Pediatric papillary thyroid carcinoma: outcomes and survival predictors in 2504 surgical patients

Construction and validation of a nomogram for predicting lateral lymph node metastasis in pediatric and adolescent with differentiated thyroid carcinoma

BACKGROUND

Limited research has been conducted to specifically investigate the identification of risk factors and the development of prediction models for lateral lymph node metastasis (LNM) in pediatric and adolescent differentiated thyroid carcinoma (DTC) populations, despite its significant association with unfavorable prognosis.

METHODS

This study entails a retrospective analysis of the clinical characteristics exhibited by pediatric and adolescent patients who have been diagnosed with DTC. The data utilized for this analysis was sourced from the Surveillance, Epidemiology, and End Results (SEER) database, spanning the time frame from 2000 to 2020. Furthermore, the study incorporates patients who were treated at the Departments of Breast and Thyroid Surgery in the Second Clinical Medical College, Affiliated Fifth People's Hospital of Chengdu University of Traditional Chinese Medicine, as well as The General Hospital of Western Theater Command, during the period from 2010 to 2020.

RESULTS

A cohort of 2631 patients from the SEER database, along with an additional 339 patients from our departments who met the specified inclusion criteria, were included in this study. Subsequently, four clinical variables, namely age, tumor size, multifocality, and extrathyroidal invasion, were identified as being significantly associated with lateral LNM in pediatric and adolescent DTC patients. These variables were then utilized to construct a nomogram, which demonstrated effective discrimination with a concordance index (C-index) of 0.731. Furthermore, the performance of this model was validated through both internal and external assessments, yielding C-index values of 0.721 and 0.712, respectively. Afterward, a decision curve analysis was conducted to assess the viability of this nomogram in predicting lymph node metastasis.

CONCLUSION

The current investigation has effectively constructed a nomogram model utilizing visualized multipopulationsal data. Our findings demonstrate a significant association between various clinical characteristics and lateral LNM in pediatric and adolescent DTC patients. These outcomes hold substantial significance for healthcare practitioners, as they can employ this model to inform individualized clinical judgments for the pediatric and adolescent cohorts.

Imaging findings of children with PTEN-related hamartoma tumor syndrome: a 20-year multicentric pediatric cohort

BACKGROUND

PTEN-related hamartoma tumor syndrome results from a mutation in the PTEN gene located at 10q23.31. This syndrome represents a spectrum of different phenotypes of variable expressions, now recognized as part of the same condition. Patients with this mutation have an increased risk of developing a wide range of findings, including malignancies. Although widely described in adults, there are no large series describing the imaging findings in patients before adulthood. Knowledge of the findings seen in children and adolescents with PTEN-related hamartoma tumor syndrome can help guide further management and improve surveillance recommendations.

OBJECTIVE

To describe the spectrum of imaging abnormalities in pediatric patients with PTEN-related hamartoma tumor syndrome.

MATERIALS AND METHODS

We performed a retrospective, cross-sectional, multicenter study conducted between January 2000 and October 2021 in three tertiary pediatric institutions evaluating the imaging findings in children and adolescents (≤ 18 years) with confirmed diagnoses of a PTEN mutation. For each patient, the imaging findings, histopathology reports, and at least a 2-year follow-up of clinical outcomes for non-operative cases were documented.

RESULTS

The cohort included 78 children (37 girls), with a mean age at diagnosis of 7.5 years (range 0 days to 18 years). Benign brain findings included enlarged Virchow-Robin perivascular spaces, white matter changes, developmental venous anomalies, and cerebellar hamartomas. Benign thyroid findings were common, but 5/45 (11.1%) with thyroid abnormalities had a malignant nodule. Soft tissue adipocytic tumors, GI/GU polyps, other soft tissue abnormalities, along with vascular anomalies in various anatomic locations were common.

CONCLUSION

Brain abnormalities, benign non-vascular soft tissue abnormalities, and vascular anomalies are commonly seen in children and adolescents with PTEN-related hamartoma tumor syndrome. However, malignancies involving the thyroid gland are not uncommon. Familiarity with the phenotype of PTEN-related hamartoma tumor syndrome in the pediatric population can improve diagnosis and prompt appropriate clinical surveillance of abnormal findings that warrant further management.

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.

Global incidence and prevalence of differentiated thyroid cancer in childhood: systematic review and meta-analysis

Objective

Differentiated thyroid cancer (DTC) is rare in childhood and adolescence although it represents the most frequent endocrine malignancy in this population. DTC includes both papillary thyroid carcinoma (PTC) and follicular thyroid carcinoma (FTC). Most pediatric DTCs are PTCs, while FTCs are rare. To date, no systematic reviews on the global epidemiology of pediatric and adolescent DTC have been published. This systematic review and meta-analysis aims to estimate the overall incidence and prevalence of DTCs in patients aged 0-19 years.

Methods

The systematic research was conducted from January 2000 to December 2021 through MEDLINE via PubMed, Cochrane Library, and Embase databases. Two separate meta-analyses were performed for PTC and FTC.

Results

After the selection phase, a total of 15 studies (3,332 screened) met the inclusion criteria and are reported in the present systematic review. Five studies were conducted in Europe, five in North America, two in South America, one in Asia, one reported data for 49 countries and territories across the five continents, and one from both the USA and Africa. Most of the studies (n = 14) reported data obtained from national registries, and only one provided information collected from hospital medical records. Beyond the actual trend over time, our study reported a pooled global incidence rate (IR) of PTC and FTC in the pediatric age of 0.46 (95% CI: 0.33-0.59) and 0.07 (95% CI: 0.02-0.12) per 100,000 person-years, respectively. The highest IRs were recorded among Caucasian girls, and the lowest in black or other races/ethnicities.

