Differentiated thyroid cancer in children: Heterogeneity of predictive risk factors

Prognostic implications of lymph node yield in pediatric patients with N1b papillary thyroid cancer

OBJECTIVE

To investigate whether lymph node (LN) yield influences clinical outcomes for pediatric patients with laterocervical lymph node metastasis (N1b) from papillary thyroid cancer (PTC).

METHODS

Conducted from January 1, 2008, to December 31, 2022, this was a cohort study of pediatric patients (aged ≤ 18 years) with N1b PTC who underwent total thyroidectomy and therapeutic LN dissection in the central and lateral compartments at 3 hospitals in southwest China in 2008-2021, with follow-up until 2022. Patients with distant metastasis were excluded. Univariate and multivariate Cox proportional hazards regression analyses were used to identify factors associated with persistent/recurrent diseases.

RESULTS

A total of 102 pediatric patients (median [range] age, 16 [6-18] years) were analyzed: 36 patients (35 %) with T1; 27 patients (26 %), T2; 18 patients (18 %), T3; and 21 patients (21 %), T4. During a median follow-up of 50 months (range, 12-154 months), persistent diseases occurred in 40 (39 %) patients. Receiver operating characteristic analysis identified LN yield cut-off (<42 LNs) to predict persistent diseases. Multivariate analysis revealed that a less-extensive lymphadenectomy (<42 LNs) was an independent risk factor for persistent diseases (hazard ratio, 2.4; 95 % confidence intervals, 1.09-5.29; P=.029).

CONCLUSIONS

Our study highlights that a higher LN yield may favorably influence prognosis in pediatric patients with N1b PTC.

Prognostic Value of Tumor Multifocality in Pediatric Papillary Thyroid Carcinoma: A Real-Life Multicentric Study

OBJECTIVE

To investigate the association of multifocality with clinical outcomes in pediatric papillary thyroid cancer.

STUDY DESIGN

Multicenter retrospective study of prospectively collected data.

SETTING

Tertiary referral center.

METHODS

This study included patients 18 years or younger who underwent total thyroidectomy and radioiodine ablation for papillary thyroid carcinoma (PTC) between 2005 and 2020 at 3 tertiary adult and pediatric hospitals in China. For disease-free survival (DFS), events were defined as persistent and/or recurrent diseases. The primary outcome was the association of tumor multifocality and DFS, assessed using Cox proportional hazards regression models.

RESULTS

One hundred and seventy-three patients (median age 16 years [range, 5-18 years]) were recruited. Multifocal diseases were seen in 59 patients (34.1%). After a median follow-up of 57 (range, 12-193 months) months, 63 (36.4%) patients had persistent diseases. There was a significant association between tumor multifocality and decreased DFS on univariable analysis (hazard ratio [HR] = 1.90, p = .01), yet it was nonsignificant after multivariate adjustment (HR = 1.20, p = .55). In a subgroup analysis of 132 pediatric patients with clinically M0 PTC, neither unadjusted HR (2.21, p = .06) nor adjusted HR (1.70, p = .27) of multifocal PTC was significantly higher in comparison to unifocal PTC.

CONCLUSION

In this highly selective surgical pediatric patient cohort with PTC, tumor multifocality was not an independent risk factor for decreased DFS.

Outcomes of ATA Low-Risk Pediatric Thyroid Cancer Patients Not Treated With Radioactive Iodine Therapy

CONTEXT

The American Thyroid Association (ATA) Pediatric Guidelines recommend patients not receive radioactive iodine therapy (RAIT) for differentiated thyroid cancer (DTC) confined to the thyroid. Since publication, there is ongoing concern whether withholding RAIT will result in a lower rate of remission.

OBJECTIVE

This study explores whether ATA low-risk patients treated with and without RAIT achieved similar remission rates.

METHODS

Medical records of patients <19 years old diagnosed with DTC and treated with total thyroidectomy between 2010 and 2020 were reviewed. Multivariate logistic regression was performed to evaluate factors influencing RAIT administration and remission rate.

RESULTS

Ninety-five patients with ATA low-risk DTC were analyzed: 53% (50/95) and 47% (45/95) were treated with and without RAIT, respectively. RAIT was used to treat 82% of patients before 2015 compared with 33% of patients after 2015 (P < .01). No significant difference in 1-year remission rate was found between patients treated with and without RAIT, 70% (35/50) vs 69% (31/45), respectively. With longer surveillance, remission rates increased to 82% and 76% for patients treated with and without RAIT, respectively. Median follow-up was 5.8 years (IQR 4.3-7.9, range 0.9-10.9) and 3.6 years (IQR 2.7-6.6; range 0.9-9.3) for both cohorts. No risk factors for persistent or indeterminate disease status were found, including RAIT administration, N1a disease, and surgery after 2015.

