External beam radiotherapy with or without concurrent chemotherapy in advanced or recurrent non-anaplastic non-medullary thyroid cancer

Oncocytic carcinoma of the thyroid: Conclusions from a 20-year patient cohort

BACKGROUND

Oncocytic carcinoma (OCA) was recently reclassified as a distinct differentiated thyroid carcinoma (DTC). Given its rarity, OCA studies are limited. This study describes the characteristics of OCA in a 20-year cohort.

METHODS

Retrospective analysis of patients with OCA at a single tertiary care hospital from 2000 to 2021.

RESULTS

Fifty-one OCA patients (22M:29F) were identified. The mean age at diagnosis was 60.3 years; 90% presented as palpable mass; 24% had a family history of thyroid cancer. None had vocal fold paresis. On ultrasound, most tumors were solid and hypoechoic. FNA (n = 14) showed Bethesda-4 lesions in 93%. All were treated surgically. Histologically, 63% demonstrated angioinvasion, 35% had lymphovascular invasion, and 15% had extrathyroidal extension. Radioactive iodine was used as adjunct therapy in 77%.

CONCLUSION

OCA has distinct features that distinguish it from other DTCs, and additional focused studies will help clarify the aggressive nature, treatment options, and prognosis of the disease.

Long-term clinical outcomes and prognostic factors for patients with papillary thyroid carcinoma with other organ invasions after adjuvant radioactive iodine

PURPOSE

Papillary thyroid carcinoma (PTC) with other organ invasions is directly related to patient prognosis and quality of life; however, studies on the clinical outcomes of adjuvant radioactive iodine (RAI) for PTC with other organ invasions are limited. This study aimed to clarify the clinical outcomes and prognostic factors for patients with PTC with other organ invasions after adjuvant RAI.

METHODS

Patients with PTC with other organ invasions without distant metastases who underwent surgery and adjuvant RAI were retrospectively reviewed. We evaluated the initial responses based on the American Thyroid Association guidelines and survival rates. Prognostic factors for locoregional recurrence-free survival (LRRFS) were analyzed.

RESULTS

Between January 2005 and December 2019, 102 patients were included in the study. Their median age was 55 years. The median follow-up duration was 92 months (range; 30-231 months). The excellent response rate after RAI was 42%. The 7-year overall survival, LRRFS, and recurrence-free survival rates were 100%, 75%, and 75%, respectively. Metastatic lymph node size, resection margin status, and post-RAI suppressed thyroglobulin level were the independent prognostic factors for LRRFS.

CONCLUSION

We demonstrated that 75% of patients with PTC with other organ invasions could achieve long-term survival without recurrence after adjuvant RAI. Future development of effective treatment strategies for large metastatic lymph nodes, gross residual tumors, and high serum thyroglobulin levels is warranted.

External beam radiotherapy for thyroid cancer: Patients, complications, and survival

BACKGROUND

Patterns of utilization of external beam radiation therapy (EBRT) in thyroid cancer are incompletely described. We characterize therapeutic intent, complications, and survival in thyroid cancer treated with EBRT.

METHODS

In this retrospective study of 105 thyroid cancer patients treated with EBRT at one institution (2008-2018), the primary outcome was overall survival. Secondary outcomes included incomplete treatment, emergency department (ED) visits, weight change, and gastrostomy placement.

RESULTS

Dominant histopathology was differentiated (44%), anaplastic (45%) and poorly-differentiated (11%) disease. EBRT was mainly utilized for locoregional control (differentiated 87%, poorly-differentiated 75%, anaplastic 92%). Palliative EBRT was more common in poorly-differentiated disease (42%). Weight loss was greater in aggressive/advanced disease (differentiated 10 lb, poorly-differentiated 27 lb, anaplastic 18 lb). Anaplastic cancer had higher rates of gastrostomy (34%) and lowest rates of treatment completion (83%). ED encounters were common (differentiated 44%, poorly-differentiated 50%, anaplastic 45%). Gastrostomy was associated with mortality on multivariable analysis in non-anaplastic malignancy.

CONCLUSIONS

EBRT was most frequently administered for locoregional control in thyroid cancer. Despite complications, the majority of patients completed EBRT therapy.

Well-Differentiated Thyroid Cancer: Who Should Get Postoperative Radiation?

BACKGROUND

The mainstay of treatment of well-differentiated thyroid cancer (WDTC) is surgery followed by adjuvant radioactive iodine therapy. Postoperative radiation therapy (PORT) is rarely used.

OBJECTIVE

The aim of our study was to report our experience of patients with WDTC who were selected to receive PORT.

MATERIALS AND METHODS

After Institutional Review Board approval, patients who received PORT were identified from a departmental database of 6259 patients with WDTC treated with primary surgery from 1986 to 2015. We carried out propensity matching to compare outcomes with a cohort of patients who did not receive PORT. The main outcome of interest was central neck recurrence-free probability (CNRFP), while secondary outcomes were lateral neck recurrence-free probability (LNRFP), disease-specific survival (DSS), and overall survival (OS).

RESULTS

From 6259 patients, 32 (0.5%) patients with a median age of 65.2 years received PORT. Tall-cell variant papillary thyroid carcinoma was the most common pathology (45%). Patients who received PORT had no difference in CNRFP compared with patients treated without PORT (10-year CNRFP 88% vs. 73%; p = 0.18). Furthermore, patients who received PORT had superior LNRFP (10-year LNRFP 100% vs. 62%; p = 0.001) compared with the no-PORT cohort. Despite this, patients who received PORT had similar DSS (71% PORT vs. 75% no-PORT) and OS (65% PORT vs. 58% no-PORT group) as the no-PORT cohort.