Conclusion

Our data confirm that DTC in the pediatric population is a rare condition. The pooled IRs of the studies included in this meta-analysis are ~0.5 for PTC, which is the most common histological type when both genders and all age groups are considered. The implementation of a prospective international registry on pediatric DTC, as part of the wider European Registries for Rare Endocrine Conditions, has been recently proposed. In addition to providing relevant information on the clinical behavior of this rare disease, standardization of data collection will be pivotal to fill current gaps and allow an accurate estimation of the real incidence and risk factors of DTC.

Thyroid Nodules and Follicular Cell-Derived Thyroid Carcinomas in Children

Although pediatric thyroid tumors have many similarities to those occurring in adults, significant differences are also recognized. For example, although thyroid nodules in children are much less common than in adults, a higher percentage is malignant. Moreover, while pediatric papillary thyroid carcinoma (PTC) is associated with more advanced disease, death due to disease in children and adolescents is very rare, even when distant metastases are present. Some subtypes of thyroid carcinoma, like diffuse sclerosing variant, are especially common in children and adolescents. Moreover, certain histologic findings, such as a tall cell morphology or increased mitotic activity, may not carry the same prognostic significance in children as in adults. Recent studies exploring the molecular underpinnings of pediatric thyroid carcinoma indicate that while driver alterations of thyroid tumorigenesis in children and adults are essentially the same, they occur at very different frequencies, with translocation-associated tumors (most commonly harboring RET and NTRK fusions) comprising a sizable and distinct group of pediatric PTC. DICER1 mutations, an infrequent mutation in adult thyroid tumors, are relatively frequent in pediatric encapsulated follicular-patterned thyroid tumors (with or without invasion or nuclear features of PTC). Additionally, tumor predisposition syndromes (most notably DICER1 syndrome and PTEN hamartoma tumor syndromes such as Cowden syndrome) should be considered in children with thyroid tumors, especially follicular-patterned thyroid tumors and poorly differentiated thyroid carcinoma. This review will explore the current state of knowledge of thyroid nodules and carcinomas in children and adolescents.

Varying impact of patient age on the rising rate of pediatric thyroid cancer: Analysis of NCDB database (2004-2017)

Pediatric thyroid carcinoma is on the rise. We sought to better characterize patient factors associated with this and evaluate for trends based on age groups. Additionally, we examined surgical management over time, and whether it aligns with recommendations made by the American Thyroid Association. Using the National Cancer Database (NCDB), we examined cases of thyroid cancer from 2004 to 2017, ages 1-18 years. We subdivided this cohort by age group: those <10y, 10-15y, and >15y. NCDB query yielded 5,814 cases. The annual proportion of total cases ranged from 3% to 8% for <10y, 31%-40% for 10-15y, and 52%-66% for >15y. 80-90% of cases in all age groups did indeed receive total thyroidectomy which is consistent with ATA guidelines. Our results verify an overall increase in pediatric thyroid cancer cases, occurring mostly in the 10-18 years old age range with the largest year-to-year increases in the >15y group.

Comparison of ultrasonography and pathology features between children and adolescents with papillary thyroid carcinoma

Objective

To compare the ultrasonography and pathology features between children and adolescents with papillary thyroid carcinoma (PTC).

Methods

A total of 53 patients who were surgically diagnosed with childhood or adolescent PTC between 2017 and 2022 were included in this study. The pre-operative ultrasonography, post-operative histology, and molecular and clinical characteristics were retrospectively analyzed.

Results

No differences were observed in composition, echogenicity, and shape using ultrasonography. Moreover, there was a significantly higher rate of extrathyroidal extension, punctate echogenic foci, and lymph node metastases in children compared to adolescents. The molecular analysis showed that BRAF^V600E mutations are the most prevalent abnormality in adolescent PTC (12/20, 60.0%). However, they are less in childhood PTC (7/23, 30.4%). In addition, using next-generation sequencing, three cases with oncogenic fusion (one TRIM33-RET case, one CCDC6-RET case, and one STRN-ALK case) were identified in childhood PTC.

Conclusion

The frequency of extrathyroidal extension, punctate echogenic foci, and lymph node metastases were higher in childhood PTC, while BRAF^V600E mutations were higher in adolescent PTC.

Fourteen years old as the best age cutoff to differentiate prepubertal from pubertal papillary thyroid carcinoma

BACKGROUND

It is unclear whether differences in clinical presentation and/or prognosis exist between prepubertal papillary thyroid cancer (PTC) and pubertal PTC. At present, there is a lack of definition for the appropriate cutoff age to define prepubertal PTC.

METHODS

This study retrospectively reviewed 227 pediatric PTC patients (aged ≤18 years) who underwent initial surgery from March 2000 to December 2018. The median duration of follow-up was 85 months (range, 8-258).

RESULTS

The age range was basically linearly related to multiple risk factors, such as T3-T4 disease, distant metastasis. Age (p = 0.032) was an independent risk factor for recurrence and persistent disease. Patients aged <14 years had obviously higher rates of extensive disease. The 10-year disease-free survival (DFS) rate of patients aged <14 years was 59.5% and that of patients aged ≥14 years was 82.6% (p = 0.004).

CONCLUSIONS

Fourteen years of age may be an appropriate cutoff to differentiate prepubertal PTC from pubertal PTC.

Pediatric thyroid cancer: Recent developments

Thyroid cancer is rare in children but its incidence is increasing. Recent data have clarified important similarities and differences between thyroid cancers originating in childhood and in adulthood. The genetic drivers of pediatric thyroid cancers are similar to those in adult tumors but comprise more gene fusions and fewer point mutations. Clinically, despite frequent metastatic spread, pediatric thyroid cancer has an excellent prognosis and mortality is rare. Therefore, treatment approaches must weigh carefully the morbidity of thyroid cancer treatments against their benefits. Current key questions include which children require total thyroidectomy rather than more limited-and safer-lobectomy, and in which children does the benefit of radioactive iodine therapy outweigh its risk of inducing a secondary malignancy. Finally, molecular therapies targeting genetic drivers of thyroid cancer now provide effective treatment for children with progressive, radioiodine-refractory disease, as well as opportunities to explore novel neoadjuvant uses that facilitate therapeutic surgery or radioactive iodine.