CONCLUSION

Withholding RAIT for pediatric patients with ATA low-risk DTC avoids exposure to radiation and does not have a negative impact on remission rates. Dynamic risk stratification at 1-year after initial treatment is a suitable time point to assess the impact of withholding RAIT for these patients.

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.

Differentiated Thyroid Cancer in Children and Adolescents: Long Term Outcome and Risk Factors for Persistent Disease

Simple Summary

Despite their excellent prognosis, pediatric differentiated thyroid cancers (P-DTC) often undergo aggressive treatment due to the advanced disease presentation. Reliable risk stratification tools to guide management are needed; unfortunately, the current American Thyroid Association (ATA) classification for P-DTC lacks an unequivocal definition of the three risk categories. In line with previous work, our data confirm a favorable long-term outcome in P-DTC including cases with distant metastases. We propose a modified ATA pediatric risk stratification using a cut-off of five lymph nodes as proposed by the 2015 ATA guidelines for adult DTC. The modified pediatric ATA risk class independently predicted short- and long-term outcome. The utility of applying dynamic risk classification was also confirmed as P-DTC with an excellent response seldom experiences relapse.

Abstract

Background: Pediatric differentiated thyroid cancer (P-DTC) frequently presents with advanced disease. The study aim was to evaluate the outcome of P-DTC and a modified 2015 American Thyroid Association risk classification (ATA-R). Methods: A retrospective study of consecutive P-DTC patients was performed. The ATA-R for P-DTC was used with a cut-off of ≤ 5 N1a for low-risk. The outcome could be excellent response (ER) (thyroglobulin < 1 ng/mL and no evidence of disease (EoD) at imaging), biochemical incomplete response (BIR) (thyroglobulin ≥ 1 ng/mL and no EoD at imaging) or structural incomplete response (SIR) (EoD at imaging). Results: We studied 260 P-DTC (70% females; median age at diagnosis 14 years; 93% total thyroidectomy and 82% lymph node dissection). The ATA-R was low in 30% cases, intermediate in 15% and high in 55%, including 31.5% with distant metastases. Radioiodine treatment was administered in 218 (83.8%), and further radioiodine and surgery was performed in 113 (52%) and 76 (29%) patients, respectively. After a median follow-up of 8.2 years, the outcome was ER in 193 (74.3%), BIR in 17 (6.5%) and SIR in 50 (19.2%). Independent predictors of SIR or BIR at first and last visits were ATA-R intermediate or high. Conclusion: P-DTC has an excellent prognosis. Modified ATA-R is a useful prognostic tool in P-DTC to guide management.

Treating papillary and follicular thyroid cancer in children and young people: Single UK-center experience between 2003 and 2018

AIM

Differentiated thyroid cancer (DTC) in children and adolescents is rare and data about its presentation and management are not well known. The aim of this study was to provide evidence of the current practice in the United Kingdom before the launch of the Rare National Paediatric Endocrine Tumours Guidelines (to be published in 2020).

METHODS

Seventy-two children and adolescents with DTC (<18 years) who were treated at our institution between 2003 and 2018 were identified and their presentation, treatment and outcomes were reviewed.

RESULTS

Median age at presentation was 12.7 years [range: 1-18] and fifty-two (72%) were girls. Fifty (69.4%) children and adolescents presented with a thyroid nodule. Thirteen (18%) had cervical adenopathy and seven of them (54%) underwent an excision biopsy under GA. Eight patients (11%) had evidence of lung metastases at presentation. Twenty-four patients (33%) underwent a hemithyroidectomy and 22 of those had a completion thyroidectomy subsequently, ten (14%) a total thyroidectomy alone and 37 (51%) a total thyroidectomy with lymph nodes dissection. Seventy patients (97%) underwent adjuvant RAI at our institution. The median number of children and adolescents managed per year was five [range: 0-10]. After an overall median follow-up of 40 months, eight patients (11%) had developed recurrent disease. The 1- and 5-year recurrence-free-survival-rates were 93% and 87%, respectively. Overall survival was 100%, with eight children and adolescents (11%) being alive with disease.

CONCLUSION

This study confirms that DTC in children and adolescents is uncommon, is frequently advanced at presentation and has considerable recurrence rates. Despite this, overall survival is excellent. Although the work-up was generally appropriate (image-guided cytology), open biopsy for the diagnosis of lymph node involvement was still employed. The introduction of a specific UK guideline for this age-group will likely result in more tailored-made treatment-pathways and thereby hopefully improve quality and outcomes even further.