CONCLUSIONS

Our data show that select patients who received PORT had improved locoregional recurrence-free probability; however, this did not translate into improved DSS and OS. At our institution, we recommend the use of PORT only in highly selected patients with locally advanced primary tumors who are deemed to have a high risk of central neck recurrence for which salvage surgery would result in unacceptable risk to the airway.

Outcomes and Toxicities of Nonmedullary Thyroid Tumors Treated with Proton Beam Radiation Therapy

Purpose

Proton therapy is an emerging therapy for several malignancies owing to its favorable therapeutic ratio. There are very limited data on the use of proton therapy in the management of thyroid carcinoma. Our objective was to review the safety, feasibility, and outcomes of proton therapy for patients with thyroid cancer treated to the head and neck.

Methods

From our institution's proton database from 2012 to 2021, we identified 22 patients with thyroid cancer treated with proton beam therapy. We evaluated outcomes and toxicities.

Results

Median follow-up was 26 months. Of the 22 patients, 50% were female. The mean age was 65 years. Three patients had anaplastic cancer; 13, papillary carcinoma; 2, follicular carcinoma; and 2, poorly differentiated carcinoma. Forty-six percent had T4 disease. Primary targets were the central neck compartment, level VI, and upper mediastinum. Radiation dose was 60 GyRBE adjuvantly, and 70 GyRBE for gross disease (range, 6000-7600 GyRBE). Eight patients underwent upfront adjuvant radiation, and 3 received definitive radiation for unresectable disease upfront. Eleven patients received either salvage or palliative radiation. Fifty-nine percent of patients had extrathyroidal extension, and 64% of patients had gross disease in the neck before treatment. Fifty percent of patients had metastatic disease before treatment. Sixteen patients received concurrent chemotherapy, 63% of these patients received doxorubicin. For all patients, 1-year local regional recurrence (LRR) was 0%, and overall survival (OS) was 90%. Acute grade 3+ toxicities occurred in 27% of patients, the most frequent being dermatitis (27%). Three patients required a percutaneous endoscopic gastrostomy tube after radiation therapy (RT), 2 owing to progression. There were no grade 4+ toxicities.

Conclusions

Proton therapy for thyroid cancer appears feasible and effective with minimal toxicities. Prospective studies comparing proton therapy with intensity-modulated RT, to evaluate the clinical efficacy of using proton therapy to reduce toxicities in patients undergoing radiation for thyroid cancer, are warranted.

In Vitro and In Vivo Effects of the Urokinase Plasminogen Activator Inhibitor WX-340 on Anaplastic Thyroid Cancer Cell Lines

Increased expression of the urokinase-type plasminogen activator (uPA) system is associated with tumor invasion, neo-angiogenesis, and metastatic spread, and has been shown to positively correlate with a poor prognosis in several cancer types, including thyroid carcinomas. In recent years, several uPA inhibitors were found to have anticancer effects in preclinical studies and in some phase II clinical trials, which prompted us to evaluate uPA as a potential therapeutic target for the treatment of patients affected by the most aggressive form of thyroid cancer, the anaplastic thyroid carcinoma (ATC). In this study, we evaluated the in vitro and in vivo effects of WX-340, a highly specific and selective uPA inhibitor, on two ATC-derived cell lines, CAL-62 and BHT-101. The results obtained indicated that WX-340 was able to reduce cell adhesion and invasiveness in a dose-dependent manner in both cell lines. In addition, WX-340 increased uPA receptor (uPAR) protein levels without affecting its plasma membrane concentration. However, this compound was unable to significantly reduce ATC growth in a xenograft model, indicating that uPA inhibition alone may not have the expected therapeutic effects.

Postoperative external beam radiotherapy for locoregional control in iodine refractory differentiated thyroid cancer

Background

The role of postoperative external beam radiotherapy (EBRT) in patients with residual iodine refractory-differentiated thyroid cancer (IR-DTC) is still inconclusive. The aim of this retrospective study was to evaluate locoregional control (LRC) and overall survival (OS), and potential side effects after postoperative EBRT for both microscopic and macroscopic non-radically resected, locally advanced IR-DTC.

Methods

Between 1990 and 2016, 49 patients with locally advanced IR-DTC received EBRT for microscopic (R1; n = 28) or macroscopic (R2; n = 21) locoregional residual disease. For more insight into the added effect of EBRT, we performed an intrapatient sub-analysis in 32 patients who had undergone more than 1 surgical intervention, comparing LRC after primary, curative-intended surgery with LRC after repeated surgery plus EBRT. To estimate LRC and OS, we used Kaplan-Meier curves. From 2007 onward, we prospectively recorded toxicity data in our head and neck cancer database (n = 10).

Results

LRC rates 5 years after EBRT were higher for R1 (84.3%) than for R2 (44.9%) residual disease (P = 0.016). The 5-year OS rate after EBRT was 72.1% for R1 and 33.1% for R2 disease (P = 0.003). In the intrapatient analysis (n = 32), LRC rates were 6.3% 5 years after only initial surgery and 77.9% after repeated surgery with EBRT (P < 0.001). Acute toxicity was limited to grade I and II xerostomia, mucositis, and hoarseness; only one patient developed late grade III dysphagia.