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.

Sociodemographic Disparities in the Diagnostic Management of Pediatric Thyroid Nodules

Importance

Thyroid cancer is the most common pediatric endocrine malignant neoplasm. Disparities in the workup of thyroid nodules may be significantly associated with thyroid cancer outcomes.

Objective

To determine the association of sociodemographic factors with the odds of receiving a biopsy, timeliness of the procedure, and risk of nodule malignancy.

Design, Setting, and Participants

This was a retrospective cross-sectional study using insurance claims data from the Optum Clinformatics Data Mart database. The study cohort comprised pediatric patients diagnosed with single thyroid nodules between 2003 and 2020. Data analysis was performed from January 1, 2003, to June 30, 2020.

Main Outcomes and Measures

Multivariable logistic regression models were used to identify demographic variables associated with biopsy and nodule malignant neoplasm. A multivariable linear regression model was used to assess the time between thyroid nodule diagnosis and biopsy.

Results

Of 11 643 children (median [IQR] age at diagnosis or procedure, 15 [12-17] years; 8549 [73.2%] were female and 3126 [26.8%] were male) diagnosed with single thyroid nodules, 2117 (18.2%) received a biopsy. Among the patients who received a biopsy, 304 (14.4%) were found to have a malignant nodule. Greater parental education was associated with a shorter diagnosis-to-biopsy interval (mean difference, -7.24 days; 95% CI, -13.75 to -0.73). Older age at nodule diagnosis (odds ratio [OR], 1.11; 95% CI, 1.09-1.13) and female gender (OR, 1.25; 95% CI, 1.11-1.40) were associated with increased odds of receiving a biopsy, while Black/African American (OR, 0.80; 95% CI, 0.65-0.99) and Hispanic (OR, 0.84; 95% CI, 0.72-0.99) patients had lower odds of receiving a biopsy compared with White patients. Finally, female gender (OR, 1.08; 95% CI, 0.80-1.47) was not associated with lower odds of nodule malignant neoplasm.

Conclusions and Relevance

Findings of this cross-sectional study highlight disparities in the diagnostic management of pediatric thyroid nodules. These results call for future work to ensure equitable access to thyroid care for all children.

Risk factors for lateral lymph node metastasis of papillary thyroid carcinoma in children

INTRODUCTION

Lateral cervical lymph node metastases (LNM) for pediatric patients with papillary thyroid cancer (PTC) is a poor prognostic factor. We aimed to identify risk factors for lateral LNM.

METHODS

This retrospective study had included 48 pediatric patients with papillary thyroid cancer underwent total thyroidectomy and central cervical lymphadenectomy at K hospital from 2016 to 2020.

RESULTS

The number of patients in each T stage was as follows: 24 (50.0%) in stage 1, 9 (18.7%) in Stage 2, 8 (16.7%) in Stage 3, and 7 (14.6%) in Stage 4. Most of the patients had LNM with N1a and N1b rates of 83.3% and 62.5%, respectively. Lung metastases were observed at presentation in three patients (6.3%). Univariate analysis revealed that age (p = 0.021), male (p = 0.011), tumor size > 10 mm (p = 0.002), multifocality (p < 0.001), extrathyroidal extension (p = 0.001) and central LNM (p < 0.001) were factors that increase the risk of metastasis to lateral LNM.

CONCLUSION

Approximately 62.5% of pediatric patients with PTC exhibited lateral LNM at the time of diagnosis. Our study confirmed that multifocality, maximum tumor diameter, extrathyroidal extension and central LNM were independent risk factors for lateral LNM in pediatric PTC.

LEVEL OF EVIDENCE

Level IV.

Perioperative outcomes of thyroid cancer surgery in children and adults: a nationwide inpatient database study in Japan

BACKGROUND

Little is known about perioperative outcomes after pediatric thyroidectomy. This study was performed to compare perioperative outcomes between children and adults undergoing thyroid cancer surgery using a nationwide inpatient database in Japan.

METHODS

Using the Japanese Diagnosis Procedure Combination database, we identified patients aged 0 to 40 years with thyroid cancer who underwent thyroidectomy from July 2010 to March 2020. To compare the occurrence of in-hospital morbidities including local complications (e.g., recurrent laryngeal nerve paralysis, postoperative bleeding), duration of anesthesia, postoperative length of stay, and total hospitalization costs between children (0-18 years) and adults (19-40 years), we used multivariable logistic regression analysis for the occurrence of in-hospital morbidities and linear regression for other outcomes.

RESULTS

For 16,016 eligible patients (666 children vs. 15,350 adults), no significant differences between the two groups were found in any in-hospital morbidity (5.4% vs. 5.9%; adjusted odds ratio [OR], 0.80; 95% confidence interval [CI], 0.57-1.14; P = 0.23), local complications (5.0% vs. 5.5%; OR, 0.80; 95% CI, 0.55-1.15; P = 0.22), recurrent laryngeal nerve paralysis (2.1% vs. 2.4%; OR, 0.78; 95% CI, 0.45-1.35; P = 0.37), or postoperative bleeding (1.7% vs. 1.4%; OR, 0.99; 95% CI, 0.53-1.87; P = 0.98). Children showed a longer duration of anesthesia (difference, 20 minutes; 95% CI, 13-27; P < 0.001) and higher total costs (difference, 445 US dollars; 95% CI, 239-651; P < 0.001) than adults.

CONCLUSION

This large nationwide cohort study showed no significant difference in perioperative complications between children and adults undergoing thyroid cancer surgery.

