Treatment approach, surveillance, and outcome of well-differentiated thyroid cancer in childhood and adolescence

Mapping the lymph node metastasis landscape: A bibliometric Odyssey of papillary thyroid carcinoma publications (2012-2022)

Objective

Lymph node metastasis in papillary thyroid carcinoma (PTC) has become an area of great interest in the study of thyroid diseases. The aim of this study was to elucidate the research trends and impact of lymph node metastasis of PTC in the study of thyroid diseases through a comprehensive bibliometric analysis.

Methods

We conducted an extensive bibliometric review of the literature on lymph node metastasis in PTC using the Web of Science Core Database (WOSCC), which included approximately 3292 publications from 2012 to 2022. Data analysis and visualization were performed, using advanced bibliometric tools including VOSviewer, CiteSpace, and bibliometrix R software packages.

Results

A total of 3292 publications from 81 one countries were identified. The analysis showed a pattern of growth in the number of publications per year from 2012 to 2022, with China having the highest number of papers. Outstanding contributions were made by China, Korea, USA, Italy and Japan, with Thyroid being the most important journal. The author who published the most papers was Jingqiang Zhu. The institutions that published the most papers were Shanghai Jiao Tong University and Yonsei University. The analysis found that prognosis, recurrence, and ultrasound were the keywords with the highest frequency of occurrence in addition to those related to the title of this article.

Conclusion

Our bibliometric analysis outlines the current state of research on lymph node metastasis in PTC, highlighting significant contributions, trends, and future research directions.

Predictive risk factors for distant metastasis in pediatric differentiated thyroid cancer from Saudi Arabia

Background

Despite their excellent prognosis, children and young adults (CAYA) with differentiated thyroid cancer (DTC) tend to have more frequent occurrence of distant metastasis (DM) compared to adult DTC. Data about DM in CAYA from Middle Eastern ethnicity is limited.

Methods

Medical records of 170 patients with DTC ≤18 years were retrospectively reviewed. Clinico-pathological factors associated with lung metastasis in CAYA, their clinical presentation and outcome were analyzed. Rick factors related to distant metastasis-free survival (DMFS) for the whole cohort were evaluated.

Results

DM was observed in 27 patients and all were lung metastasis. Lung metastasis was significantly associated with younger age (≤15 years), extrathyroidal extension (ETE), multifocal tumors, bilaterality, presence of lymph node (LN) disease and high post-operative stimulated thyroglobulin (sTg). Highest negative predictive values were seen with low post-operative sTg (97.9%), absence of LN disease (93.8%), absence of ETE (92.2%) and age older than 15 years (92.9%). Post-therapy whole body scan (WBS) identified most of the lung metastasis (21 of 27; 77.8%). Upon evaluating patients response according to ATA guidelines, excellent response was seen in only one patient, while biochemical persistence and structural persistence were seen in 11.1% (3/27) and 77.8% (21/27), respectively. Elevated post-operative sTg (>10ng/ml) was the only risk factor found to be significantly associated with both biochemical persistence (with or without structural persistence (p = 0.0143)) and structural persistence (p = 0.0433). Cox regression analysis identified age and post-operative sTg as independent risk factors related to DMFS. Based on these two risk factors for DMFS, patients were divided into 3 groups: low risk (no risk factors), intermediate risk (1 risk factor) and high risk (both risk factors). 20-year DMFS rates in the low-, intermediate- and high-risk groups were 100.0%, 81.3% and 23.7% respectively (p < 0.0001).

Conclusion

Higher suspicion for metastatic pediatric DTC should be considered in patients who are young, have LN disease, extrathyroidal extension and elevated post-operative sTg. Persistent disease, despite therapy, is very common and it appears to be related to post-operative sTg level. Hence, risk adaptive management is desirable in CAYA with DTC.

Differentiated Thyroid Cancer in Adolescents: Single Center Experience and Considerations for Surgical Management and Radioiodine Treatment

Objective

Differentiated thyroid cancer (DTC) in adolescents rare but with a favorable outcome, despite higher rates of cervical lymph node and pulmonary metastasis compared to adults. The aim of this study was to critically evaluate treatment of adolescents with DTC at a single center.

Methods

Patients receiving postoperative radioiodine treatment (RAIT) for DTC between 2005 and 2020 at our institution were screened to identify adolescents according to the World Health Organization definition (10-19 years of age). Demographics, clinico-pathological characteristics, treatment and outcome were analyzed.

Results

Among 1,897 DTC patients, 23 (1.3%) were adolescents with a median (range) age of 16 (10-18) years. The female to male ratio was 3.6:1. Sixty percent had classic papillary thyroid cancer, with follicular variant in 40%, which was higher than previously reported (15-25%) for this age group. pT-status was pT1 in 9 (39.2%), pT2 in 8 (34.8%), pT3 in 3 (13%) and pT4 in 3 (13%) patients. In 19 (82.6%) patients, central lymphadenectomy was performed and metastasis was seen in 57%. All patients received RAIT with initial activities of 1.2 (n=1, 4.3%), 2 (n=12, 52.2%) or 3.7 GBq (n=10, 43.5%). Eighteen (78.2%) patients were free of biochemical and radiologic disease at a median follow-up of 60.7 months. Second-line surgery for lymph node relapse was necessary in 3 (13%) cases. There was one disease-associated death.

Conclusion

Despite high rates of metastasis, most patients were cured, and second-line surgery was rarely required. Further prospective studies are needed to determine whether less aggressive surgical management or omitting adjuvant RAIT are feasible in patients with limited stages at diagnosis.

Long-term prognostic analysis of children and adolescents with differentiated thyroid carcinoma based on therapeutic response to initial radioiodine therapy

Background

The clinical features and prognosis of children and adolescents with differentiated thyroid carcinoma (caDTC) are different from that of adults. Postoperative radioiodine therapy (RIT) was recommended for some intermediate and high risk caDTC patients. The objective of this study was to evaluate the long-term prognosis of pediatric caDTC patients with different responses to initial RIT and to explore the related influencing factors.

Methods

All subjects were assigned to no clinical evidence of disease (NED) group, biochemical persistent disease (BPD) group, or structural/functional persistent disease (S/FPD) group based on the therapeutic response to initial RIT. Then, disease status was evaluated in all three groups at the last follow-up using ATA guidelines. Meanwhile, disease-free survival (DFS) for NED group and the progression-free survival (PFS) for the BPD and S/FPD groups were also assessed.

Results

117 subjects were divided into NED group (n=29), BPD group (n=48) and S/FPD group (n=34) after initial RIT. At the last follow-up, excellent response (ER), indeterminate response (IDR), biochemically incomplete response (BIR) and structurally incomplete response (SIR) rates were 93.10%, 6.90%, 0% and 0% in NED group; 29.17%, 25.00%, 43.75% and 2.08% in BPD group; and 11.77%, 2.94%, 0%, and 85.29% in S/FPD group. The 5-year DFS rate in NED group was 95.5%. The 5-year PFS rates in BPD and S/FPD groups were 79.2% and 48.6%, respectively. For children with structural or functional lesions, longer PFS were found in male children with 131I-avid lesions, and post-operative stimulated serum thyroglobulin (sti-Tg) < 149.80 ng/ml.

Conclusion

The response to initial RIT could be helpful for defining subsequent treatment and follow-up strategies for caDTC patients. Post-operative sti-Tg and 131I-avidity of lesions are correlated with PFS.

Risk factors for the lateral cervical lymph node metastasis of papillary thyroid carcinoma: A clinical study

Currently, there is a lack of evidence-based risk factors for the lateral cervical lymph node metastasis of papillary thyroid carcinoma (PTC). Thus, the risk factors and recurrence rate of lateral cervical lymph node metastasis were investigated in the present study for patients with PTC who underwent initial radical surgery. The data of 274 patients with PTC who underwent initial radical surgery over a 10-year period from January, 2009 to December, 2018 were retrospectively analyzed. By applying univariate analysis, lymphovascular invasion, venous invasion, extrathyroidal infiltration, paratracheal lymph node metastasis and tumor size were designated as significant risk factors for lateral cervical lymph node metastasis. As regards multivariate analysis, paratracheal lymph node metastasis and tumor size were identified as independent risk factors. The recurrence rate was higher in patients presenting with lateral cervical lymph node metastasis, and the disease-free survival rate was significantly lower in the patient group presenting with lateral cervical lymph node metastasis. On the whole, the present study demonstrated that paratracheal lymph node metastasis and tumor size were independent risk factors for lateral cervical lymph node metastasis.

Should multifocality be an indication for prophylactic central neck dissection in papillary thyroid cancer?

Although multifocality is common in patients with papillary thyroid cancer, its effects on lymphatic metastasis and the necessity of central dissection in the presence of multifocality are still controversial. In our clinic, 258 patients who underwent thyroidectomy between 2015 and 2020 and were found to have papillary thyroid cancer in postoperative pathology reports were analyzed. The tumor characteristics contributing to central lymph node metastasis positivity were evaluated. Lymph node metastases were not significantly increased in the presence of multifocality. In cases with bilateral multifocal tumors, compared to cases with unilateral multifocal tumors, capsular invasion (p = 0.02), vascular invasion (p = 0.01) and cervical lymphatic metastasis (p = 0.004) were observed to increase. Bilateral multifocal tumors have more aggressive clinicopathological features than unilateral tumors. We found that the risk of central lymph node metastasis increased significantly in bilateral multifocal tumors in our study. Prophylactic central lymph node dissection may be considered in patients with no preoperative or intraoperative lymph node metastasis but thought to have a multifocal tumor.