Conclusions

Postoperative EBRT is associated with long-lasting LRC and OS with acceptable toxicity in patients with locally advanced IR-DTC, especially in microscopic residual disease.

Intensity-modulated radiation therapy and doxorubicin in thyroid cancer: A prospective phase 2 trial

BACKGROUND

The use of external-beam radiotherapy for locally advanced nonanaplastic thyroid cancer remains controversial. This prospective study evaluated the efficacy and tolerability of intensity-modulated radiation therapy (IMRT) with or without concurrent chemotherapy in patients with locally advanced thyroid cancer.

METHODS

The authors conducted a nonrandomized phase 2 trial of IMRT with or without concurrent doxorubicin in patients with gross residual or unresectable nonanaplastic thyroid carcinoma (ClinicalTrials.gov identifier NCT01882816). The primary end point was 2-year locoregional progression-free survival (PFS). Secondary end points included overall survival (OS), safety, patient-reported outcomes, and functional outcomes.

RESULTS

Twenty-seven patients were enrolled: 12 (44.4%) with unresectable disease and 15 (55.6%) with gross residual disease. The median follow-up was 45.6 months (interquartile range, 42.0-51.6 months); the 2-year cumulative incidences of locoregional PFS and OS were 79.7% and 77.3%, respectively. The rate of grade 3 or higher acute and late toxicities was 33.4%. There were no significant functional differences 12 months after treatment (assessed objectively by the modified barium swallow study). Patient-reported quality of life in the experimental group was initially lower but returned to the baseline after 6 months and improved thereafter. In a post hoc analysis, concurrent chemotherapy with intensity-modulated radiation therapy (CC-IMRT) resulted in significantly less locoregional failure at 2 years (no failure vs 50%; P = .001), with higher rates of grade 2 or higher acute dermatitis, mucositis, and dysphagia but no difference in long-term toxicity, functionality, or patient-reported quality of life.

CONCLUSIONS

In light of the excellent locoregional control rates achieved with CC-IMRT and its acceptable toxicity profile as confirmed by functional assessments and patient-reported outcomes, CC-IMRT may be preferred over IMRT alone.

[Efficacy and tolerance of salvage curative radiotherapy for patients with cervical relapse of differentiated thyroid carcinoma]

PURPOSE

Radiation therapy is often the last resource treatment for cervical relapse in iodine refractory differentiated thyroid cancer. We present locoregional control data in patients with cervical relapse treated with curative intent radiation therapy with or without concomitant carboplatin.

MATERIAL AND METHODS

This monocentric retrospective study gathered data on patients with differentiated thyroid carcinoma - vesicular or papillary - in relapse after thyroidectomy who received a curative intent cervical radiation therapy. Locoregional progression free survival (LRPFS), progression free survival (PFS), overall survival (OS) were gathered as well as acute and chronic adverse events assessed with the CTCAE v4.

RESULTS

Thirty-nine patients were consecutively included between 2005 and 2019. The median follow-up was 36.6months. Fifteen patients (38%) had a locoregional relapse, locoregional control at 2years was 66.7%. The median LRPFS was 48months [32.9-not reached] and the median overall survival 49months [38.8-not reached]. In multivariate analysis, initial incomplete resection was associated with poorer OS (HR: 24.39 [3.57-166.78], P=0.00113) and LRPFS (HR: 33.91 [4.46-257.61], P=0.00066), extra nodal spread was associated with poorer LRPFS (HR: 13.45 [1.81-99,76], P=0.011). ECOG performance status was associated with OS (HR: 5.11 [1.57-16.66], P=0.00688). Carboplatin association with radiation therapy was not associated with improved survivals (OS: P=0.34, LRPFS: P=0.84). The rate of acute grade 3 toxicities was 14%.

CONCLUSION

Salvage cervical radiation therapy was associated with a locoregional control of 66.7% at 2years with a reasonable toxicity rate. Carboplatin association with radiation therapy did not improve locoregional control nor overall survival in comparison with radiotherapy alone.

Initial Experience with Proton Beam Therapy for Differentiated Thyroid Cancer

Purpose

External beam radiotherapy is used in a subset of high-risk patients with differentiated thyroid cancer (DTC). Recurrent, radioactive iodine (RAI)-refractory DTC carries a poor prognosis. We report our initial experience of intensity-modulated proton therapy (IMPT) for recurrent, RAI-refractory DTC.

Patients and Methods

Fourteen patients with recurrent, RAI-refractory DTC were consecutively treated with IMPT from November 2016 to March 2020 at our multisite institution. Patient, tumor, and treatment characteristics were recorded. Overall survival and local-regional recurrence-free survival were recorded and estimated using the Kaplan-Meier method. Acute and late treatment-related toxicities were recorded based on the Common Terminology Criteria for Adverse Events version 5.0. Patients completed the European Organization for Research and Treatment of Cancer Quality of Life Head and Neck Module at baseline and after IMPT. Eleven patients were included in the final analysis.