Effect of Suppressive Levothyroxine Therapy on Bone Mineral Density in Young Patients with Differentiated Thyroid Carcinoma

Suppressive levothyroxine therapy (sT4) is a cornerstone in the management of differentiated thyroid cancer (DTC). Long-term sT4 may affect bone mineral density (BMD). We evaluated the effect of sT4 on the bone mass of young DTC patients. In this cross-sectional study, BMD was evaluated via dual-energy X-ray absorptiometry in DTC patients younger than 25 years at diagnosis and undergoing sT4 for ≥1 year. The two control groups comprised patients matched for sex, age, and body-mass-index who were thyroidectomized for indications other than DTC and undergoing L-T4-replacement therapy, and healthy individuals with no prior known thyroid disease. Ninety-three participants were included (thirty-one in each group). There were no differences in the mean age, female sex (77.4% in all groups), or BMI between the sT4 group and each control group. The median TSH level was lower (0.4 [0.04–6.5] vs. 2.7 [0.8–8.5] mIU/mL, p = 0.01) and the mean L-T4 mcg/Kg levels were higher (2.4 ± 0.6 vs. 1.6 ± 0.3, p = 0.01) in the sT4 group compared to the L-T4-replacement therapy group. Lumbar spine, femoral neck, and total femur BMD were all similar among the groups. sT4 does not impact BMD in young DTC patients after a median time of suppression of 8 years. These findings may help in the decision-making and risk/benefit evaluation of sT4 for this population.

Prophylactic Central Neck Dissection to Improve Disease-Free Survival in Pediatric Papillary Thyroid Cancer

Background

Pediatric PTC is a rare disease. Although, the prognosis is excellent and the mortality rate is low, the role of prophylactic central neck dissection is still the subject of debate. The aim was to evaluate both the role and safety of prophylactic central neck dissection (CND) in managing pediatric papillary thyroid cancer (PTC), especially in respect of disease-free survival (DFS).

Patients and Methods

In this retrospective study, we collected 54 pediatric cN0 PTC patients (≤ 18 years of age) who were treated from January 2014 to January 2021 at a high-volume thyroid surgery center. Patients were divided into two groups based on the status of prophylactic CND. We analyzed the factors related to the clinicopathological features and recurrence of PTC in children.

Results

Of the 54 cN0 patients, 35 underwent prophylactic CND and 19 patients did not undergo prophylactic CND. The two groups were similar in clinical and pathologic features, such as age, gender, tumor size, multifocal status, and follow-up time. The average DFS was 84.4 ± 2.7 months. Log-rank tests on Kaplan-Meier curves revealed that age, gender, tumor size, multifocality, and extrathyroid extension did not relate to DFS time. Furthermore, DFS time was not affected by the extent of thyroidectomy (p=0.07) or RAI treatment (p=0.21). Prophylactic CND was found to increase DFS time for pediatric patients with cN0 PTC (p = 0.003). There was no statistically significant difference in complications such as transient hypocalcemia (p=0.15) and transient recurrent laryngeal nerve injury (p=0.37) between the prophylactic CND group and the no-prophylactic CND group.

Conclusion

Prophylactic CND was found to be associated with increased DFS and not with increased rates of complications after surgery.

Puberty and sex in pediatric thyroid cancer: could expression of estrogen and progesterone receptors affect prognosis?

OBJECTIVE

A sharp increase in pediatric thyroid cancer incidence is observed during adolescence, driven mainly by girls. Differences in disease presentation across sexual maturity stages raise the question of whether sex steroids have a role in the heterogeneity. The aims of this study were to analyze the influence of puberty and sex on clinical presentation and prognosis and to evaluate the correlation between the expression of sex hormone receptors.

DESIGN AND METHODS

Clinical records and immunohistochemical of specimens from 79 patients were analyzed. Puberty was analyzed by two criteria: end of puberty and beginning, in which the age of 10 was the cutoff.

RESULTS

Postpubertal were more frequently classified as having low-risk disease and a lower frequency of persistent disease, especially when the completion of puberty was used as the criteria. Male sex was associated with a higher risk of persistent disease at the end of the observation period. Estrogen receptor α positivity was low in the entire sample, while progesterone receptor positivity was positive in 30% of the cases. Female hormone receptor expression was not associated with sex, American Thyroid Association risk score, persistent structural disease, or pubertal status.

CONCLUSION

Our study showed that the completion of puberty correlated best with the clinical behaviour of pediatric thyroid cancer. It was also shown that postpubertal patients have a less aggressive initial presentation and better outcomes. However, this observation could not be explained by the expression of estrogen and progesterone receptors in the primary tumors.

DICER1 tumor predisposition syndrome: an evolving story initiated with the pleuropulmonary blastoma

DICER1 syndrome (OMIM 606241, 601200) is a rare autosomal dominant familial tumor predisposition disorder with a heterozygous DICER1 germline mutation. The most common tumor seen clinically is the pleuropulmonary blastoma (PPB), a lung neoplasm of early childhood which is classified on its morphologic features into four types (IR, I, II and III) with tumor progression over time within the first 4-5 years of life from the prognostically favorable cystic type I to the unfavorable solid type III. Following the initial report of PPB, its association with other cystic neoplasms was demonstrated in family studies. The detection of the germline mutation in DICER1 provided the opportunity to identify and continue to recognize a number seemingly unrelated extrapulmonary neoplasms: Sertoli-Leydig cell tumor, gynandroblastoma, embryonal rhabdomyosarcomas of the cervix and other sites, multinodular goiter, differentiated and poorly differentiated thyroid carcinoma, cervical-thyroid teratoma, cystic nephroma-anaplastic sarcoma of kidney, nasal chondromesenchymal hamartoma, intestinal juvenile-like hamartomatous polyp, ciliary body medulloepithelioma, pituitary blastoma, pineoblastoma, primary central nervous system sarcoma, embryonal tumor with multilayered rosettes-like cerebellar tumor, PPB-like peritoneal sarcoma, DICER1-associated presacral malignant teratoid neoplasm and other non-neoplastic associations. Each of these neoplasms is characterized by a second somatic mutation in DICER1. In this review, we have summarized the salient clinicopathologic aspects of these tumors whose histopathologic features have several overlapping morphologic attributes particularly the primitive mesenchyme often with rhabdomyoblastic and chondroid differentiation and an uncommitted spindle cell pattern. Several of these tumors have an initial cystic stage from which there is progression to a high grade, complex patterned neoplasm. These pathologic findings in the appropriate clinical setting should serve to alert the pathologist to the possibility of a DICER1-associated neoplasm and initiate appropriate testing on the neoplasm and to alert the clinician about the concern for a DICER1 mutation.