Tumor-Infiltrating Immune Cell Landscapes in the Lymph Node Metastasis of Papillary Thyroid Cancer

Regional lymph node metastasis (LNM) increases the risk of distant metastasis in papillary thyroid cancer (PTC) patients. However, it remains unclear how tumor cells in PTC patients with LNM evade immune system surveillance and proceed to colonize distant organs. Here, we comprehensively characterize the tumor-infiltrating immune cell landscape in PTC with LNM. LNM-related genes include multiple important soluble mediators such as CXCL6, IL37, MMP10, and COL11A1, along with genes involved in areas such as extracellular matrix organization and TLR regulation by endogenous ligands. In PTC without LNM, the tumor infiltration of activated dendritic cells and M0 macrophages showed increases from normal cells, but with yet greater increases and correspondingly worse prognosis in PTC with LNM. Conversely, the tumor infiltration of activated NK cells and eosinophils was decreased in PTC without LNM, as compared to normal cells, and yet further decreased in PTC with LNM, with such decreases associated with poor prognosis. We further demonstrate that mutations of driver genes in tumor cells influence the infiltration of surrounding immune cells in the tumor microenvironment (TME). Particularly, patients carrying TG mutations tend to show increased filtration of M2 macrophages and activated NK cells in the TME, whereas patients carrying HRAS mutations tend to show reduced filtration of M0 macrophages and show enhanced filtration of activated dendritic cells in the TME. These findings increase our understanding of the mechanisms of regional lymph node metastasis in PTC and its associated tumor microenvironment, potentially facilitating the development of personalized treatment regimens to combat immunotherapy failure.

Delphian lymph node metastasis predicts occult contralateral carcinoma for unilateral papillary thyroid carcinoma patients with contralateral benign nodules

BACKGROUND

For unilateral PTC patients with benign nodules in the contralateral lobe evaluated preoperatively, the necessity of total thyroidectomy remains controversial. This study aimed to investigate the predictive factors for occult contralateral carcinoma and whether DLN metastasis could predict it.

METHODS

A total of 148 patients with unilateral PTC and contralateral benign nodules who were treated with a near-total thyroidectomy or TT at a single institution between August 2018 and April 2020 were enrolled. Clinicopathological features such as age, sex, TgAb or TPOAb level, primary tumor location, nodule number in contralateral lobe, carcinoma number in primary lobe, tumor size, capsular invasion, central lymph node metastasis, DLN metastasis were analyzed to investigate the rate and predictive factors of occult contralateral carcinoma.

RESULTS

44.6% patients were diagnosed with occult contralateral thyroid carcinoma. Univariate analysis showed that sex (P = 0.008), mulifocality of primary carcinoma (P < 0.001), tumor size (P = 0.033), capsular invasion (P = 0.042), CLN metastasis (P = 0.004), DLN metastasis (P = 0.001) were associated with occult contralateral carcinoma. Multivariate analysis showed that multifocality of primary carcinoma (p = 0.000, OR = 9.729), DLN metastasis (p = 0.042, OR = 4.701), capsular invasion (p = 0.022, OR = 2.909), and male patients (p = 0.006, OR = 3.926) were all independent predictive factors.

CONCLUSION

For unilateral PTC patients with benign nodules in the contralateral lobe evaluated preoperatively, multifocality of primary carcinoma, DLN metastasis, capsular invasion, and male patients are independent predictors of occult contralateral carcinoma. We suggest separate excision and frozen section of DLN intraoperatively, if DLNs were confirmed metastasized, a TT was highly recommended.

Dynamic Risk Stratification for Predicting Long-term Outcomes in Pediatric Differentiated Thyroid Cancers

BACKGROUND

The American Thyroid Association (ATA) guidelines recommend Dynamic Risk Stratification (DRS) for predicting long-term outcomes and personalizing management in adult differentiated thyroid cancers (DTCs). However, its applicability in pediatric DTCs needs to be validated. Here, we attempted a validation study concerning the use of DRS in pediatric DTCs.

METHODS

Data of children (age ≤18 years) with DTCs and follow-up of ≥5 years were extracted. All patients were classified according to DRS (excellent, biochemical-, or structural-incomplete responses). Univariate and multivariate analyses were done to identify factor(s) affecting disease-free survival (DFS).

RESULTS

We included 176 pediatric DTC patients (median age at diagnosis: 15 years). All patients underwent thyroidectomy and received radioiodine as part of initial management. On the basis of clinical, biochemical, and imaging findings acquired during the first two years of follow-up, the DRS system divided patients into three response categories: excellent response in 82/176 (46.6%), biochemical-incomplete in 56/176 (31.8%), and structural-incomplete response in 38/176 (21.6%) patients. The median follow-up was 10.6 years (interquartile range: 7.7-15.5). Ten-year overall survival and DFS rates were 100% and 88.7%, respectively. In univariate analysis, DFS was significantly affected by extra-thyroidal extension (p = 0.002), lymph node metastasis (p = 0.018), ATA initial risk stratification (p = 0.033), and DRS (p = 0.004). However, in multivariate analysis, DRS alone showed a significant association with DFS (p = 0.016).

CONCLUSIONS

Like adults, DRS correctly predicts long-term outcomes in pediatric DTC. In addition to ATA initial risk stratification, DRS could further refine risk in pediatric DTCs and help in planning more personalised treatment and follow-up strategies.

Paediatric differentiated thyroid carcinoma: a UK National Clinical Practice Consensus Guideline

This guideline is written as a reference document for clinicians presented with the challenge of managing paediatric patients with differentiated thyroid carcinoma up to the age of 19 years. Care of paediatric patients with differentiated thyroid carcinoma differs in key aspects from that of adults, and there have been several recent developments in the care pathways for this condition; this guideline has sought to identify and attend to these areas. It addresses the presentation, clinical assessment, diagnosis, management (both surgical and medical), genetic counselling, follow-up and prognosis of affected patients. The guideline development group formed of a multi-disciplinary panel of sub-speciality experts carried out a systematic primary literature review and Delphi Consensus exercise. The guideline was developed in accordance with The Appraisal of Guidelines Research and Evaluation Instrument II criteria, with input from stakeholders including charities and patient groups. Based on scientific evidence and expert opinion, 58 recommendations have been collected to produce a clear, pragmatic set of management guidelines. It is intended as an evidence base for future optimal management and to improve the quality of clinical care of paediatric patients with differentiated thyroid carcinoma.

An immediate postoperative response to therapy assessment can help avoid unnecessary RAI therapy

Background

Radioiodine (RAI) therapy plays a vital role in the postoperative treatment of differentiated thyroid cancer (DTC) patients underwent total thyroidectomy (TT). However, even in the presence of capsular invasion and lymph node metastasis prognosis can be excellent and a postoperative RAI treatment might not be necessary for all patients. Therefore, this study explored the criteria for avoiding unnecessary RAI therapy in these patients.

Method

We applied response to therapy assessment immediately after surgery and prospectively recruited 179 excellent or indeterminate response DTC patients with capsular invasion and/or LNM who underwent TT without RAI therapy. During the follow-up, thyroglobulin (Tg), thyroglobulin antibody (TgAb) levels, and cervical ultrasonography were collected and analyzed. Disease-free survival (DFS) was calculated using the Kaplan-Meier method. In addition, response to therapy assessments was performed on patients during each follow-up.

Results

The mean follow-up period was 29.85 ± 17.44 months, and the 3- and 5-year DFS for all the patients was 99.3% in each. At the last follow-up, 165 (92.2%) patients had excellent responses, while 12 (6.7%) had an indeterminate response, and one (0.6%) each had biochemical and incomplete responses. No significant difference was observed in response to therapy between the subgroups of LNM and tumor invasion (P>0.05). For patients with capsular invasion and a number of metastatic lymph nodes ≤5 and >5, the proportions of recorded excellent responses were 95.9%, 91.0%, and 85.7%, respectively. Better responses were observed in females (excellent response: 95.5%, P=0.023), patients with stimulated Tg (s-Tg) ≤1ng/ml (excellent response: 100%, P<0.001), s-Tg ≤ 2ng/ml (excellent response: 98.4%, P<0.001), and excellent response for the immediate postoperative assessment (excellent response: 98.5%, P=0.004).

Conclusions

The current study suggested that the response to therapy assessment immediately applied postoperatively could help avoid unnecessary RAI therapy among DTC patients with capsular invasion and/or LNM. Moreover, excellent response patients and patients with indeterminate response and s-Tg ≤ 2ng/ml could be managed without RAI therapy.

Robot-Assisted Total Thyroidectomy with or without Robot-Assisted Neck Dissection in Pediatric Patients with Differentiated Thyroid Cancer

Pediatric thyroid cancer more frequently develops cervical node metastasis than adult thyroid cancer, even in differentiated thyroid carcinoma (DTC). Thus, cervical neck dissection often needs to be performed simultaneously with thyroidectomy in pediatric patients. Herein, we describe our experience with robot-assisted total thyroidectomy with/without robot-assisted neck dissection in pediatric patients compared with the conventional operated group. A total of 30 pediatric patients who underwent thyroidectomy for DTC between July 2011 and December 2019 were retrospectively reviewed. Among them, 22 underwent robot-assisted operation, whereas 8 underwent conventional operation. There was no statistical difference in the mean operation times, blood loss, drainage amounts, and hospital stay length between the robot-assisted and conventional operation groups; however, the operation time was less in the retroauricular approach subgroup (robot-assisted operation group) with better satisfaction on cosmesis. No postoperative complications, such as seromas, hemorrhages, or hematomas were observed. Our experience suggested that robot-assisted thyroidectomy with or without neck dissection through the retroauricular approach is a feasible and safe alternative treatment, producing outstanding esthetic results compared to the conventional approach, especially in pediatric patients with DTC.

