occurring with an estimated incidence of 4-5 cases/year/million people. RAI refractoriness is more frequent in older patients, in those with large metastases, in poorly differentiated thyroid cancer, and in those tumors with high 18-fluordeoxyglucose uptake on PET/CT. These patients have a 10-year survival rate of less than 10%. In recent years, new therapeutic agents with molecular targets have become available, with multikinase inhibitors (MKIs) being the most investigated drugs. Two of these compounds, sorafenib and lenvatinib, have shown significant objective response rates and have significantly improved the progression-free survival in the two largest published prospective trials on MKI use. However, no overall survival benefit has been achieved yet. This is probably related to the crossover that occurs in most patients who progress on placebo treatment to the open treatment of these studies. In consequence, the challenge is to correctly identify which patients will benefit from these treatments. It is also crucial to understand the appropriate timing to initiate MKI treatment and when to stop it. The purpose of this article is to define RAI refractoriness, to summarize which therapies are available for this condition, and to review how to select patients who are suitable for them.

Selective use of sorafenib in the treatment of thyroid cancer

Sorafenib is a multiple kinase inhibitor (MKI) approved for the treatment of primary advanced renal cell carcinoma and advanced primary liver cancer. It was recently approved by several health agencies around the world as the first available MKI treatment for radioactive iodine-refractory advanced and progressive differentiated thyroid cancer. Sorafenib targets C-RAF, B-RAF, VEGF receptor-1, -2, -3, PDGF receptor-β, RET, c-kit, and Flt-3. As a multifunctional inhibitor, sorafenib has the potential of inhibiting tumor growth, progression, metastasis, and angiogenesis and downregulating mechanisms that protect tumors from apoptosis and has shown to increase the progression-free survival in several Phase II trials. This led to the Phase III trial (DECISION) which showed that there was an improvement in progression-free survival of 5 months for patients on sorafenib when compared to those on placebo. Adverse events with this drug are common but usually manageable. The development of resistance after 1 or 2 years is almost a rule in most patients who showed partial response or stabilization of the disease while on sorafenib, which makes it necessary to think of a plan for subsequent therapies. These may include the use of another MKI, such as lenvatinib, the second approved MKI for advanced differentiated thyroid cancer, or include patients in clinical trials or the off-label use of other MKIs. Given sorafenib's earlier approval, most centers now have access to its prescription. The goal of this review was to improve the care of these patients by describing key aspects that all prescribers will need to master in order to optimize outcomes.

Dynamic prediction of the risk of recurrence in patients over 60 years of age with differentiated thyroid carcinoma

OBJECTIVE

The reclassification of the risk according to the response to the initial treatment makes the treatment of differentiated thyroid cancer (DTC) vary in each individual. As the influence of age on this diagnostic strategy is unknown, we have decided to assess it in adults who are over 60 years of age.

SUBJECTS AND METHODS

Ninety patients with DTC above 60 years old were enrolled, with total thyroidectomy plus radioiodine ablation, negative anti-thyroglobulin antibodies, follow-up ≥ 2 years and with clinical and pathological information to classify the risk of recurrence according to ATA (American Thyroid Association) and reclassify based on the response to initial therapy according to MSKCC (Memorial Sloan Kettering Cancer Center). The structural persistence at the end of the follow-up was the gold standard of our analysis.

RESULTS

The structural persistence in ATA low, intermediate and high risk categories was 0, 38, and 100%, respectively. In the intermediate group, none of those with an excellent response to the initial treatment showed structural persistence, whereas 39% of those with an incomplete/indeterminate response showed structural persistence (p < 0.01).

CONCLUSIONS

The re-stratification according to the response to the initial treatment in patients over 60 years of age with an ATA intermediate risk of recurrence allowed for the distinction of disease-free patients at the end of the follow-up from those with structural persistence and a worse clinical progression.