Results

Median follow-up was 8 months (range, 3-40) for all patients. Median age at treatment with IMPT was 64 years (range, 40-77), and the majority were men (64%). Recurrent histologies included papillary (55%), Hurthle cell (36%), and poorly differentiated (9%) carcinoma; 1 patient had tall cell variant. Concurrent chemotherapy was not administered for any patient in this cohort. At 8 months, all patients were alive without local-regional failure. Acute grade 3 toxicities were limited to 1 patient with dysphagia, requiring feeding tube placement. Two patients experienced late grade 3 esophageal stenosis requiring dilation. There were no grade 4 or 5 toxicities. There were no differences in pretreatment versus posttreatment patient-reported outcomes in terms of dysphagia or hoarseness.

Conclusion

In our early experience, IMPT provided promising local-regional control for recurrent, RAI-refractory DTC. Further study is warranted to evaluate the long-term efficacy and safety of IMPT in this patient population.

IGF2 is a potential factor in RAI-refractory differentiated thyroid cancer

Differentiated thyroid cancer (DTC) is the most frequent endocrine tumor with a good prognosis after primary treatment in most cases. By contrast, 30–40% of patients with metastatic DTC are unresponsive to ¹³¹I radioactive iodide (RAI) treatment due to tumor dedifferentiation. Currently, underlying molecular mechanisms of dedifferentiation remain elusive and predictive biomarkers are lacking. Therefore, the present study aimed to identify molecular biomarkers in primary tumors associated with RAI refractoriness. A retrospective cohort was gathered consisting of RAI-sensitive patients with DTC and RAI-refractory patients with poorly DTC. In all patients, extensive intratumoral mutation profiling, gene fusions analysis, telomerase reverse transcriptase (TERT) promoter mutation analysis and formalin-fixed paraffin-embedded-compatible RNA sequencing were performed. Genetic analyses revealed an increased mutational load in RAI-refractory DTC, including mutations in AKT1, PTEN, TP53 and TERT promoter. Transcriptomic analyses revealed profound differential expression of insulin-like growth factor 2 (IGF2), with up to 100-fold higher expression in RAI-refractory DTC compared with in RAI-sensitive DTC cases. ELISA revealed significant lower IGF2 plasma concentrations after surgery and subsequent ¹³¹I RAI therapy in patients with DTC compared with pretreatment baseline. Overall, the current findings suggested that the tumor-promoting growth factor IGF2 may have a potential role in acquiring RAI refractoriness.

Digoxin treatment reactivates in vivo radioactive iodide uptake and correlates with favorable clinical outcome in non-medullary thyroid cancer

PURPOSE

Non-medullary thyroid cancer (NMTC) treatment is based on the ability of thyroid follicular cells to accumulate radioactive iodide (RAI). However, in a subset of NMTC patients tumor dedifferentiation occurs, leading to RAI resistance. Digoxin has been demonstrated to restore iodide uptake capacity in vitro in poorly differentiated and anaplastic NMTC cells, termed redifferentiation. The aim of the present study was to investigate the in vivo effects of digoxin in TPO-Cre/LSL-Braf^V600E mice and digoxin-treated NMTC patients.

METHODS

Mice with thyroid cancer were subjected to 3D ultrasound for monitoring tumor growth and ¹²⁴I PET/CT for measurement of intratumoral iodide uptake. Post-mortem analyses on tumor tissues comprised gene expression profiling and measurement of intratumoral autophagy activity. Through PALGA (Dutch Pathology Registry), archived tumor material was obtained from 11 non-anaplastic NMTC patients who were using digoxin. Clinical characteristics and tumor material of these patients were compared to 11 matched control NMTC patients never treated with digoxin.

RESULTS

We found that in mice, tumor growth was inhibited and ¹²⁴I accumulation was sustainably increased after short-course digoxin treatment. Post-mortem analyses revealed that digoxin treatment increased autophagy activity and enhanced expression of thyroid-specific genes in mouse tumors compared to vehicle-treated mice. Digoxin-treated NMTC patients exhibited significantly higher autophagy activity and a higher differentiation status as compared to matched control NMTC patients, and were associated with favourable clinical outcome.

CONCLUSIONS

These in vivo data support the hypothesis that digoxin may represent a repositioned adjunctive treatment modality that suppresses tumor growth and improves RAI sensitivity in patients with RAI-refractory NMTC.

Prognostic Impact of Histologic Grade for Papillary Thyroid Carcinoma

BACKGROUND

While numerous factors affect prognosis in papillary thyroid carcinoma (PTC), the comparative impact of histologic grade has not been well described. Moreover, indications for external beam radiation therapy (EBRT) remain imprecise. We evaluate clinicopathologic characteristics and outcomes for PTC stratified by grade.

METHODS

We profiled histologic grade for PTC (well differentiated, moderately differentiated, poorly differentiated) via hospital (National Cancer Database) and population-based (Surveillance, Epidemiology, and End Results) registries. Cox regression was used to adjust for clinicopathologic covariates. Statistical interactions between subtypes and the effect of EBRT on survival were assessed.

RESULTS

Collectively, worsening clinicopathologic factors (age, tumor size, extrathyroidal extension, nodal spread, M1 disease) and outcomes (disease-free survival, overall survival) correlated with less differentiated state, across all histologic grades (p < 0.001). Multivariable analysis showed escalating hazard with loss of differentiation relative to well-differentiated PTC (moderately differentiated hazard ratio [HR] 1.21, 95% confidence interval [CI] 1.04-1.41, p = 0.02; poorly differentiated HR 2.62, 95% CI 2.23-3.08, p < 0.001). Correspondingly, greater survival benefit was associated with EBRT for poorly differentiated cases (HR 0.36, 95% CI 0.18-0.72, p = 0.004). This finding was upheld after landmark analysis to address potential immortal time bias (HR 0.37, 95% CI 0.17-0.80, p = 0.01).