Prevalence and Risk Factors for Multifocality in Pediatric Thyroid Cancer

Importance

Current guidelines recommend total thyroidectomy for the majority of pediatric thyroid cancer owing to an increased prevalence of multifocality. However, there is a paucity of information on the exact prevalence and risk factors for multifocal disease-knowledge that is critical to improving pediatric thyroid cancer management and outcomes.

Objective

To determine the prevalence and risk factors for multifocal disease in pediatric patients with papillary thyroid carcinoma (PTC).

Design, Setting, and Participants

This multicenter retrospective cohort study included patients 18 years or younger who underwent thyroidectomy for PTC from 2010 to 2020 at 3 tertiary pediatric hospitals and 2 tertiary adult and pediatric hospitals in the US.

Main Outcomes and Measures

Demographic and clinical variables, including age, family history of thyroid cancer, autoimmune thyroiditis, prior radiation exposure, cancer predisposition syndrome, tumor size, tumor and nodal stage, PTC pathologic variant, and preoperative imaging, were assessed for association with presence of any multifocal, unilateral multifocal, and bilateral multifocal disease using multiple logistic regression analyses. Least absolute shrinkage and selection operator analysis was performed to develop a model of variables that may predict multifocal disease.

Results

Of 212 patients, the mean age was 14.1 years, with 23 patients 10 years or younger; 173 (82%) patients were female. Any multifocal disease was present in 98 (46%) patients, with bilateral multifocal disease in 73 (34%). Bilateral multifocal disease was more accurately predicted on preoperative imaging than unilateral multifocal disease (48 of 73 [66%] patients vs 9 of 25 [36%] patients). Being 10 years or younger, T3 tumor stage, and N1b nodal stage were identified as predictors for multifocal and bilateral multifocal disease.

Conclusions and Relevance

This large, multicenter cohort study demonstrated a high prevalence of multifocal disease in pediatric patients with PTC. Additionally, several potential predictors of multifocal disease, including age and advanced T and N stages, were identified. These risk factors and the high prevalence of multifocal disease should be considered when weighing the risks and benefits of surgical management options in pediatric patients with PTC.

Clinical and Molecular Characterizations of Papillary Thyroid Cancer in Children and Young Adults: A Multicenter Retrospective Study

Background: Papillary thyroid carcinoma (PTC) is a rare malignancy in children and young adults (CAYA). It often presents with aggressive disease patterns and advanced stages, which are clinically distinct from those in adult patients. In this study, we sought to characterize and better understand the clinical variants of PTC in CAYA and explore the underlying mechanisms. Methods: CAYA patients (age ≤18 years) diagnosed with PTC between June 2006 and June 2018 were retrospectively recruited from five hospitals. Demographic information, pathological data, and follow-up status were recorded. Tumor samples obtained from 20 children (mean age 15.15 years) and 10 adults (mean age 38.80 years) underwent comprehensive whole transcriptome sequencing. Differentially expressed genes (DEGs), mutational landscape, and immune infiltration were analyzed. Results: A total of 217 CAYA-PTC patients (162 females and 55 males) with an average age of 14.38 ± 3.53 years (range 2-18) were included. Lymph node metastasis (LNM) was observed in 85.71%, of which 57.60% were in the lateral cervical compartment. Disease recurred in 28 of 217 (12.90%) patients with a median follow-up of 4.76 years. Multivariate logistic regression analysis revealed that age, bilateral disease, extrathyroidal extension, and coexisting Hashimoto's thyroiditis (co-HT) were independent risk factors for LNM, while co-HT was the only risk factor for recurrence. Using whole transcriptome sequencing of PTC tissues, we identified 301 DEGs. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses showed that differences in immune mediators played important roles, based on the distributions of mutation frequencies, types, and expression levels between CAYA and adult patients. Based on the integrated data sets, we identified significantly mutated immune genes, cluster of differentiation 24 (CD24), coagulation factor 12 (F12), coagulation factor 5 (F5), integrin subunit alpha 3 (ITGA3), and retinoic acid early transcript 1L (RAET1L), which were then verified by immunohistochemistry. Furthermore, resting mast cells, resting natural killer cells, plasma cells, and regulatory T cells were different in the CAYA-PTC group and correlated with the expression of immune checkpoints. Conclusions: There are considerable variabilities that may contribute to the different clinical presentations between CAYA and adult PTC patients, among which the decrease in protective immune cells may be a factor. Collectively, our results add to the possible biological mechanisms involved in CAYA-PTC.

Opposite Incidence Trends for Differentiated and Medullary Thyroid Cancer in Young Dutch Patients over a 30-Year Time Span

Simple Summary

Thyroid cancer is a rare disease in childhood; however, its incidence is rising. Thyroid cancer consists of three main types: Papillary thyroid cancer (PTC), follicular thyroid cancer (FTC), and medullary thyroid cancer (MTC). The aim of our retrospective study was to investigate the incidence and survival trends of these three thyroid cancer types in Dutch children, adolescents, and young adults over a 30-year life span. In total, 839 patients aged 0–24 years had been diagnosed with thyroid cancer between 1990 and 2019. The incidence of PTC increased significantly over time, the incidence of FTC showed a stable trend, while the incidence of MTC decreased significantly. Overall, the 10-year survival rates over the last decades were high (>95%) for PTC, FTC, and MTC in young individuals.