Risk Factors for TERT Promoter Mutations with Papillary Thyroid Carcinoma Patients: A Meta-Analysis and Systematic Review

Whether TERT promoter mutation is related to more aggressive clinicopathologic features and worse outcomes in papillary thyroid carcinoma patients (PTCs) is still variable and controversial. Our intention was to investigate the risk or prognostic factors that may additionally predict the TERT promoter mutation doable of these lesions and new prevention techniques in PTCs. A total of 2,539 PTC patients with 11.50% TERT mutation have been analyzed using Revman 5.3 software in this study. The PubMed and Embase databases were systematically searched for works published until November 9, 2021. The following variables had been associated with an extended chance of TERT promoter mutation in PTC patients: age < 45 years (MD = 10.93, 95%CI = 7.25-14.61); gender = male (pooled OR = 1.63, 95%CI = 1.17-2.28); tumor size > 1 cm (MD = 0.56, 95%CI = 0.34-0.77); lymph node metastasis (pooled OR = 1.29, 95%CI = 0.93-1.79); vascular invasion (pooled OR = 1.78, 95%CI = 0.83-3.84); extrathyroidal extension (pooled OR = 2.00, 95%CI = 1.32-3.02); distant metastasis (pooled OR = 1.46, 95%CI = 1.04-2.04); advanced TNM stage (pooled OR = 3.19, 95%CI = 2.28-4.45). In addition, multifocality (pooled OR = 0.67, 95%CI = 0.14-3.24) had no affiliation with TERT promoter mutation in PTC patients. Our finding showed that age < 45 years, male, tumor size > 1 cm, lymph node metastasis, vascular invasion, and superior/advanced TNM stage were dangerous elements for TERT promoter mutation of worse effect in PTCs while that multifocality was once negatively correlated. TERT promoter mutation is drastically associated with recurrence and PTC-related mortality.

Predictive Factors for Recurrence of Papillary Thyroid Carcinoma in Children and Adolescents

Background

The incidence of papillary thyroid carcinoma (PTC) in children and adolescents has increased, but the data on long-term outcomes are limited. There are few literatures on the clinicopathological characteristics and prognosis of PTC in children and adolescents in China. Therefore, it is necessary to identify clinicopathological features to precisely predict clinical prognosis and to help choose the optimal method and perform the best therapeutic regimen.

Methods

This study was a retrospective analysis of patients undergoing thyroidectomy at Tianjin Medical University Cancer Institute and Hospital. We analyzed the factors related to the clinicopathological features and prognosis of PTC in children and adolescents.

Results

A total of 95 juvenile PTC patients who underwent thyroidectomy were enrolled. Our research found that patients with younger age (<14 years) were predominantly multifocal and have positive preoperative thyroglobulin (Tg) and higher recurrence rate, and their number of lymph node metastases (LNMs) was more than that of the older group (14–18 years). Maximal tumor size >2 cm, T stage, and multifocality were the risk factors for LNM and the number of LNM (p < 0.05). Multivariate analysis displayed the number of central LNM as the independent risk factor for lateral LNM, and multifocality was the independent risk factor for the number of central and lateral LNM. Younger age at diagnosis, positive preoperative thyroid-stimulating hormone (TSH), maximal tumor size >2 cm, lateral LNM, number of LNM, N staging, and American Thyroid Association (ATA) pediatric risk were related to poor prognosis in PTC patients (p < 0.05). Cox regression analysis found that younger age at diagnosis and positive preoperative TSH were independent risk factors for recurrence of PTC in children and adolescents.

Conclusions

Our study showed that the clinicopathological characteristics of younger age compared with older age were as follows: highly aggressive, prone to metastases, and higher recurrence rate. In our opinion, patients with characteristics such as younger age at diagnosis, positive preoperative TSH, maximal tumor size >2 cm, lateral LNM, and number of LNM >5 may be considered for prophylactic or therapeutic dissection of additional metastatic LNs by high-volume surgeons to prevent and reduce the recurrence rate of patients during long-term follow-up.

Cutoff Age Between Pediatric and Adult Thyroid Differentiated Cancer: Is 18 Years Old Appropriate?

Background: The characteristics of pediatric differentiated thyroid cancer (DTC) are substantially different from those of adult DTC. This study investigated whether the cutoff age of 18 years, as recommended by the American Thyroid Association (ATA) management guidelines for pediatric DTC, is appropriate based on clinical characteristics and outcomes. Methods: The medical records of 288 patients aged <21 years with DTC, who underwent initial surgery between 1979 and 2014, were retrospectively reviewed. Disease-free survival (DFS) rates and distant metastasis-free survival (DMFS) rates were calculated using the Kaplan-Meier method. As per the International Incidence of Childhood Cancer Report and the ATA management guidelines, cutoff ages of 14 and 18 years were analyzed in this study. Results: The age distributions of the subjects were as follows: 53 patients were aged <15 years (18.4%), 118 patients were aged 15-18 years (41%), and 117 patients were aged 19-20 years (40.6%). The DMFS rates were significantly different between the two cutoff ages. The DMFS was also significantly different between patients aged >15 years and patients aged 15-18 years; however, no significant difference was observed between patients aged 15-18 and 19-20 years. Multivariate analyses showed that clinically apparent lymph node metastasis (cN1) and gross extrathyroidal extension were significant factors related to DFS and DMFS. Although age as a continuous variant was not a significant factor related to either DFS or DMFS, when the cutoff age was set as 14 years rather than 18 years, differences in patient characteristics related to DMFS and DFS stood out. Conclusions: This study found that age was not significantly related to clinical outcome. However, in the younger patient group, more patients had factors that related to DFS and DMFS. Due to the indolent biological behavior of DTC, age at presentation or thyroidectomy does not always represent the age at occurrence, but patients aged <15 years had distinct clinical manifestations. Age <15 years rather than <19 years may therefore be a more suitable cutoff age in pediatric DTC.

Retrospective analysis of clinical characteristics and risk factors of differentiated thyroid cancer in children

BACKGROUND

The incidence rate of children with thyroid cancer has an increasing trend. This study aimed to investigate the clinical characteristics and therapeutic approaches of differentiated thyroid cancer (DTC) in Chinese children.

MATERIALS AND METHODS

From January 1998 to March 2022, 52 cases undergoing surgical resection in Xinhua Hospital affiliated to Shanghai Jiao Tong University were divided by age (≤ 7 years old: n = 14 and 8-13 years old, n = 38). Treatment methods and clinical features were analyzed to evaluate prognostic factors for oncological outcomes.

RESULTS

Among the 52 cases, the proportion of local invasion in the pre-school group was found to be higher than that in the school-age group (p = 0.01). T stage was significantly different between the two groups (p ≤ 0.05); the proportion of T_1-2 was higher in the school-age group (32 cases, 84.2%), while the proportion of T₄ was higher in the pre-school group (6 cases, 42.8%) relatively. The postoperative complication rate was dramatically higher in pre-school children (p ≤ 0.05). Additionally, the total thyroidectomy rate in the non-recurrent group was slightly higher than that in the recurrent group (p ≤ 0.05). Over half of the recurrent cases had low T stage and low ATA (American Thyroid Association) risk levels at initial diagnosis (78.3 and 51.4%).

CONCLUSION

The local invasion, tumor stage, and recurrent laryngeal nerve (RLN) injury rates of the pre-school group were higher than that of the school-age group, where young age served as a potential hazard in DTC children. Hence, surgeons should emphasize high-risk features and optimize individualized surgical procedures for DTC children.

Application of Carbon Nanoparticle Tracers in the Lateral Neck Lymph Nodes of CN1bx Patients with Papillary Thyroid Carcinoma

This study aimed to investigate the applicability of carbon nanoparticle tracers in the lateral neck lymph nodes of CN1bx patients with papillary thyroid carcinoma surgery. 73 patients with papillary thyroid carcinoma at our hospital between January 2019 to December 2019 were suspected metastasis in the lateral neck lymph node before surgical treatment. During the operation, carbon nanoparticle tracers were used as black staining tracers for the lateral neck lymph nodes to detect metastasis in each Compartment of the neck. The lateral Compartment is defined as level ll-V The black-stained lymph nodes, dyed by Carbon nanoparticle tracers, and non-dyed lymph nodes were compared. Post-surgery paraffin pathology was adopted as the gold standard to calculate the predictive performance of the carbon nanoparticle tracers in detecting lymph node biopsy metastasis. 59 of the patients (80.8%) had lateral neck metastasis. The black-stained lymph nodes, dyed by Carbon nanoparticle tracers, in Compartment IV exhibited the highest proportions in the case number submitted for detection and in lymph nodes metastasis, followed by Compartment III. The metastasis rate of the dyed lymph nodes in areas III and IV was significantly higher than that of non-dyed lymph nodes (P < 0.05). The sensitivity and accuracy of the dyed lymph node biopsy in Compartments III-IV were 90% and 93.2%, respectively. This predictive performance was similar to that Compartments ll-V combined. In conclusion, when carbon nanoparticle tracers are used for lymph node biopsy, high sensitivity and accuracy are obtained in lateral neck compartments III-IV, making these compartments ideal for lymph node biopsy.

Prognostic value of lymph node ratio in children and adolescents with papillary thyroid cancer

OBJECTIVE

Neck lymph node (LN) metastasis is a common feature of paediatric papillary thyroid cancer, and LN ratio (LNR) is defined as the ratio of the number of positive LNs excised to the total number of removed. Unlike in adults, few data are available regarding the clinical implication of LNR in the paediatric population. Our purpose was to investigate the association of LNR with clinical outcomes in paediatric papillary thyroid cancer.