CONCLUSIONS

Worsening histologic grade in PTC is independently associated with parallel escalation in mortality risk, on a scale approximating or surpassing established thyroid cancer risk factors. On preliminary analysis, EBRT was associated with improved survival in the most aggressive or least differentiated subvariants. Further investigation is warranted to examine the efficacy of EBRT for select poorly differentiated thyroid carcinomas.

The revised clinical practice guidelines on the management of thyroid tumors by the Japan Associations of Endocrine Surgeons: Core questions and recommendations for treatments of thyroid cancer

The Japan Associations of Endocrine Surgeons has developed the revised version of the Clinical Practice Guidelines for Thyroid Tumors. This article describes the guidelines translated into English for the 35 clinical questions relevant to the therapeutic management of thyroid cancers. The objective of the guidelines is to improve health-related outcomes in patients with thyroid tumors by enabling users to make their practice evidence-based and by minimizing any variations in clinical practice due to gaps in evidential knowledge among physicians. The guidelines give representative flow-charts on the management of papillary, follicular, medullary, and anaplastic thyroid carcinoma, along with recommendations for clinical questions by presenting evidence on the relevant outcomes including benefits, risks, and health conditions from patients' perspective. Therapeutic actions were recommended or not recommended either strongly (◎◎◎ or XXX) based on good evidence (😊)/good expert consensus (+++), or weakly (◎, ◎◎ or X, XX) based on poor evidence (😣)/poor expert consensus (+ or ++). Only 10 of the 51 recommendations given in the guidelines were supported by good evidence, whereas 35 were supported by good expert consensus. While implementing the current guidelines would be of help to achieve the objective, we need further clinical research to make our shared decision making to be more evidence-based.

Locally unresectable differentiated thyroid cancer: outcomes and perspectives

PURPOSE

Differentiated thyroid cancer (DTC) patients with an unresectable primary tumor cannot benefit from curative surgery, and radioiodine treatment for locoregional and distant disease is not possible with the thyroid gland still in place. Due to local invasion, these patients cannot be included in clinical trials, so that treatment options are limited. The aim of this study was to describe the characteristics and the prognosis of patients with these locally unresectable DTC.

PATIENTS AND METHODS

A retrospective and multicentric analysis of consecutive cases of unresectable DTC diagnosed between 2000 and 2015 was performed.

RESULTS

The study population consisted in 22 patients, 13 females (59%); median age: 77 years (range: 52-91). Thyroid tumors were papillary in six, follicular in seven, Hürthle cell in one and poorly differentiated in eight patients. Patients were treated with external beam radiation therapy (EBRT) (57%), locoregional therapy of distant metastases (41%), cytotoxic chemotherapy (38%) and tyrosine kinase inhibitors (TKIs) (33%). TKI treatment resulted in median disease control duration of 7 months with a grade 3-4 toxicity rate of 44%. Only one patient had a total thyroidectomy after neo-adjuvant EBRT. The 1, 3 and 5-year cumulative survival rate was 81%, 27.7% and 21.5%, respectively. The cause of death was DTC in 11 cases (local progression in 7), and to other causes in 7 cases; no patient died from treatment toxicity.

CONCLUSIONS

Clinical trials and approved treatments are lacking for unresectable DTC. TKI treatment may allow prolonged disease control with acceptable toxicity.

Intensity-Modulated Radiation Therapy With or Without Concurrent Chemotherapy in Nonanaplastic Thyroid Cancer with Unresectable or Gross Residual Disease

BACKGROUND

Differentiated thyroid cancer typically has an indolent clinical course but can cause significant morbidity by local progression. Oncologic surgical resection can be technically difficult due to the proximity to critical normal structures in the neck. Our objective was to review the safety, feasibility, and outcomes of definitive-intent intensity-modulated radiation therapy (IMRT) and to analyze whether patients receiving concurrent chemotherapy (CC-IMRT) had higher rates of disease control and survival over IMRT alone in patients with unresectable or gross residual disease (GRD).

METHODS

Eighty-eight patients with GRD or unresectable nonanaplastic, nonmedullary thyroid cancer treated with definitive-intent IMRT between 2000 and 2015 were identified. Local progression-free survival (LPFS), distant metastasis-free survival (DMFS), and overall survival (OS) were evaluated using the Kaplan-Meier method. Univariate and multivariate analyses using cox regression were used to determine the impact of clinical conditions and treatment on LPFS, DMFS, and OS.

RESULTS

Of the 88 patients identified, 45 (51.1%) were treated CC-IMRT and 43 (48.9%) were treated with IMRT alone. All patients treated with CC-IMRT received weekly doxorubicin (10 mg/m²). The median follow-up among surviving patients was 40.3 months and 29.2 months for all patients. The LPFS at 4 years was 77.3%. Patients receiving CC-IMRT had higher LPFS compared with IMRT alone (CC-IMRT 85.8% vs. IMRT 68.8%, p = 0.036). The 4-year OS was 56.3% for all patients. Patients treated with CC-IMRT had higher OS compared to patients treated with IMRT alone (CC-IMRT 68.0% vs. IMRT 47.0%, p = 0.043). On multivariate analysis, receipt of concurrent chemotherapy was associated with a lower risk of death (HR 0.395, p = 0.019) and lower risk of local failure (HR 0.306, p = 0.042). Grade 3+ acute toxicities occurred in 23.9% of patients, the most frequent being dermatitis (18.2%) and mucositis (9.1%). 17.1% of patients required a percutaneous endoscopic gastrostomy (PEG) tube during or shortly after completion of RT, with 10.1% of patients needing a PEG more than 12 months after therapy. The rates of acute and late toxicities were not statistically higher in the CC-IMRT cohort, although trends towards higher toxicity in the CC-IMRT were present for dermatitis and PEG requirement.