Abstract

Thyroid cancer is the most common endocrine malignancy in children. A rising incidence has been reported worldwide. Possible explanations include the increased use of enhanced imaging (leading to incidentalomas) and an increased prevalence of risk factors. We aimed to evaluate the incidence and survival trends of thyroid cancer in Dutch children, adolescents, and young adults (0–24 years) between 1990 and 2019. The age-standardized incidence rates of differentiated thyroid cancer (DTC, including papillary and follicular thyroid cancer (PTC and FTC, respectively)) and medullary thyroid cancer (MTC), the average annual percentage changes (AAPC) in incidence rates, and 10-year overall survival (OS) were calculated based on data obtained from the nationwide cancer registry (Netherlands Cancer Registry). A total of 839 patients aged 0–24 years had been diagnosed with thyroid carcinoma (PTC: 594 (71%), FTC: 128 (15%), MTC: 114 (14%)) between 1990 and 2019. The incidence of PTC increased significantly over time (AAPC +3.6%; 95%CI +2.3 to +4.8), the incidence rate of FTC showed a stable trend ((AAPC −1.1%; 95%CI −3.4 to +1.1), while the incidence of MTC decreased significantly (AAPC: −4.4% (95%CI −7.3 to −1.5). The 10-year OS was 99.5% (1990–1999) and 98.6% (2000–2009) in patients with DTC and 92.4% (1990–1999) and 96.0% (2000–2009) in patients with MTC. In this nationwide study, a rising incidence of PTC and decreasing incidence of MTC were observed. For both groups, in spite of the high proportion of patients with lymph node involvement at diagnosis for DTC and the limited treatment options for MTC, 10-year OS was high.

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.

The Use of the Bethesda System for Reporting Thyroid Cytopathology in Pediatric Thyroid Nodules: A Meta-Analysis

Background: Little is known about the application of the Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) in pediatric thyroid nodules. This meta-analysis was aimed to investigate the use of TBSRTC in the pediatric population. Methods: Relevant articles were searched in PubMed and Web of Science. Meta-analysis of proportion and its 95% confidence interval (CI) were computed utilizing the random-effect model. We used subgroup analyses and meta-regression to explore the sources of heterogeneities. Egger's regression test and funnel plot visualization were used to examine publication bias. Results: We included 17 articles comprising of 3687 pediatric thyroid nodules for meta-analyses. TBSRTC outputs including frequency and risk of malignancy (ROM) for the majority of categories were not statistically different from recently published meta-analysis of 145,066 thyroid nodules in adult patients. The resection rate (RR) in the pediatric group was significantly higher in most of the categories compared with published adult data: benign, 23.2% [CI = 18.6-27.9] vs. 13.0% [CI = 9.5-16.5]; atypia of undetermined significance/follicular lesion of undetermined significance, 62.6% [CI = 50.3-74.9] vs. 36.2% [CI = 29.9-42.5]; follicular neoplasm/suspicious for follicular neoplasm, 84.3% [CI = 75.2-93.4] vs. 60.5% [CI = 54.5-66.5]; and suspicious for malignancy, 93.8% [CI = 90.1-97.6] vs. 69.7% [CI = 64.0-75.5]. Conclusion: TBSRTC is a valuable tool to make clinical decisions for pediatric patients with thyroid nodules. Pediatric patients with benign and indeterminate thyroid nodules had a higher RR than adult counterpart, but ROM of these categories in adults and children was not statistically different suggesting a potential risk of overtreatment in pediatric patients. Determining the best treatment guidelines and additional tools for risk stratification must be a top priority to precisely identify the target patient groups for surgical intervention.

Increasing incidence and survival of paediatric and adolescent thyroid cancer in Cyprus 1998-2017: A population-based study from the Cyprus Pediatric Oncology Registry

BACKGROUND

Paediatric and adolescent thyroid cancer incidence rates are increasing in many countries. We determined incidence rates, temporal trends and survival from thyroid cancer diagnosed in childhood and adolescence in Cyprus during 1998-2017.

METHODS

Patients aged 0-19 years, diagnosed with thyroid cancer in the Pediatric Oncology Registry of Cyprus were included. Crude incidence rates, age standardized rates, time trends and overall survival were analysed. Annual rates and temporal trends were calculated using Microsoft Excel 2016 and Joinpoint regression analysis.

RESULTS

Eighty-one cases (76.5 % female, 23.5 % male) were identified. The crude rates (per 100,000 persons) were for both sexes 2.00 (95 % CI 1.61, 2.49), females 3.15 (95 % CI 2.45, 4.03) and males 0.92 (95 % CI 0.58, 1.44). The annual percentage changes of crude and standardised rates were 7.5 % (p < 0.05) and 7.6 % (p < 0.05). The annual percentage changes of crude rates were for females 5.1 % (p = 0.1), males 8.4 % (p < 0.05) and 15-19-year-olds 7.6 % (p < 0.05). The female to male rate ratio was 3.42 (95 % CI 2.06, 5.74). Papillary thyroid carcinoma represented 86.4 % of all cases. There was only one case after previous cancer therapy. The rate ratio of 2nd (2008-2017) to 1st (1998-2007) periods for metastatic (regional) stages was 3.76 (95 % CI 1.74, 8.31). Survival until 2018 was 100 %.

CONCLUSION

This population-based study demonstrated that thyroid cancer incidence rates in 0-19-year-olds in Cyprus was among the world's highest. Increasing trends mainly affected males and females aged 15-19 years with papillary thyroid carcinoma, the dominant type. Cases after previous cancer therapy didn't contribute to increasing rates. The increase of metastatic cases suggests a true increase of thyroid cancer rather than overdiagnosis. Although prognosis is excellent with 100 % survival, the rising incidence rate is unexplained, indicating the need to identify causes.