TYPE OF STUDY

Prognosis study.

LEVEL OF EVIDENCE

Level IV.

Performance of the American Thyroid Association Risk Classification in a Single Center Cohort of Pediatric Patients with Differentiated Thyroid Cancer: A Retrospective Study

Introduction

Differentiated thyroid cancer (DTC) is the most common endocrine malignancy in children. Retrospective studies show conflicting results regarding predictors of persistent and recurrent disease after initial therapy. In 2015, the American Thyroid Association (ATA) proposed a clinical classification system to identify pediatric thyroid cancer patients at risk for persistent/recurrent disease.

Material and Methods

We retrospectively included all patients in our registry diagnosed with papillary DTC at ≤ 18 years of age. We analyzed the prognostic performance of the ATA classification and other risk factors for predicting response to initial treatment and final outcome in pediatric DTC.

Results

We included 41 patients, 34 females and 7 males, diagnosed with papillary DTC at a mean (SD) age of 16.2 (1.8) years. Based on the ATA pediatric risk classification, patients were categorized as low (61%), intermediate (10%), or high risk (29%). The median follow-up period was 7.3 (1-41) years. After initial treatment, disease free status was achieved in 92%, 50%, and 42% of the low, intermediate, and high risk groups, respectively (P <0.01). At the last visit, persistent disease was present in 12%, 25%, and 33% (P=0.27). Assessing other risk factors, only the presence of distant metastases at diagnosis resulted in increased presence of persistent disease at last follow-up (P=0.03).

Conclusion

This study supports the clinical relevance of the ATA risk classification for predicting the response to initial treatment. There was no clear prediction of long-term outcome, but this may be due to limited power caused by the small number of patients.

Pediatric Differentiated Thyroid Cancer: Our Experience

Objectives: To report our experience in the management of thyroid cancer in children and adolescents in a tertiary referral hospital and regional cancer institute as compared to previously published data.

Methods: A retrospective study was conducted for patients diagnosed with differentiated thyroid cancer (DTC) who received treatment during the period from January 2014 to August 2018. Medical reports from our hospital database were extracted and information of those under 18 years old were discussed regarding their demographics, treatment received, and follow-up outcomes.

Results: Out of 300 patients with DTC diagnosed in the period of study, 12 were 18 years old or less (4%). Female to male ratio was 5:1. Their ages ranged from nine to 18 years old (average: 13.1 years). One patient had a positive family history for DTC, and one patient had lung metastasis. Total thyroidectomy and postoperative ¹³¹I were performed for all patients. The median follow-up period was 1.75 years (range: six months to four years). Eleven patients have shown complete remission after treatment (91.6%), and one case has had persistent disease.

Conclusions: Pediatric thyroid cancer is not uncommon. Despite its aggressiveness in this age group, outcomes are more favorable than in adults. We report our experience in the diagnosis and management of pediatric DTC in our community with satisfactory outcomes and comparable results to literature reports. Future studies are needed to evaluate the long-term complications of radioiodine therapy.

Differentiated Thyroid Carcinoma in Pediatric Age: Genetic and Clinical Scenario

Introduction: Follicular-derived differentiated thyroid carcinoma (DTC) is the most common endocrine and epithelial malignancy in children. The differences in the clinical and pathological features of pediatric vs. adult DTC could relate to a different genetic profile. Few studies are currently available in this issue, however, and most of them involved a limited number of patients and focused mainly on radiation-exposed populations. Materials and Methods: We considered 59 pediatric patients who underwent surgery for DTC between 2000 and 2017. RET/PTC rearrangement was investigated with fluorescent in situ hybridization and real-time polymerase chain reaction. Sequencing was used to analyze mutations in the BRAF, NRAS, PTEN, PIK3CA genes, and the TERT promoter. The pediatric patients' clinical and molecular features were compared with those of 178 adult patients. Results: In our pediatric sample, male gender and age <15 years coincided with more extensive disease and more frequent lymph node and distant metastases. Compared with adults, the pediatric patients were more likely to have lymph node and distant metastasis, and to need second treatments (p < 0.01). In all, 44% of the pediatric patients were found to carry molecular alterations. RET/PTC rearrangement was confirmed as the most frequent genetic alteration in childhood DTC (24.6%) and correlated with aggressive features. BRAFV600E was only identified in 16% of the pediatric DTCs, while NRASQ61R, NRASQ61K, and TERTC250T mutations were very rare. Conclusions: Pediatric DTC is more aggressive at diagnosis and more likely to recur than its adult counterpart. Unlike the adult disease, point mutations have no key genetic role.