CONCLUSIONS

IMRT is a safe and effective means to achieve local control in patients with unresectable or incompletely resected nonanaplastic, nonmedullary thyroid cancer. Concurrent doxorubicin was not associated with worse toxicity and should be considered in these patients given its potential to improve local control and overall survival.

New perspectives in the diagnosis of thyroid follicular lesions

Thyroid nodules are very common, affecting 19%-67% of the adult population. However, about 10% of them harbor a malignant lesion. Consequently, the first aim in their clinical evaluation is to exclude malignancy. Fine-needle aspiration cytology (FNAC) represents the main diagnostic tool for the evaluation of thyroid nodules. However, FNAC has a main diagnostic limit, namely cellular atypias of indeterminate significance, which require surgical excision and histological examination to differentiate benign from malignant lesions. Histology reports show that approximately 80% of these patients harbor a benign lesion. Therefore, in order to reduce unnecessary thyroidectomy, over the last years, the cytological classification of thyroid nodules has been revised and a number of new instrumental and molecular approaches have been proposed. In the present article, we will attempt to summarize the most recent cytological, molecular and echographic strategies to enhance the diagnostic accuracy of preoperative thyroid follicular lesions. In particular, we will discuss the new cytological classifications from the Bethesda System for Reporting Thyroid Cytopathology (BSRTC), the British Thyroid Association-Royal College of Pathologists (PTA-RCPath) and the new Italian Society for Anatomic Pathology and Cytology (SIAPEC 2014. We will review molecular tests evaluated to ameliorate follicular lesion diagnosis as well as the clinical utility of the new echographic Thyroid Imaging Reporting and Data System (TI-RADS) score.

18F-FDG Pet-Guided External Beam Radiotherapy in Iodine-Refractory Differentiated Thyroid Cancer: A Pilot Study

Introduction

To evaluate the clinical response rate after a postoperative ¹⁸F-FDG PET/CT guided external beam radiotherapy (EBRT) in Iodine-refractory differentiated thyroid cancer.

Material and Methods

Patients with thyroid cancer locally recurrent after total thyroidectomy plus metabolic radiotherapy and treated with radical EBRT were included. Inclusion criteria were detectable thyroglobulin (Tg), negative postmetabolic radiotherapy whole body scintigraphy, and no surgical indications. The pretreatment ¹⁸F-FDG PET/CT resulted positive in all cases (loggia, lymph nodes, and lung). EBRT was delivered with IMRT-SIB technique. A ¹⁸F-FDG PET/CT revaluation and Tg dosage were performed 3 months after the treatment.

Results

Sixteen consecutive patients were included in this analysis (median follow-up: 6–44 months). Post-EBRT ¹⁸F-FDG PET/CT showed CR in 43.7%, PR in 31.2%, SD in 25.0% patients, and PD due to lung metastases in 12.5%. Overall response rate was 75.0% (CI 95%: 41.4–93.3%). Tg levels decreased in 75.0% with a median Δ of 68.0%. Two-year PFS and OS rates were 80.0% and 93.0%, respectively. Acute G3 toxicity occurred in 18.7% and late G2 toxicity in 12.5%.

Conclusions

  ¹⁸F-FDG PET/CT was useful in target definition for radiotherapy planning, identifying positive areas not detected with ¹³¹I scintigraphy. IMRT based EBRT was feasible and our results encourage future prospective studies. This clinical trial is registered with ID: NCT03191643.

Pathological processes and therapeutic advances in radioiodide refractory thyroid cancer

While in most patients with non-medullary thyroid cancer (TC), disease remission is achieved by thyroidectomy and ablation of tumor remnants by radioactive iodide (RAI), a substantial subgroup of patients with metastatic disease present tumor lesions that have acquired RAI resistance as a result of dedifferentiation. Although oncogenic mutations in BRAF, TERT promoter and TP53 are associated with an increased propensity for induction of dedifferentiation, the role of genetic and epigenetic aberrations and their effects on important intracellular signaling pathways is not yet fully elucidated. Also immune, metabolic, stemness and microRNA pathways have emerged as important determinants of TC dedifferentiation and RAI resistance. These signaling pathways have major clinical implications since their targeting could inhibit TC progression and could enable redifferentiation to restore RAI sensitivity. In this review, we discuss the current insights into the pathological processes conferring dedifferentiation and RAI resistance in TC and elaborate on novel advances in diagnostics and therapy to improve the clinical outcome of RAI-refractory TC patients.