Implementing the Modified 2009 American Thyroid Association Risk Stratification System in Thyroid Cancer Patients with Low and Intermediate Risk of Recurrence

OBJECTIVE

The primary purpose of this study was to validate the proposed modified 2009 American Thyroid Association Risk Stratification System (M-2009-RSS) in patients with thyroid cancer and to compare the findings with those of the 2009 ATA Risk of Recurrence (2009 ATA-RR) and the Ongoing Risk of recurrence system. The secondary purpose was to assess which risk stratification system had the best predictive value to foresee the probability of structural incomplete response or the no evidence of disease (NED) status at the end of follow-up.

SUBJECTS AND METHODS

This retrospective review included 149 patients with differentiated thyroid cancer who had low and intermediate 2009 ATA-RR and were treated at a single experienced center and followed-up for a median of 6 years (range 3-12 years). Each patient was risk stratified using both the 2009 ATA-RR and the M-2009-RSS. The primary endpoints were 1) the best response to initial therapy defined as either excellent response, biochemical or structural incomplete response, or indeterminate response; 2) clinical status at final follow-up defined as either NED, biochemical incomplete response, structural incomplete response, indeterminate response, or recurrence (biochemical or structural disease identified after a period of NED), and 3) ongoing RR defined as low or high risk according several outcomes after initial treatment.

RESULTS

Mean age of included patients was 45.3±13 years. Both the ATA 2009-RR and the M-2009-RSS provided clinically meaningful graded estimates with regard to the status of NED at the end of follow-up in low-risk patients (84% for 2009 ATA-RR and 74% for M-2009-RSS) or the likelihood of having persistent structural disease (0% for 2009 ATA RR and 3.6% for the M-2009-RSS). When patients were classified as low risk, the positive predictive value (PPV) and negative predictive value (NPV) to predict structural disease was 0% and 88.7% for the 2009 ATA-RR, 3.6% and 86.5% for the M-2009-RSS, and 1.6% and 68.2% for the ongoing RR (p=0.022 and 0.055 of chi-square test for PPV and NPV, respectively).

CONCLUSIONS

Despite expanding the definition of low risk to include small-volume lymph node metastases, minor extrathyroidal extension, and minimally invasive follicular thyroid cancer, the M-2009-RSS predicts clinical outcomes (structural incomplete response and NED at the end of follow-up) that are very similar to the previously validated 2009 ATA RR classification system.

Insulin resistance is another factor that increases the risk of recurrence in patients with thyroid cancer

The objective of this study was to evaluate the initial response to treatment and the long-term outcome of patients with papillary thyroid cancer (PTC), according to the modified 2014 risk of recurrence classification of the American Thyroid Association and the presence or absence of insulin resistance (IR). We retrospectively reviewed our database of 636 records and selected 171 patients in whom we had previously validated the ATA risk of recurrence (RR) classification. From these patients, 38 non-diabetic subjects were included for analysis according to the following criteria: age older than 18 years, classic papillary thyroid carcinoma, stable body mass index 5 years previous to PTC diagnosis and during the entire time of follow-up, low and intermediate RR, follow-up after initial treatment at least for 3 years, and absence of any drug treatment for the metabolic syndrome. The IR was evaluated through the homeostasis model assessment (HOMA) index. When equal or higher than 2.5, patients were considered as harboring IR. The initial response to treatment was classified as remission or persistent disease (biochemical and/or structural). The clinical status at final follow-up was defined as no evidence of disease, biochemical persistent disease, structural persistent disease, or recurrence (biochemical or structural disease identified after a period of no evidence of disease). RR was as follows: low: n=15, intermediate: n=23. The median follow-up of this patient cohort was 5.5 years (range 3-22 years). We found no statistically significant differences when the response to initial treatment was considered in low-risk patients with or without IR. However, remission was more frequently found in those patients without IR when the intermediate RR was considered (36 vs. 11%, p=0.01). When considering the status at final follow-up, we found more frequency of structural persistent disease in both, low and intermediate RR patients with IR (10 vs. 0%, p=0.02 and 45 vs.7%, p=0.01, respectively). In this series of patients with PTC, the state of IR was associated with increased frequency of structural persistent disease at final follow-up. The IR could have a deleterious effect on the outcome of patients with PTC.