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.

Application of the Bethesda System for Reporting Thyroid Cytopathology in the Pediatric Population

OBJECTIVES

We aimed to provide the Asian experience with the Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) in pediatric thyroid nodules.

METHODS

Consecutive thyroid fine-needle aspirates (patient age, ≤18 years) were retrospectively collected from 7 tertiary centers in 5 Asian countries.

RESULTS

Of 194,364 thyroid aspirates, 0.6% were pediatric cases (mean age, 15.0 years). Among 827 nodules with accessible follow-up, the resection rate and risk of malignancy (ROM) were 36.3% and 59.0%, respectively. Malignant nodules (n = 179) accounted for 59.7% of resected nodules and 21.6% of all thyroid nodules with available follow-up. Compared with the published adult series, pediatric nodules had a higher resection rate and ROM, particularly in the indeterminate categories.

CONCLUSIONS

Our study demonstrates that Asian pediatric thyroid nodules had higher ROM than those from adults. The prototypic outputs of TBSRTC may need to be adjusted in the pediatric population.

Distant Metastases From Childhood Differentiated Thyroid Carcinoma: Clinical Course and Mutational Landscape

CONTEXT

Distant metastases (DM) from childhood differentiated thyroid carcinoma (DTC) are uncommon and published studies are limited.

OBJECTIVE

This work aimed to describe the outcomes of patients with DM from childhood DTC and to evaluate the molecular landscape of these tumors.

METHODS

A retrospective study was conducted at a tertiary cancer center including patients with pediatric DTC (diagnosed at age ≤ 18 years from 1946 to 2019) and DM.

RESULTS

We identified 148 patients; 144 (97%) had papillary thyroid carcinoma (PTC) and 104 (70%) were female. Median age at DTC diagnosis was 13.4 years (interquartile range [IQR], 9.9-15.9 years). Evaluable individuals received a median of 2 (IQR, 1-3) radioactive iodine (RAI) treatments at a median cumulative administered activity of 238.0 mCi (IQR, 147.5-351.0 mCi). The oncogenic driver was determined in 64 of 69 PTC samples: RET fusion (38/64; 59%), NTRK1/3 fusions (18/64; 28%), and the BRAF V600E mutation (8/64; 13%). At last evaluation, 93% had persistent disease. The median overall and disease-specific survival after DTC diagnosis were 50.7 and 52.8 years, respectively. Eight (5%) PTC patients died of disease after a median of 30.7 years (IQR, 20.6-37.6 years).

CONCLUSION

Childhood DTC with DM persists in most patients despite multiple courses of RAI, but disease-specific death is uncommon, typically occurring decades after diagnosis. Fusion genes are highly prevalent in PTC, and all identified molecular alterations have appropriate targeted therapies. Future studies should focus on expanding genotype-phenotype correlations, determining how to integrate molecularly targeted therapy into treatment paradigms, and relying less on repeated courses of RAI to achieve cure in patients with DM from childhood DTC.

Case Report: Transoral Endoscopic Thyroidectomy via Vestibular Approach in Pediatric Thyroid Cancer

Background: Transoral endoscopic thyroidectomy via vestibular approach (TOETVA) is a new technique that has become more popular worldwide because of its many advantages. However, this novel approach for thyroid cancer treatment in children is highly challenging, even for high-volume surgeons. In our study, we report our experiences with TOETVA for pediatric patients with thyroid cancer. Patients and Methods: This study included four pediatric patients who underwent TOETVA performed by a single surgeon between June and December 2020. Patient demographics and surgical outcomes including operative time, incidence of complications, and length of hospital stay were evaluated. Results: Four patients successfully underwent TOETVA with no complications. All patients were girls, aged from 13 to 18. Three patients underwent lobectomy and isthmusectomy, plus prophylactic unilateral central neck dissection. One patient had a total thyroidectomy, plus prophylactic bilateral central neck dissection. The mean operative time was 85 min for the lobectomy and 120 min for total thyroidectomy plus central neck dissection. The median hospital stay was 4.1 days. No drains were used. The histological examination showed four cases of malignant disease (papillary thyroid carcinoma). The mean number of harvested lymph nodes was 4.2 (ranged 3 to 8). Conclusion: In the hands of a high-volume surgeon, TOETVA is a novel, feasible, and safe approach for treating selected pediatric patients with thyroid cancer.

Lung Metastasis in Children with Differentiated Thyroid Cancer: Factors Associated with Diagnosis and Outcomes of Therapy

Background: Lung metastasis from differentiated thyroid cancer (DTC) in children and young adults (CAYA) is estimated at 25%, which is 3-4 times higher than in adults. Lung metastases may respond to radioactive iodine (RAI) therapy and overall survival is excellent. Associations with lung metastasis include lateral lymph node (LN) disease although CAYA data are limited. We investigated factors associated with lung metastasis in children and adolescents and described their presentation and outcome. Methods: A retrospective review of medical records from 1998 to 2017 in patients aged <18 years treated at a tertiary pediatric center was carried out. Data on age, clinical features at diagnosis, histology, biochemistry, imaging, RAI therapy, and outcome were collected. Results: Patients treated for DTC totaled 98 and 19 of 98 (19%) patients had lung metastasis; 17 of 19 (89%) patients were identified within 6 months from thyroidectomy. Patients with lung metastasis were younger (p < 0.001)-40% <13 years old had lung metastasis-and had a larger primary tumor diameter (p = 0.01). Absence of LN disease had negative predictive values ≥90% (p < 0.02). Patients with lung metastasis had a higher postoperative thyrotropin-stimulated thyroglobulin (Tg) (p < 0.001), ≥2 ng/mL in 10 of 11 (91%) patients, and 100% had an elevated preoperative Tg (>60 ng/mL). Post-therapy whole body scan (WBS) identified most metastasis (13 of 17 patients), which were mostly diffuse (11 of 19 patients). Discordant findings were found between WBS and computed tomography (CT) at diagnosis (2 patients), WBS and CT during surveillance (3 patients), and diagnostic and post-therapy WBS (2 patients). Final outcome was "excellent" in 3 of 19 (16%) patients, "biochemically persistent" in 1 of 19 (5%) patients, "structurally persistent" in 13 of 19 (68%) patients-including 1 death-and indeterminate in 2 of 19 (11%) patients. Postoperative Tg correlated with response to therapy. Lung metastasis pattern and RAI cumulative activity were not predictive of response to therapy. Conclusions: Lung metastases are mostly observed at diagnosis of DTC and higher suspicion should be maintained in CAYA who are younger, have LN disease, and have elevated postoperative Tg. Preoperative Tg shows promise as another predictive marker, but limited sample size precludes generalization. "Excellent" response to therapy is uncommon-multiple RAI courses do not necessarily improve outcome-response appears unrelated to RAI activity or metastasis pattern.