CASTLE Thyroid Tumor: A Case Report and Literature Review

Carcinoma showing thymus-like differentiation is a rare tumor of the thyroid gland, which is structurally similar to thymic tissue. Overall, it has a favorable prognosis. Radiotherapy has been shown to be an effective local treatment, but there have been reports of distant recurrence. It has been suggested that adding chemotherapy may decrease the risk of recurrence. Here, we present a case report of a patient with a large tumor and extrathyroidal extension. The patient was treated with surgery, radiotherapy, and cisplatin with acceptable toxicity. The patient is free of locally recurrent or distant disease at 3 years.

Comprehensive management of recurrent thyroid cancer: An American Head and Neck Society consensus statement: AHNS consensus statement

This American Head and Neck Society (AHNS) consensus statement focuses on the detection and management of recurrent thyroid cancer. This document describes the radiologic approach to defining structural recurrent disease and the operative and nonoperative rationale in addressing identified structural disease to create equipoise in the personalized treatment strategy for the patient. The recommendations of this AHNS multidisciplinary consensus panel of the American Head and Neck Society are intended to help guide all multidisciplinary clinicians who diagnose or manage adult patients with thyroid cancer. The consensus panel is comprised of members of the American Head and Neck Society and its Endocrine Surgical Committee, and there is representation from medical endocrinology and both national and international surgical representation drawn from general/endocrine surgery and otolaryngology/head and neck surgery. Authors provided expertise for their respective sections, and consensus recommendations were made regarding the evaluation and treatment of recurrent thyroid cancer. Evidence-based literature support is drawn from thyroid cancer studies, recurrent thyroid cancer studies, and American Thyroid Association (ATA) guidelines. The manuscript was then distributed to members of the American Head and Neck Society Endocrine Committee and governing counsel for further feedback. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1862-1869, 2016.

External beam radiotherapy in thyroid carcinoma: clinical review and recommendations of the AIRO "Radioterapia Metabolica" Group

The therapeutic approach to thyroid carcinoma usually involves surgery as initial treatment. The use of external beam radiotherapy (EBRT) is limited to high-risk patients and depends on clinical stage and histologic type. Different behavior patterns and degrees of aggressiveness of thyroid carcinomas require different management for differentiated, medullary, and anaplastic carcinoma. However, the role of EBRT is an issue of debate. Most clinical studies are retrospective and based on single-institution experiences. In this article, we review the main literature and give recommendations for the use of EBRT in thyroid carcinoma on behalf of the "Radioterapia Metabolica" Group of the Italian Radiation Oncology Association.

Management of Invasive Differentiated Thyroid Cancer

BACKGROUND

Invasive disease is a poor prognostic factor for patients with differentiated thyroid cancer (DTC). Uncontrolled central neck disease is a common cause of distressing death for patients presenting in this manner. Advances in assessment and management of such cases have led to significant improvements in outcome for this patient group. This article reviews the patterns of invasion and a contemporary approach to investigation and treatment of patients with invasive DTC.

SUMMARY

Aerodigestive tract invasion is reported in around 10% of case series of DTC. Assessment should include not only clinical history and physical examination with endoscopy as indicated, but ultrasound and contrast-enhanced cross-sectional imaging. Further studies including positron emission tomography should be considered, particularly in recurrent cases that are radioactive iodine (RAI) resistant. Both the patient and the extent of disease should be carefully assessed prior to embarking on surgery. The aim of surgery is to resect all gross disease. When minimal visceral invasion is encountered early, "shave" procedures are recommended. In the setting of transmural invasion of the airway or esophagus, however, full thickness excision is required. For intermediate cases in which invasion of the viscera has penetrated the superficial layers but is not evident in the submucosa, opinion is divided. Early reports recommended an aggressive approach. More recently authors have tended to recommend less aggressive resections with postoperative adjuvant therapies. The role of external beam radiotherapy continues to evolve in DTC with support for its use in patients considered to have RAI-resistant tumors.

CONCLUSIONS

Patients with invasive DTC require a multidisciplinary approach to investigation and treatment. With detailed assessment, appropriate surgery, and adjuvant therapy when indicated, this patient group can expect durable control of central neck disease, despite the aggressive nature of their primary tumors.

Grouping of Metastatic Thyroid Carcinoma by Molecular Imaging Features to Allow for Individualized Treatment, with Emphasis on the TENIS Syndrome

The process of radioiodine ((131)I) refractoriness, dedifferentiation, and development of thyroglobulin elevation and negative iodine scintigraphy (TENIS) syndrome in metastatic differentiated thyroid carcinoma (DTC) could be viewed as a disease continuum rather than a single event or an all-or-none phenomenon. In this report, the important role of molecular functional imaging in systematically exploring the disease biology and course of metastatic DTC is presented. Making this role the base, this report proposes a novel clinical classification for TENIS syndrome using molecular functional imaging. Such an endeavor, in our view, would aid in classification into subgroups and development of an individualized treatment strategy for patients with metastatic DTC. Case illustrations are presented that substantiate this viewpoint, including the value of combined assessment in selected cases and the requirement of a multipronged treatment approach for certain case scenarios. In addition to multiple other considerations, we believe that molecular functional imaging-based characterization of metastatic lesions could evolve as an important determinant for defining the optimal treatment strategy in patients with metastatic DTC, making the clinical management more rational and scientific.