DESIGN & METHODS

The study retrospectively reviewed 136 consecutive children and adolescents with papillary thyroid cancer and LN involvement but no initial distant metastasis. Initial treatment, included in all patients a total thyroidectomy with central and/or lateral neck dissection followed by radioactive iodine ablation. Within the neck dissections, total number of LNs removed, total positive LNs and LN ratios were determined. The effect of clinicopathologic characteristics and intraoperative findings on persistent and recurrent diseases were analysed by univariate and multivariate analyses.

RESULTS

Median number of positive LNs was 9, and median LNR was 0.4. During a median follow-up of 49 months (range, 12.0-139 months), persistent disease occurred in 43 (31.6%) patients. The multivariable analysis showed that age and LNR were the independent factors predictive of persistent disease. Patients with a LNR >0.34 exhibited a threefold higher risk of persistent disease after initial therapy than the counterparts (P = .02).

CONCLUSION

Our findings suggest that LNR was an independent determinant predictive of persistent disease after initial therapy in children and adolescents with papillary thyroid cancer.

Loss of ID3 drives papillary thyroid cancer metastasis by targeting E47-mediated epithelial to mesenchymal transition

Papillary thyroid cancer (PTC) is the main histological type of thyroid cancer and accounts for almost all increased cases worldwide. Patients with PTC exhibit a favorable prognosis, but the fact that PTC is often accompanied by a high prevalence of lymph node metastasis (LNM) means that the overall recurrence-free survival rate in PTC patients is relatively low. Herein, we identified that ID3 expression is subdued in PTC tissues and closely associated with LNM and a poor disease-free survival outcome in PTC patients. The main contributor to this gene repression is the hypermethylation of the CpG island at the promoter of ID3. Besides, we uncovered that a loss of ID3 promotes invasion and migration of PTC cells, while an ectopic overexpression of ID3 inhibits invasion and migration. Mechanistically, ID3 exhibits tumor suppressor functions in PTC cells by interacting with E47 to form heterodimers that prevent E47 binding to CDH1 promoter and maintaining CDH1 transcription and epithelial phenotype in PTC cells. Taken together, our study demonstrates that ID3 plays a tumor suppressor role in PTC and impedes metastasis by inhibiting E47-mediated epithelial to mesenchymal transition.

Clinical applications of single-photon emission computed tomography/computed tomography in post-ablation 131iodine scintigraphy in children and young adults with differentiated thyroid carcinoma

BACKGROUND

The utility of integrated single-photon emission computed tomography/computed tomography (SPECT/CT) in children and young adults with differentiated thyroid carcinoma is incompletely studied.

OBJECTIVE

To determine the value of adding SPECT/CT to conventional whole-body scintigraphy in post-ablation iodine-131 (¹³¹I) scintigraphy for children and young adults with differentiated thyroid carcinoma.

MATERIALS AND METHODS

Planar scintigraphy and SPECT/CT were performed on 42 post-surgical children and young adults (32 female, 10 male; mean age 14.3±4.9 years, range 7-20 years) with differentiated thyroid carcinoma (39 papillary, 2 follicular, 1 mixed) 5 days after the therapeutic administration of 1.9-7.4 GBq of ¹³¹I. Planar and SPECT/CT images were interpreted independently, and sites of uptake were categorized as positive or equivocal with respect to thyroid bed, lymph node and distant metastasis uptake. An experienced thyroid endocrinologist used a combination of surgical histopathology and scintigraphic findings to determine whether the addition of SPECT/CT would change patient management.

RESULTS

Planar scintigraphy evidenced 88 radioiodine-avid foci and SPECT/CT confirmed all foci. No additional foci were disclosed by SPECT/CT. SPECT/CT correctly classified 16/88 (18%) foci that were unclear or wrongly classified at planar scintigraphy. Globally, SPECT/CT showed an incremental value over planar scintigraphy in 9 (21.4%) patients and changed therapeutic management in 3 (7.1%; 95% confidence interval, 2-20%) patients.

CONCLUSION

SPECT/CT improved localization and characterization of focal ¹³¹I uptake on post-ablation whole-body scintigraphy in children and young adults with differentiated thyroid carcinoma. Further prospective evaluation in a larger series is justified to prove the effect of post-ablation SPECT/CT-based management decisions.

Trends in Pediatric Thyroid Cancer Incidence, Treatment, and Clinical Course in Korea During 2004-2016: A Nationwide Population-Based Study

Background: The incidence of thyroid cancer has increased worldwide. We investigated nationwide trends in the incidence and treatment course of pediatric thyroid cancer in South Korea. Methods: Using the National Health Information Database, we analyzed 1580 patients (324 males) <20 years of age diagnosed with thyroid cancer during 2004-2016 in South Korea. The annual percentage change (APC) in the age-standardized incidence rate (ASR) was calculated by joinpoint regression analysis. The initial treatment modality was categorized as either surgery only or surgery with radioactive-iodine treatment (surgery+RAIT), and we defined new treatment events as reoperations or additional RAITs among 1464 patients followed up for ≥12 months. Results: During 2004-2016, the mean ASR per 100,000 person-years increased from 0.6 [confidence interval; CI 0.5-0.8] to 0.9 [CI 0.8-1.1], with a mean APC of 4.0% [CI 1.8-6.2]. The ASRs (APCs) among 0-9-, 10-14-, 15-17-, and 18-19-year olds were 0.07 (9.9% [CI 0.08-20.7]), 0.6 (4.6% [CI 0.2-9.2]), 2.2 (3.9 [CI 1.7-6.0]), and 4.2 (3.5% [CI 0.9-6.2]), respectively. The lobectomy and lymph-node-dissection rates increased (from 18.5% to 33.6%, p = 0.0014; and from 29.6% to 84.5%, p < 0.001; respectively), but the RAIT rate decreased (67.9-39.7%, p < 0.001) during the study period. During a median 6.3-year follow-up, two patients died. New treatment events occurred in 56 (10.7%) of patients in the initial surgery-only group (n = 523). In the initial surgery+RAIT group (n = 941), 316 patients received two or more RAITs within 2 years, and 80 (12.8%) of the remaining 625 patients underwent new treatment events. In the surgery+RAIT subgroup, the event-free survival rate was lower in 0-14-year olds than in 18-19-year olds (hazard ratio 2.5 [CI 1.4-4.4]). Conclusions: The pediatric thyroid cancer incidence increased from 2004 to 2012 in South Korea. The lobectomy and lymph-node-dissection rates increased, but the RAIT rate decreased. The higher risk for new treatment events in patients younger than 15 years requiring initial RAIT may be linked to advanced stage at diagnosis, and it needs to be further evaluated.

High Incidence of Distant Metastasis Is Associated With Histopathological Subtype of Pediatric Papillary Thyroid Cancer - a Retrospective Analysis Based on SEER

OBJECTIVE

Children with papillary thyroid cancer (PTC) have a higher invasive rate and distant metastasis rate, but the mortality rate is lower with unknown reasons. The majority of PTC cases comprise classical papillary thyroid carcinoma (CPTC) and follicular variant papillary thyroid carcinoma (FVPTC). This study aimed to determine the relationship between histopathological subtype and rate of distant metastasis and investigate factors influencing distant metastasis in pediatric PTC.

METHODS

A total of 102,981 PTC patients were recruited from SEER registry, 2004-2015. Proportion of distant metastasis between children (≤18 years) and adults with different histopathological subtypes was compared by propensity score matching. The cut-off age for distant metastasis in children was calculated by receiver operating characteristic (ROC) curve, and the risk factors for distant metastasis in pediatric patients were analyzed by logistic regression models.

RESULTS

Among the 1,484 children and 101,497 adults included in the study, the incidence of CPTC patients with distant metastasis in children was higher than that in adults (p<0.001). The ROC curve was calculated, which yielded a cut-off age for distant metastasis in CPTC children as 16 years old. In CPTC, the proportion of young children (2-16 years) with distant metastasis was higher than that of adolescents (17-18 years) and adults (>18 years) (both p<0.001). While there was no such trend in FVPTC. In young children (2-16 years), the incidence of CPTC with distant metastasis was higher than FVPTC (p=0.006). There was no difference between the proportion of CPTC and FVPTC with distant metastasis in adolescents (17-18 years) and adults. Logistic regression models revealed that extrathyroidal extension, lymph node metastasis and CPTC histopathological subtype were risk factors for distant metastasis in young children aged 2 -16 years.

CONCLUSIONS

In CPTC, the incidence of distant metastasis in young children (2-16 years) was significantly higher than that in adolescents (17-18 years) and adults (>18 years). In patients with distant metastasis aged 2-16 years, the proportion of CPTC was higer than that of FVPTC. Extrathyroidal extension, lymph node metastasis, and CPTC histopathological subtype were risk factors for distant metastasis in young children aged 2-16 years.

Risk Factors for Central and Lateral Lymph Node Metastases in Patients With Papillary Thyroid Micro-Carcinoma: Retrospective Analysis on 484 Cases

BACKGROUND

Papillary thyroid micro-carcinoma (PTMC) is defined as a tumor with a larger diameter ≤1 cm which has an indolent course and satisfying prognosis. However, the incidence of lymph node metastasis of PTMC cannot be ignored. The aim of this study was to assess the incidence of lymph node metastasis in PTMC patients, as well as to evaluate the risk factors for both central lymph node metastases (CLNM) and lateral lymph node metastases (LLNM).

METHODS

Patients who underwent thyroidectomy from January 2017 to October 2020, and pathologically diagnosed with PTMC were enrolled in our study and their medical records were collected and analyzed.

RESULTS

A total of 484 PTMC patients were included. The incidence of central and lateral lymph node metastasis was 49.6% and 9.1%, respectively. Multivariate analysis demonstrated as independent risk factors for CLNM male sex, age <40 years, largest tumor size ≥5 mm and bilaterality. Extrathyroidal extension, presence of CLNM, number of CLNM ≥5 were strong indicators for LLNM.