Recombinant human thyroid-stimulating hormone-aided remnant ablation achieves a response to treatment comparable to that with thyroid hormone withdrawal in patients with clinically relevant lymph node metastases

It has already been shown that remnant ablation in patients with thyroid cancer and lymph node (LN) metastases has similar results when patients are prepared after recombinant human thyroid-stimulating hormone (rhTSH) therapy or thyroid hormone withdrawal (THW). Due to the current changes in the risk-of-recurrence classifications, we decided to evaluate the initial response to treatment and the outcome at medium-term follow-up in 40 consecutive patients with clinically relevant lymph nodes who received radioiodine remnant ablation after rhTSH therapy (n = 20) or THW (n = 20). Each patient received either 100 or 150 mCi 131-I for ablation based on TNM status, and the mean amounts of 131-I used in the 2 groups were not significantly different. An excellent response to treatment was observed in 45% of the patients prepared after rhTSH therapy compared to 20% of those prepared after THW (p = 0.08). Three patients (2 in the THW group and 1 in the rhTSH group) who had N1a in the initial surgery presented with structural persistence as an initial response to treatment. One patient in the THW group had a follow-up of the persistent disease with no surgical treatment, and 2 others received a lateral LN dissection. When the status at final follow-up was considered (median follow-up 3.3 years, range 3-4.2), 60% of the patients ablated after rhTSH therapy were considered with no evidence of disease, compared to 30% of those who underwent THW. The frequency of structural persistence (metastatic LN) was similar in the 2 groups (15 vs. 25%), and the distribution of the responses at final follow-up was not statistically significantly different (p = 0.12). We conclude that preparation after rhTSH therapy seems to be as effective as after THW for patients with clinically relevant LN metastases.

Biochemical persistence in thyroid cancer: is there anything to worry about?

To evaluate the outcome of differentiated thyroid cancer (DTC) patients with biochemical persistence of disease (BP) after initial treatment (total thyroidectomy with or without lymph node dissection (LND) and thyroid remnant ablation). BP was defined as suppressed thyroglobulin (Tg) levels <1 ng/ml and rhTSH-stimulated thyroglobulin (St-Tg) >1ng/ml, with no evidence of structural disease. Structural persistence/recurrence (SPR): clinically identifiable disease. We reviewed 278 records of DTC patients. Tg-Ab positive patients (n = 73) were excluded and 32 were included in the analysis (median age 45 years, range 18-77 years); risk of recurrence ATA was: low in 38 %, Intermediate in 47 %, and high in 15 % of patients. All subjects had Tg levels <1 ng/ml under thyroid hormone therapy. Patients were divided into three groups: Group 1: St-Tg 1-2 ng/ml, n = 6; Group 2: St-Tg 2-10 ng/ml, n = 17; Group 3: St-Tg > 10 ng/ml, n = 9. In 5/32 (16 %) patients, SPR was observed after a median follow-up of 6 years (range 2-23 years). In Group 1: all patients were considered with no evidence of disease after a median follow-up of 2 years (range 1-2.5 years). In Group 2: 13/17 (76.5 %) patients continued with only a BP after a median follow-up of 4 years (range 2-10 years) and 4/17 (23.5 %) patients with intermediate risk of recurrence had a structural persistence (lymph nodes metastasis) diagnosed between 1 and 3.5 years after initial assessment. Following LND, all of them remained with BP after a median of 2 years (range 1.5-5 years). In Group 3: 8/9 (89 %) patients had BP after a median follow-up of 7 years (range 2-23 years) and 1/9 (11 %) had a SPR diagnosed 28 months after initial assessment, LND was indicated but he continued with BP, 5 years after the second surgery. Most patients with DTC and BP present an indolent course of the disease. In these patients the diagnosis of the structural recurrence did not change the outcome because all of them continued with BP.