Does radiation dose matter in thyroid cancer?: Patterns of local-regional failure in recurrent and metastatic well-differentiated thyroid cancers treated with dose-painted intensity-modulated radiation therapy

INTRODUCTION

Due to complex multimodal treatments and a lengthy natural history of disease, the impact of radiation therapy for well-differentiated thyroid cancer (WDTC) is challenging to evaluate. We analysed the effect of dose escalation, as enabled by intensity-modulated radiation therapy (IMRT), on preventing local-regional failure (LRF) of microscopic and macroscopic WDTC.

METHOD

We performed a retrospective review of WDTC patients treated with IMRT from 1998-2011. Diagnostic imaging demonstrating first LRF was registered to the simulation CT containing the treated radiation isodose volumes. Areas of disease progression were contoured and the relationships of LRFs with isodose volumes were recorded.

RESULTS

Thirty patients had a median follow-up of 56 months (range = 1-139). Seventeen (57%) had gross residual, five (17%) had microscopic residual and eight (27%) had clear margins at the time of IMRT. Nine patients (30%) developed LRF, at a median time of 44 months (range = 0-116). Of these, six (67%) had been radiated to gross disease and one (11%) had microscopic residual. In the seven analysable cases, only one (14%) LRF occurred within the 70 Gy isodose volume. Marginal LRFs were: four (57%) outside 70 Gy, one (14%) outside 60 Gy and one (14%) outside 50 Gy. All but one recurrence (86%) occurred in the perioesophageal region.

CONCLUSIONS

Local-regional failure was seen most in patients who had gross disease at the time of IMRT, almost always occurred outside of the 70 Gy volume and was frequently in the area of oesophageal sparing. Meticulous surgical dissection, especially in the perioesophageal region, should be prioritised to prevent long-term LRF.

Novel Approaches to Thyroid Cancer Treatment and Response Assessment

The incidence of thyroid cancer has been increasing. After total thyroidectomy of well-differentiated thyroid tumors with intermediate- or high-risk features on pathology, radioiodine remains one of the mainstays of therapy for both thyroid remnant ablation as well as for treatment of metastatic disease. SPECT/CT, a relatively new modality, has been shown to play a pivotal role predominantly in the post-therapy setting by changing the risk stratification of patients with thyroid cancer. In the case of radioiodine treatment failure, FDG-PET/CT may provide prognostic information based on extent and intensity of metabolically active metastatic sites as well as serve as an important imaging test for response assessment in patients treated with chemotherapy, targeted therapies, or radiotherapy, thereby affecting patient management in multiple ways. The role of newer redifferentiation drugs has been evaluated with the use of I-124 PET/CT.

2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: The American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer

BACKGROUND

Thyroid nodules are a common clinical problem, and differentiated thyroid cancer is becoming increasingly prevalent. Since the American Thyroid Association's (ATA's) guidelines for the management of these disorders were revised in 2009, significant scientific advances have occurred in the field. The aim of these guidelines is to inform clinicians, patients, researchers, and health policy makers on published evidence relating to the diagnosis and management of thyroid nodules and differentiated thyroid cancer.

METHODS

The specific clinical questions addressed in these guidelines were based on prior versions of the guidelines, stakeholder input, and input of task force members. Task force panel members were educated on knowledge synthesis methods, including electronic database searching, review and selection of relevant citations, and critical appraisal of selected studies. Published English language articles on adults were eligible for inclusion. The American College of Physicians Guideline Grading System was used for critical appraisal of evidence and grading strength of recommendations for therapeutic interventions. We developed a similarly formatted system to appraise the quality of such studies and resultant recommendations. The guideline panel had complete editorial independence from the ATA. Competing interests of guideline task force members were regularly updated, managed, and communicated to the ATA and task force members.

RESULTS

The revised guidelines for the management of thyroid nodules include recommendations regarding initial evaluation, clinical and ultrasound criteria for fine-needle aspiration biopsy, interpretation of fine-needle aspiration biopsy results, use of molecular markers, and management of benign thyroid nodules. Recommendations regarding the initial management of thyroid cancer include those relating to screening for thyroid cancer, staging and risk assessment, surgical management, radioiodine remnant ablation and therapy, and thyrotropin suppression therapy using levothyroxine. Recommendations related to long-term management of differentiated thyroid cancer include those related to surveillance for recurrent disease using imaging and serum thyroglobulin, thyroid hormone therapy, management of recurrent and metastatic disease, consideration for clinical trials and targeted therapy, as well as directions for future research.

CONCLUSIONS

We have developed evidence-based recommendations to inform clinical decision-making in the management of thyroid nodules and differentiated thyroid cancer. They represent, in our opinion, contemporary optimal care for patients with these disorders.

External-beam radiotherapy for differentiated thyroid cancer locoregional control: A statement of the American Head and Neck Society

The use of external-beam radiotherapy (EBRT) in differentiated thyroid cancer (DTC) is debated because of a lack of prospective clinical data, but recent retrospective studies have reported benefits in selected patients. The Endocrine Surgery Committee of the American Head and Neck Society provides 4 recommendations regarding EBRT for locoregional control in DTC, based on review of literature and expert opinion of the authors. (1) EBRT is recommended for patients with gross residual or unresectable locoregional disease, except for patients <45 years old with limited gross disease that is radioactive iodine (RAI)-avid. (2) EBRT should not be routinely used as adjuvant therapy after complete resection of gross disease. (3) After complete resection, EBRT may be considered in select patients >45 years old with high likelihood of microscopic residual disease and low likelihood of responding to RAI. (4) Cervical lymph node involvement alone should not be an indication for adjuvant EBRT.