CONCLUSION

The incidence of lymph node metastases in PTMC is non-negligible. The identification of potential risk factors for CLNM and LLNM would help tailor individual surgical interventions for patients with PTMC.

Long-term follow-up of differentiated thyroid carcinoma in children and adolescents

Objectives The aims were to analyze the clinical features, response to treatment, prognostic factors and long-term follow-up of children and adolescents with differentiated thyroid carcinoma (DTC). Methods Eighty patients with DTC were studied retrospectively. All underwent total or near-total thyroidectomy, and in 75 cases, ablative iodine therapy was recommended. Patients were assessed periodically by tests for serum thyroglobulin levels and whole-body iodine scans. Age, gender, initial clinical presentation, histology, tumor stage, postoperative complications, radioiodine treatment protocol, treatment response, thyroglobulin (Tg), recurrence and long-term disease progression were evaluated. Results Seventy patients completed >2 years of follow-up (23 males, 47 females; median age: 14 years; range: 3-18 years). Sixty-two patients showed papillary DTC and eight, follicular DTC. Sixty-five percent presented nodal metastasis and 16%, pulmonary metastasis at diagnosis. Six months after first radioiodine treatment, 36.2% of patients were free of disease. Seven recurrences were documented. At the end of follow-up, overall survival was 100%, and 87.2% of patients were in complete remission. Nine patients had persistent disease. We found a significant association between stage 4 and persistent disease. Hundred percent of patients with negative Tg values at 6 months posttreatment were documented free of disease at the end of the follow-up. The analysis of disease-free survival based on radioiodine treatment protocols used showed no statistically significant differences. Conclusions DTC in children and adolescents is frequently associated with presence of advanced disease at diagnosis. Despite this, complete remission was documented after treatment in most cases, with a good prognosis in the long-term follow-up. Negative posttreatment thyroglobulin and stage 4 at diagnosis were significant prognostic variables.

Distant Metastasis in Pediatric and Adolescent Differentiated Thyroid Cancer: Clinical Outcomes and Risk Factor Analyses

CONTEXT

The specific characteristics of pediatric and adolescent differentiated thyroid cancer (DTC) is the more frequent occurrence of distant metastasis (DM) compared with adult DTC.

OBJECTIVE

To investigate the clinical outcomes of DM in this population and analyze risk factors related to DM.

DESIGN, SETTING, AND PARTICIPANTS

Medical records of 171 patients with DTC < 19 years old, who underwent initial surgery between 1979 and 2014 were retrospectively reviewed.

MAIN OUTCOME MEASURE

Clinical responses to radioiodine (RAI) therapy evaluated by the American Thyroid Association (ATA) guidelines for adult DTC and Response Evaluation Criteria in Solid Tumors (RECIST) criteria. Risk factors related to distant-metastasis-free survival (DMFS).

RESULTS

DM was observed in 29 patients, and all were lung metastases. The pattern of lung metastasis was classified into 3 categories: macronodular, micronodular, and no apparent nodule (detected only by RAI scintigraphy). Patients with excellent responses according to the ATA guideline criteria or complete remission of the RECIST criteria were most frequently observed in those with no apparent nodule. Significant factors related to DMFS were sex, clinical lymph node metastasis (LNM), extrathyroidal extension, and number of LNM. Subjects were divided into 3 groups according to the number of risk factors: low risk (no risk factors); intermediate risk (1 risk factor); and high risk (≥2 risk factors). Twenty-year DMFS rates in the low-, intermediate-, and high-risk groups were 99.0%, 71.7%, and 28.6%, respectively.

CONCLUSION

To achieve the full efficacy of RAI therapy, early diagnosis of DM before apparent metastases appear is desirable. The selective approach would be preferable for pediatric and adolescent DTC.

Thyroid cancer and thyroid autoimmune disease: A review of molecular aspects and clinical outcomes

Thyroid cancer (TC) is the most prevalent malignant neoplasm that affects the endocrine system. Hashimoto's thyroiditis (HT), also known as chronic lymphocytic thyroiditis, is the most common autoimmune thyroid disease (AITD) that, together with Graves' disease (GD), represent the main autoimmune diseases that affect the thyroid gland. Some studies suggest a greater risk of AITD and the development of TC, while others, investigate its relationship with TC progression and patient prognosis. In this review, we have analyzed published data on the molecular aspects related to the association between AITD and TC, addressing their influence on TC progression, diagnosis, and prognosis of the patients. MEDLINE database (PubMed) platform was used as a search engine and the original articles related to the topic were selected using the keywords combination "thyroid cancer and Hashimoto thyroiditis" or "thyroid carcinoma and thyroid autoimmune disease". After the selection, we categorized the main findings of the papers into four topics: antitumor immunity, tumor progression, diagnosis, and prognosis. Although most of the studies have pointed out the presence of AITD as a factor that increases the risk of TC, few molecular mechanisms to support this conclusion have been described. Additionally, little information is available to explain, pathophysiologically, the effects of autoimmunity in TC diagnosis, progression, and prognosis.

Predictors of recurrence after total thyroidectomy plus neck dissection and radioactive iodine ablation for high-risk papillary thyroid carcinoma

BACKGROUND

American Thyroid Association (ATA) proposed management guidelines for differentiated thyroid cancer, including a three-tiered risk stratification system for structural recurrence. This study aimed to compare the various 2015 ATA criteria for the strength of association with the recurrence of high-risk papillary thyroid carcinoma (PTC).

STUDY DESIGN

This study included 545 consecutive patients who underwent total thyroidectomy plus neck dissection and radioactive iodine ablation (RAI) for previously untreated high-risk PTC. The association of recurrence-free survival (RFS) with clinicopathological factors was evaluated by univariate and multivariate Cox proportional hazard regression analyses.

RESULTS

During a follow-up median period of 89 months, 90 (16.5%) patients had any-site recurrence. Of the high-risk factors, high stimulated thyroglobulin (sTg) level and >3-cm sized lymph nodes (LNs) were significantly associated with recurrence (all P < .005). Sex, tumor size, lymphovascular invasion, multifocality, number of positive LNs, extranodal extension, T and N classifications, and overall tumor-node-metastasis stage were also significantly associated with recurrence (all P < .05). In multivariate analyses, high sTg level [adjusted hazard ratio (HR) = 7.18] and N1b (adjusted HR = 3.27) were independent factors predictive of recurrence (all P ≤ .001).

CONCLUSIONS

Postoperative high serum sTg level might be the most important predictor of PTC recurrence after total thyroidectomy plus neck dissection and RAI.

Risk Factors for Lymph Node Metastasis in Papillary Thyroid Carcinoma: A Systematic Review and Meta-Analysis

Purpose: To explore the risk factors that may predict the lymph node metastasis potential of these lesions and new prevention strategies in papillary thyroid carcinoma patients. Materials and Methods: In total, 9,369 papillary thyroid carcinoma patients with 37.17% lymph node metastasis were analyzed (Revman 5.3 software) in this study. The PubMed and Embase databases were used for searching works systematically that were published through to January 22, 2020. Results: Several factors were related to the increased risk of lymph node metastasis in patients with papillary thyroid carcinoma: age <45 years (pooled OR = 1.52, 95% CI = 1.14-2.01, p <0.00001); gender = male (pooled OR = 1.68, 95% CI = 1.51-1.87, p <0.00001); multifocality (pooled OR = 2.05, 95% CI = 1.45-2.89, p <0.0001); tumor size ≥1.0 cm (pooled OR = 3.53, 95% CI = 2.62-4.76, p <0.00001); tumor location at the upper pole 1/3 (pooled OR =1.46, 95% CI = 1.04-2.04, p = 0.03); capsular invasion + (pooled OR = 3.48, 95% CI = 1.69-7.54, p = 0.002); and extrathyroidal extension + (pooled OR = 2.03, 95% CI= 1.78-2.31, p <0.00001). However, tumor bilaterality (pooled OR = 0.85, 95% CI = 0.54-1.34, p = 0.49) and Hashimoto's thyroditis (pooled OR = 1.08, 95% CI = 0.79-1.49, p = 0.62) showed no correlation with lymph node metastasis in papillary thyroid carcinoma patients. Conclusion: The systematic review and meta-analysis defined several significant risk factors of lymph node metastasis in papillary thyroid cancer patients: age (<45 years), gender (male), multifocality, tumor size (>1 cm), tumor location (1/3 upper), capsular invasion, and extra thyroidal extension. Bilateral tumors and Hashimoto's thyroiditis were unrelated to lymph node metastasis in patients with papillary thyroid cancer.

Risk Stratification of Pediatric Patients with Differentiated Thyroid Cancer: Is Total Thyroidectomy Necessary for Patients at Any Risk?

Background: In the recent American Thyroid Association (ATA) guidelines for adult differentiated thyroid carcinoma (DTC) patients, risk stratification is clearly defined and lobectomy is acceptable for low-risk DTC. However, risk stratification for children with DTC in the ATA pediatric guidelines is rather unclear, and total thyroidectomy is recommended for all patients with any risk. The aim of this study was to attempt risk stratification based on our experience and to consider the appropriate extent of thyroidectomy, especially for low-risk DTC in the pediatric population. Patients and Methods: The subjects were 153 patients with DTC ≤18 years old, including 58 patients ≤15 years old and 136 female patients, who underwent initial curative surgery in our hospital between 1979 and 2014. Underlying pathology was papillary thyroid carcinoma in 130 patients and follicular thyroid carcinoma in 23. Risk factors related to disease-free survival (DFS) were analyzed and risk stratification was performed. Results: No patient died of the disease and 34 patients (22.2%) developed recurrences. At initial surgery, 30 patients (19.6%) had lymph node metastases diagnosed before initial surgery (cN1) and 9 (5.9%) had gross extrathyroidal extension (ETE). Significant factors related to DFS on multivariate analysis were cN1, ETE, and number of metastatic lymph nodes (NMLNs) ≥10, including microscopic MLNs. According to these factors, subjects were divided into three categories: low risk (no risk factors, n = 89); intermediate risk (1 risk factor, n = 37); and high risk (≥2 risk factors, n = 27). Ten-year DFS rates in the low-, intermediate-, and high-risk groups were 96%, 83%, and 48%, respectively. Only 12% of low-risk patients underwent total thyroidectomy. Because NMLNs become obvious only after surgery, another analysis after excluding "NMLNs" as a factor showed that cN and ETE were significant factors related to poor DFS. According to these two factors, risk stratification was attempted in the same manner. Ten-year DFS rates in the low- (no risk factor, n = 117), intermediate- (one risk factor, n = 29), and high-risk (two risk factors, n = 7) groups were 92%, 59%, and 43%, respectively. Only 12% of low-risk patients underwent total thyroidectomy. Conclusions: For low-risk pediatric patients, lobectomy may be sufficient as the initial surgical procedure.

Prognostic value of tumor size and minimal extrathyroidal extension in papillary thyroid carcinoma

BACKGROUND

Tumour size and extrathyroidal extension (ETE) may impact papillary thyroid carcinoma (PTC) outcomes. We therefore examined the prognostic value of tumour size and ETE for predicting posttreatment recurrence in PTC patients.

METHODS

A total of 2,902 patients who underwent thyroidectomy for previously untreated T1-T3 PTC (7th edition American Joint Committee on Cancer) at our tertiary referral center were included. Univariate and multivariate Cox proportional hazard regression analyses were used to determine significant factors predictive of posttreatment recurrence-free survival (RFS).

RESULTS

In univariate analysis, tumour factors (including tumour size, multifocality, ETE, and lymphovascular invasion), nodal factors (including positive lymph node number, lymph node ratio, and extranodal extension), and MACIS (metastases, age, completeness of resection, invasion, and size) scores were significantly associated with RFS outcomes (P < 0.001). In multivariate analysis, tumour size >4 cm (P < 0.001) and multifocality (P = 0.038) were the independent factors of RFS. Nodal factors and MACIS scores were also independent factors of RFS.

CONCLUSION

Tumour size impacts RFS after thyroidectomy in T1-T3 PTC patients.

Downregulating integrin subunit alpha 7 (ITGA7) promotes proliferation, invasion, and migration of papillary thyroid carcinoma cells through regulating epithelial-to-mesenchymal transition

Thyroid cancer is one of the common malignancies of the endocrine system and the number of thyroid cancer cases is increasing constantly. Significant work has focused on the molecular mechanisms of thyroid cancer, but many mechanisms remain undiscovered. In this study, we employed a comprehensive analysis of whole-transcriptome resequencing derived from paired papillary thyroid cancer (PTC) and normal thyroid tissues. We performed a massive parallel whole-transcriptome resequencing of matched PTC and normal thyroid tissues in 19 patients and found that integrin subunit alpha 7 (ITGA7) was downregulated in thyroid tumor tissues, but the function of ITGA7 in this cancer is still unclear. We also discovered that ITGA7 gene in thyroid cancer tissues was downregulated compared to paired adjacent non-tumor tissues by real-time quantitative polymerase chain reaction. After transfection with small interfering RNA to knock down ITGA7, the abilities of colony formation, proliferation, migration, and invasion were enhanced in PTC cell lines (TPC1 and KTC-1). Meanwhile, ITGA7 knockdown decreased apoptotic cell death in thyroid cells but promoted the expressions of N-cadherin and vimentin and decreased E-cadherin expression by epithelial-to-mesenchymal transition, which may induce invasion and migration. In conclusion, these results indicated that ITGA7 is involved in the progress of PTC and might act as a tumor suppressor gene.

Metabolomics as a potential method for predicting thyroid malignancy in children and adolescents

PURPOSE

To identify potential metabolic biomarkers for distinguishing malignant and benign thyroid nodules in children and adolescents using a metabolomics approach.

METHODS

A total of 96 consecutive patients (median age 14.29 ± 2.31 years, range 9-18 years) who underwent thyroidectomy and 40 healthy controls were enrolled. Patients were assigned to the papillary thyroid carcinoma and benign thyroid adenoma groups according to postoperative pathologic biopsy. Plasma samples were preoperatively collected, and multivariate analysis was performed to identify differential metabolites.

RESULTS

Papillary thyroid carcinoma could be distinguished not only from healthy serum but also from benign thyroid adenoma according to the metabolic profiles. A total of 17 metabolites were identified. Compared with those from benign thyroid adenoma patients and healthy controls, the metabolites from papillary thyroid carcinoma patients, including leucine, lactate, alanine, glycine, acetate, lysine and choline, were increased, while glucose was decreased.

CONCLUSION

The metabolomics method based on proton nuclear magnetic resonance has great potential for identifying papillary thyroid carcinoma in children and adolescents. Lactate and glycine may be used as potential serum markers for the diagnosis of papillary thyroid carcinoma.

Risk factors for posttreatment recurrence in patients with intermediate-risk papillary thyroid carcinoma

BACKGROUND

Papillary thyroid carcinoma (PTC) is generally associated with favorable outcomes; however, intermediate-risk requires further evaluation. We therefore examined risk factors for posttreatment recurrence in patients with intermediate-risk PTC.

METHODS

This study involved 1782 patients who underwent thyroidectomy for intermediate-risk PTC. Univariate and multivariate Cox proportional hazard regression analyses were used to identify the significant factors predictive of posttreatment recurrence-free survival (RFS).

RESULTS

Of intermediate-risk factors, univariate analyses showed that clinical and pathological cervical lymph node (LN) positivity (cN1 and pN1), aggressive histology, and multifocality with microscopic extrathyroidal extension were significantly associated with RFS outcomes (all P < 0.05). In multivariate analyses, cN1, >5 pN1, and posttreatment radioactive iodine (RAI)-avid metastatic foci of intermediate risk remained the independent factors predictive of RFS (all P < 0.05). The combination of any three or more of these intermediate-risk factors appeared to increase the posttreatment recurrence rate.

CONCLUSION

Clinical nodal positivity, the number of positive LNs, and the presence of RAI-avid metastatic foci in the ATA intermediate-risk category might independently decrease RFS in patients with intermediate-risk PTC.

CYTOLOGICAL CHARACTERISTICS OF POSTOPERATIVE METASTASES OF PAPILLARY THYROID CANCER DURING THE DEVELOPMENT OF SECONDARY RADIOIODINE REFRACTORINESS

Radioiodine refractoriness is the main problem in the diagnosis and treatment of papillary thyroid carcinoma. The aim of the study was to investigate the cytological and immunocytochemical changes of thyrocytes in fine-needle aspiration smears of thyroid papillary cancer metastases in the course of the development of secondary radioiodine resistance. A total of 70 postoperative metastases of thyroid papillary cancer (secondary radioiodine refractory metastases, previously responsive to radioiodine, that eventually loses the ability to radioiodine accumulation, radioiodine-avid metastases, primary radioiodine-refractory metastases), immunohistochemical staining of thyroid peroxidase, thyroglobulin, cytokeratin 17 and cytological analysis were performed. Revealing the presence of specific cellular phenotypes and structures in punctuates, a low percentage of thyroid peroxidase and thyroglobulin-positive thyrocytes allows the development of the method of cytological prediction of the radioiodine therapy effectiveness.

LINC00511 influences cellular proliferation through cyclin-dependent kinases in papillary thyroid carcinoma

Background: Proverbially, the incidence rate of papillary thyroid carcinoma (PTC) has increased year by year. Many long noncoding RNAs (lncRNAs) have been discovered having a relationship with tumor genesis tightly recently. Thanks to the previous researches, we found long intergenic noncoding RNA 00511 (LINC00511) is overexpressed and acts as an oncogene in non-small-cell lung cancer and breast cancer. However, the biological role and function of LINC00511 are still unclear in PTC. Methods: We got the expression of LINC00511 in PTC tissues and matched adjacent tissues, as well the cell lines (B-CPAP, KTC-1, and KTC-1) by way of quantitative real-time polymerase chain reaction (qRT-PCR). In vitro, we knocked down the LINC00511 with small interfering RNA in PTC cell lines and demonstrated the function of LINC00511 by Cell Counting Kit-8, cell colony formation, Transwell migration, Transwell invasion, apoptosis assays, and cell cycle assays. Then, we discovered several downstream proteins of LINC00511 using Western blotting. Results: We proved that LINC00511's expression in PTC tissues and cell lines is higher than the control. LINC00511 promoted cellular proliferation, migration, invasion, G1/S transition and reduced apoptosis in vitro experiment. Knocked-down of LINC00511 resulted in the reduction of histone methyltransferase enhancer of zeste homolog 2 (EZH2), cyclin-dependent kinase 2 (CDK2) and cyclin-dependent kinase 4 (CDK4). Conclusions: Our results certified the role and function of LINC00511 in PTC, and it could become a novel tumor therapeutic target.

Differentiated thyroid carcinoma in children: Clinical characteristics and long-term follow-up

Differentiated thyroid cancer (DTC) is rare in children, but it still remains the most common endocrine malignancy in children. The aim of this study was to analyze treatment response to radioactive iodine (RAI) therapy, clinical outcomes, recurrences, survival analysis, and long-term follow-up. We retrospectively reviewed the medical records of 43 pediatric patients (≤17 years of age) with DTC diagnosis after thyroidectomy who were treated with RAI. The follow-up protocol consisted of detailed clinical examination, testing of thyroid function, determination of serum thyroglobulin (Tg), and anti-Tg antibodies, and neck ultrasonography application. Forty-three pediatric patients (34 females and 9 males) treated with RAI for DTC in our institute. The median follow-up period was 54 months. The histologic classification was papillary thyroid cancer in 41 patients and the remaining 2 patients had follicular thyroid cancer. After the long-term follow-up, complete remission, partial remission, and recurrent-persistent disease were observed in 37 patients, 3 patients, and 3 patients, respectively. Among the series, 1 death occurred due to multiple metastases. The mortality rate is 2.56%. Total thyroidectomy followed by RAI appears to be the most effective treatment for patients with pediatric DTC in terms of reducing the rate of relapse and improving surveillance for recurrent disease.

Predictive Factors of Recurrence in Patients with Differentiated Thyroid Carcinoma: A Retrospective Analysis on 579 Patients

Differentiated thyroid carcinoma (DTC) is usually associated with a favorable prognosis. Nevertheless, up to 30% of patients present a local or distant recurrence. The aim of this study was to assess the incidence of recurrence after surgery for DTC and to identify predictive factors of recurrence. We included in this retrospective study 579 consecutive patients who underwent thyroidectomy for DTC from 2011 to 2016 at our institution. We observed biochemical or structural recurrent disease in 36 (6.2%) patients; five-year disease-free survival was 94.1%. On univariate analysis, male sex, histotype, lymph node yield, lymph node metastasis, extrathyroidal invasion and multicentricity were associated with significantly higher risk of recurrence, while microcarcinoma was correlated with significantly lower risk of recurrence. On multivariate analysis, only lymph node metastases (OR 4.724, p = 0.012) and microcarcinoma (OR 0.328, p = 0.034) were detected as independent predictive factors of recurrence. Postoperative management should be individualized and commensurate with the risk of recurrence: Patients with high-risk carcinoma should undergo strict follow-up and aggressive treatment. Furthermore, assessment of the risk should be repeated over time, considering individual response to therapy.

Low expression of ryanodine receptor 2 is associated with poor prognosis in thyroid carcinoma

Genetic alterations are vital in the progression of thyroid carcinoma. Ryanodine receptor 2 (RyR2) is reported to serve an important role in several types of human carcinoma. However, the expression and effect of RyR2 in thyroid carcinoma remain unknown. Therefore, the present study analyzed the status of RyR2 in thyroid carcinoma using bioinformatics tools. The mRNA profiles of thyroid carcinoma were downloaded from The Cancer Genome Atlas. RyR2 was distinguished as a differentially expressed gene that has not been reported in thyroid carcinoma. Further analysis indicated that there was selective downregulation of RyR2 expression in thyroid carcinoma tissues compared with that in normal thyroid tissues. Survival analysis showed that RyR2 expression was associated with poorer disease-free survival (DFS) for all patients with thyroid carcinoma. Univariate analysis revealed that a low expression of RyR2 was significantly associated with lymphatic metastasis, extracapsular extension, and the Tumor-Node-Metastasis stage. Cox analysis demonstrated that RyR2 was an independent prognostic factor in thyroid carcinoma for DFS. The biological processes and signaling pathways of RyR2 were reviewed with Gene Set Enrichment Analysis. In conclusion, the present study has revealed that RyR2 is downregulated in thyroid carcinoma, and that low expression of RyR2 is associated with poor prognosis in patients with thyroid carcinoma. RyR2 may therefore serve as a promising tumor suppressor gene in thyroid carcinoma.

Up-Regulated AKR1C2 is correlated with favorable prognosis in thyroid carcinoma

Purpose: Aldo-keto reductase family 1, member C2 (AKR1C2) gene encodes for a member of the AKR superfamily and participates in the metabolism of various drugs. Moreover, tumor and normal tissues exhibit an evident difference in the expression level of this gene. Methods: We downloaded and analyzed AKR1C2 expression level and the data consisting of the clinicopathological features of 490 papillary thyroid carcinoma (PTC) tumor tissues and 59 normal thyroid tissues from The Cancer Genome Atlas (TCGA) cohort. Diverse statistical methods, such Chi-square test, univariate and multivariate Cox regression analyses, and Kaplan-Meier survival curves were used. We down-/up-regulated the expression of AKR1C2 and explored its specific role in thyroid cancer cell lines by utilizing the si-RNA and plasmid. Results: We divided all patients who were collected in TCGA data sets into under-expressed (n = 245) and over-expressed groups (n = 245). We subsequently analyzed the data and obtained the following findings: (a) AKR1C2 is down-regulated in papillary thyroid carcinoma (PTC) (p<0.001), (b) Kaplan-Meier result revealed that high expression level of AKR1C2 are correlated with favorable survival in PTC (p = 0.043), and (c) factors independently associated with recurrence-free survival are AKR1C2 expression (hazard ratio (HR 0.819) and American Joint Committee on Cancer (AJCC) stage (HR 1.534). We also analysed the relationship between AKR1C2 expression and clinicopathological features in the validated cohort. AKR12C under-expression correlated with lymph node metastasis (p = 0.009) and AJCC stage (p= 0.001) which might indicate AKR12C as a prognostic factor in PTC. The cell line experiment results showed that the knockdown and overexpression of AKR1C2 significantly enhance and weaken the abilities of migration and invasion in papillary thyroid carcinoma cell. Conclusion: Our results indicated that AKR1C2 exerts inhibitory effects on PTC oncogenesis and elevated AKR1C2 expression is associated with the favorable prognostic factors and recurrence free survival.

Clonal analysis of early-stage bilateral papillary thyroid cancer identifies field cancerization

INTRODUCTION

Bilaterality is a newly identified indicator for aggressive tumor behavior and poor outcome in papillary thyroid cancer. However, the clonal origin of these bilateral tumors remains unclear.

METHODS

Here we analyzed 28 pairs of early-stage papillary thyroid cancers (stage I-II without extra-thyroidal extension, lymph node metastasis or distant metastasis) that underwent surgery at First Affiliated Hospital of Zhejiang University School of Medicine (Hangzhou, China). Genomic DNA was extracted from paraffin-embedded tissues after microdissection and analyzed for BRAF mutation and X-chromosome inactivation.

RESULTS

A total of 16 patients (16/28, 57.1%) harbored different BRAF status in bilateral tumors. Fourteen patients were available for X-chromosome inactivation assay and 10 of them achieved informative results. Bilateral tumors from four cases had distinct patterns of X-chromosome inactivation. Combining the results of X-chromosome inactivation and BRAF analysis, we demonstrated that at least 64.3% (18/28) cases harbored discordant X-chromosome inactivation or BRAF status, indicating their independent clonal origin in bilateral tumors.

CONCLUSIONS

The present study confirms "field cancerization" in early-stage bilateral thyroid cancers, suggesting that these subtype papillary thyroid cancers should be treated as independent and localized tumors.

CHARACTERISTICS OF SUBCLONAL STRUCTURE IN THYROCYTE POPULATION IN RADIOIODINE-REFRACTORY METASTASES OF PAPILLARY THYROID CANCER

The aim of the study was cytological and immunocytochemical researches of thyrocyte populations in fine-needle aspiration smears of radioiodine-refractory metastases and their comparison with radioiodine-avid metastases and corresponding primary papillary carcinoma of the thyroid. Materials and Methods. The cytomorphological and immunocytochemical researches were conducted on the fine needle aspiration smears of 60 papillary thyroid carcinomas and 104 metastases, which were detected in the postoperative period. We applied the indirect immunoperoxidase technique using primary monoclonal mouse antibodies against leukocyte-common antigen, macrophage antigen, thyroglobulin, epithelial cell adhesion molecule, cytokeratines 7.8, polyclonal rabbit antibodies against calcitonin. Results. It was demonstrated, that radioiodine-avid metastases and corresponding primary papillary thyroid carcinoma smears had first type of cellular population with a relatively regular location of thyrocytes. Unlike them, radioiodine-refractory metastases smears had the second type of cellular population with irregularly location of thyrocytes among which showed up two cellular phenotypes. In our investigated smears some special cellular complexes were found – in 21 % of radioiodine-refractory metastases, 1 % in radioiodine-avid metastases and none of it in corresponding primary papillary thyroid. The cytological sign of cystic degeneration was found in 58 % of radioiodine-refractory metastases, but in radioiodine-avid metastases – was absent. Conclusion. The radioiodine-refractory metastases of papillary thyroid cancer demonstrated their distinction from radioiodine-uptake metastases with a presence of phenotypic heterogeneity. It is shown, that an appearance of certain cell subpopulations, special cellular complexes and cystic degeneration in fine-needle aspiration smears of radioiodine-refractory metastases, which in radioiodine-uptake metastases and corresponding primary papillary thyroid carcinomas were not found, can be used during the preoperative period to forecast the impossibility of radioiodine treatment.

Multifocality of papillary thyroid carcinoma as a risk factor for disease recurrence

OBJECTIVES

Tumor multifocality or bilaterality is associated with increased risk of papillary thyroid carcinoma (PTC) recurrence. However, its prognostic value in clinical outcomes remains controversial. This study aimed to evaluate the association of multifocality or bilaterality with recurrence and survival after total thyroidectomy.

METHODS

This was a retrospective study of 2390 consecutive patients with pathologically confirmed PTC who underwent total thyroidectomy. Multifocality and bilaterality were decided based on the final pathology results, that is, if there were two or more tumor foci and bilateral location, respectively. Primary outcomes were recurrence-free survival (RFS). Cox proportional hazards regression analyses were used to assess the associations of multifocality, bilaterality, and other clinicopathological factors with RFS.

RESULTS

Multifocal and bilateral PTC were found in 892 (37.3%) and 593 (24.8%) patients, respectively. Multivariate analyses showed that multifocality, lymphovascular invasion, N category, and number of positive lymph node (>5) were significant independent variables predictive of RFS (all P < 0.05). Multifocality was associated with adjusted hazard ratios for RFS of 1.93 (95% confidence interval = 1.33-2.80; P = 0.001). In a subset analysis, the prognostic value of multifocality was found to be significant in those patients with PTC > 1 cm, but not in papillary thyroid microcarcinoma.

CONCLUSIONS

Tumor multifocality is an independent risk factor of PTC recurrence after total thyroidectomy. This indicate a more progressive state of disease, being included in risk stratification.

DIFFERENTIATED THYROID CANCER IN PEDIATRIC POPULATION (≤18 YEARS): POSTOPERATIVE TREATMENT WITH RADIOACTIVE IODINE (I-131)

The aim is to present data on the treatment and follow-up in a cohort of patients with pediatric thyroid cancer who underwent total thyroidectomy and received postoperative radioactive iodine (I-131) therapy. The study was conducted in a tertiary high-volume thyroid center, in pediatric patients with differentiated thyroid cancer who were consecutively treated during the 1965-2015 period. A total of 45 patients aged ≤18 years having undergone total thyroidectomy with or without selective neck dissection were included in the study. Decision on postoperative I-131 ablation was based on tumor characteristics, postoperative thyroglobulin level, preablative whole body scintigraphy, and/or neck ultrasound. Median age at diagnosis was 15 years. The presence of cervical lymph node metastases was significantly associated with papillary thyroid cancer, larger tumor size, involvement of two thyroid lobes, and multifocal disease. The presence of distant metastases was significantly associated with larger tumor size. None of the patients died during follow-up period, and the 5-year and 10-year overall survival rates were 100%. The 5-year and 10-year progression-free survival (PFS) rates were 87% and 73%, respectively. Male gender (p=0.046), age ≤15 years (p=0.029) and tumor size >15 mm (p=0.042) were significantly associated with inferior PFS. A significant positive trend of increase in the number of newly diagnosed patients was observed over time (p=0.011). Clinical management of pediatric thyroid cancer is challenging, especially in the light of increasing incidence in this population. Male patients younger than 15 years and with tumors of more than 15 mm in size require additional caution due to lower PFS observed.

Recent Trends in the Clinicopathological Features of Thyroid Nodules in Pediatric Patients: A Single Tertiary Center Experience over 25 Years

BACKGROUND

The trends in pediatric patients having thyroid nodules have not been well evaluated. Here, we analyzed the clinicopathological features of the children who have presented with thyroid nodules at our center over several decades in order to determine a change of trend.

MATERIALS AND METHODS

We analyzed 215 pediatric patients who had undergone a thyroidectomy between 1990 and 2014 at our single tertiary center. The clinicopathological features were analyzed according to age, sex, and the year of diagnosis.

RESULTS

The most common reason for hospital admission was a palpable anterior neck mass (76.7%). The males in the patient cohort were younger than the females (13 vs. 15 years old, p < 0.05). The female patients increased from 50.0% to 83.0% with age (p < 0.05). The rate of malignancy did not increase with age (p < 0.05). However, the malignancy rate was higher in the more recently seen patients (23.8% during the early study period and 86.8% in the late study period; p < 0.05).

CONCLUSION

Following a thyroidectomy in children with thyroid nodules, there was no change in the rate of detection of thyroid cancer over time with age, although the detected frequency of malignancy has increased in more recent patients. Therefore, early thyroid nodule detection for malignant screening is likely to be required for pediatric patients in the near future.

CLDN10 is Associated with Papillary Thyroid Cancer Progression

The incidence of thyroid cancer is staying at a high level. Claudin family is a skelemin contacting with the intercellular junction and can keep a dynamic balance between cells. Recently, many types of research indicated that the expression level of claudins is closely related to various cancer types and they can be novel diagnostic markers. For instance, Claudin-10(CLDN10) is the high expression in primary hepatocellular carcinoma, papillary thyroid cancer (PTC) and so on. But the biological role and function of CLDN10 in PTC are unclear. In our study, we measured the expression of CLDN10 in human normal tissues and matched PTC tissues by quantitative real-time polymerase chain reaction (qRT-PCR) and this observation was consistent with that in the TCGA cohort. We discovered that high expression of CLDN10 was correlated with lymph node metastasis, age and Histological type in TCGA cohorts. Kaplan-Meier analysis showed that patients with higher CLDN10 expression had a worse overall survival. In vitro, CLDN10 could promote cellular proliferation, migration, and invasion in PTC cell lines. In a word, CLDN10 is a functionally gene facilitating tumorgenesis in PTC and acts as an oncogene in PTC.

Dynamic Risk Stratification in the Follow-Up of Children and Adolescents with Differentiated Thyroid Cancer

BACKGROUND

Risk stratification for persistent disease is an important step in pediatric differentiated thyroid cancer (DTC) management. The dynamic risk stratification (DRS) is a well validated system for adults, but not yet for children and adolescents. This study evaluated the DRS as well as other prognostic factors in pediatric DTC.

METHODS

Patients aged ≤18 years from four DTC tertiary teaching hospitals in Southern Brazil were included. Clinical characteristics were systematically retrieved, and all patients were classified according to the risk-stratification system of the 2015 American Thyroid Association pediatric DTC guidelines (ATA risk) and according to DRS (excellent, indeterminate, biochemical, or structural incomplete responses). Disease status was evaluated after initial therapy and at last follow-up visit.

RESULTS

Sixty-six patients aged 14.5 ± 3.0 years were studied of whom 54 (81.8%) were girls and 62 (93.9%) had papillary thyroid carcinomas. Tumor size was 2.3 cm (P25-75 1.6-3.5); 41 (63.1%) had cervical and 18 (27.7%) distant metastasis at diagnosis. All patients underwent total thyroidectomy, and 63 (95.5%) received radioiodine. Patients were classified according to DRS after initial therapy (n = 63) as follows: 21 (33%) excellent, 13 (21%) indeterminate, 6 (9%) biochemical, and 23 (37%) structural incomplete responses. Notably, after six years (P25-75 2.7-10.0), most patients remained in the same category. Interestingly, the cutoff analysis of stimulated postoperative thyroglobulin (sPOTg) through receiver operating characteristic curve showed that the value of 37.8 ng/mL showed 81% sensitivity and 100% specificity to predict an excellent response. Prognostic factors associated with persistent disease in the univariate analysis were TNM, ATA risk, DRS, and sPOTg.

CONCLUSION

DRS after initial therapy and sPOTg are strong predictors of disease outcome and might be helpful for defining follow-up strategies in pediatric DTC.

Usefulness of dynamic risk stratification in pediatric patients with differentiated thyroid carcinoma

Purpose

Recently, the American Thyroid Association (ATA) dynamic risk stratification (DRS) has been verified to be more valuable than the static anatomical staging system for predicting prognosis in patients with differentiated thyroid carcinoma (DTC). The purpose of this retrospective study was to compare the clinical usefulness of DRS, which is based on the response to initial treatment, with that of ATA initial risk stratification in pediatric patients.

Methods

A total of 144 pediatric patients underwent thyroid operation from August 1982 to December 2013 at Yonsei University Hospital (Seoul, Korea). Among them, 128 patients with complete clinical data were enrolled in this study. Clinicopathologic features and surgical outcomes were retrospectively analyzed by medical chart review. The mean follow-up duration was 11.5 years.

Results

The mean tumor size was 2.1 cm; 80.4% of patients were diagnosed with conventional papillary thyroid carcinoma, and 7.0% of patients were diagnosed with follicular thyroid carcinoma. Low-risk patients had the highest probability of an excellent response to initial treatment (66.6%). High-risk patients had the highest probability of a structural incomplete response (100%) and the lowest probability of an excellent response (11.1%). The ATA risk stratification and the DRS system were independent risk factors for disease-free survival (DFS) (P = 0.041 and P < 0.001, respectively).

Conclusion

The DRS system, which is based on the response to initial treatment, can offer more useful prognostic information compared with ATA risk stratification in pediatric patients with DTC.

Differentiated thyroid cancer in children: Heterogeneity of predictive risk factors

OBJECTIVE

To correlate clinical and pathological characteristics at diagnosis with patient long-term outcomes and to evaluate ongoing risk stratifications in a large series of paediatric differentiated thyroid cancers (DTC).

STUDY DESIGN

Retrospective analysis of clinical and pathological prognostic factors of 124 paediatric patients with DTC (age at diagnosis <19 years) followed up for 10.4 ± 8.4 years. Patients with a follow-up >3 years (n = 104) were re-classified 18 months after surgery on the basis of their response to therapy (ongoing risk stratification).

RESULTS

Most patients had a papillary histotype (96.0%), were older than 15 years (75.0%) and were diagnosed because of clinical local symptoms (63.7%). Persistent/recurrent disease was present in 31.5% of cases during follow-up, but at the last evaluation, only 12.9% had biochemical or structural disease. The presence of metastases in the lymph nodes of the lateral compartment (OR 3.2, 95% CI, 1.28-7.16, P = 0.01) was the only independent factor associated with recurrent/persistent disease during follow-up. At the last evaluation, biochemical/structural disease was associated with node metastases (N1a, N1b) by univariate but not multivariate analysis. Ongoing risk stratification compared to the initial risk classification method better identified patients with a lower probability of persistent/recurrent disease (NPV = 100%).

CONCLUSIONS

In spite of the aggressive presentations at diagnosis, paediatric patients with DTC show an excellent response to treatment and often a favourable outcome. N1b status should be considered a strong predictor of persistent/recurrent disease which, as in adults, is better predicted by ongoing risk stratification.