Genetic Landscape of Papillary Thyroid Carcinoma and Nuclear Architecture: An Overview Comparing Pediatric and Adult Populations

Thyroid cancer is a rare malignancy in the pediatric population that is highly associated with disease aggressiveness and advanced disease stages when compared to adult population. The biological and molecular features underlying pediatric and adult thyroid cancer pathogenesis could be responsible for differences in the clinical presentation and prognosis. Despite this, the clinical assessment and treatments used in pediatric thyroid cancer are the same as those implemented for adults and specific personalized target treatments are not used in clinical practice. In this review, we focus on papillary thyroid carcinoma (PTC), which represents 80-90% of all differentiated thyroid carcinomas. PTC has a high rate of gene fusions and mutations, which can influence the histologic subtypes in both children and adults. This review also highlights telomere-related genomic instability and changes in nuclear organization as novel biomarkers for thyroid cancers.

Practice Patterns and Outcomes of Pediatric Thyroid Surgery: An NSQIP Analysis

BACKGROUND

Pediatric thyroid cancer rates are rising. The aim of this study was to determine the state of current practice and outcomes for pediatric thyroidectomies using the pediatric National Surgical Quality Improvement Program (NSQIP-P) with specific attention to differences based on surgeon type/specialty.

METHODS

All cases of pediatric thyroidectomies and neck dissections within the NSQIP-P database were identified from 2015 to 2017. Patient, disease, and treatment-related factors affecting 30-day outcomes were analyzed using univariate and multivariate analyses.

RESULTS

A total of 1300 cases were identified. Mean age at time of surgery was 14.0 (SD 3.5) years. The majority of patients were female (78%) and Caucasian (72%). Pediatric general surgeons performed the largest proportion of cases (42%) followed by pediatric otolaryngologists (33%). Malignancies were present in 29% of cases. The overall rate of complications was 3.0%. On multivariate analysis, non-pediatric surgeons were more likely to operate on Caucasian children, malignant pathology, and perform modified radical neck dissections. Pediatric surgeons were more likely to have longer operative times, have specialized in otolaryngology, and operate on sicker children (ASA>2). There were no differences in length of stay or overall complications rates.

CONCLUSIONS

This study shows that pediatric surgeons currently perform the majority of thyroid surgeries in children. While unable to assess surgeon volume, our data show that thyroid surgery is being safely performed at NSQIP-affiliated hospitals by both non-pediatric and pediatric surgeons. Further studies are needed to determine if there are differences in specific procedure-related complications and long-term outcomes between surgeon types.

Papillary and Follicular Thyroid Cancer in children and adolescents: Current approach and future directions

An increasing number of children are diagnosed with differentiated thyroid cancer. With an excellent prognosis for the majority of pediatric patients, the goal of therapy is to optimize outcome while reducing complications. Increased knowledge of the somatic, oncogenic driver mutations provides opportunities to improve the accuracy of diagnosis, to stratify surgery, and to treat patients with morbidly invasive or refractory disease. Treatment complications can be reduced by referral to regional, high-volume pediatric thyroid centers.

Pediatric thyroid cancer: Risk factors for central lymph node metastasis in patients with cN0 papillary carcinoma

INTRODUCTION

Prophylactic central neck node dissection (CND) for pediatric patients with papillary thyroid cancer (PTC) is still controversial. We aimed to identify the incidence and the predictive parameters of the central lymph node metastasis (CLN) in pediatric patients with cN0 PTC.

METHODS

This retrospective study had included 32 pediatric patients with cN0 PTC who underwent total thyroidectomy and prophylactic CND from 2015 to 2019.

RESULTS

The proportion of CLN metastasis was 75.0%. Univariate logistic regression demonstrated that CLN metastasis was associated with age (≤15 years; p = 0.028), tumour size > 1 cm (p = 0.008), multifocality (p = 0.028) and external extension (p = 0.041) Multivariate logistic regression revealed that age (≤15 years), multifocality, tumour size (>1 cm) and external extension were independent risk factors of CLN metastasis in pediatric patients.

CONCLUSIONS

In summary, central lymph node metastasis occurred in 75% of cN0 pediatric patient and were more common in larger tumour size (>1 cm), multifocal tumours, extrathyroidal extension, and younger age.

FASpecT/CT, A New SPECT/CT Acquisition With Higher Sensitivity and Efficiency in Radioiodine Thyroid Cancer Imaging

PURPOSE

This article demonstrates the use of a new SPECT/CT acquisition protocol in patients with differentiated thyroid cancer (DTC).

METHODS

SPECT/CT scans (FASpecT/CT) with fewer angle acquisitions were retrospectively reviewed in 30 DTC patients treated with radioiodine at University Hospital, San Antonio, Tex, from July 2017 to March 2019. This FASpecT/CT of 12 versus 60 to 64 sampled views for convention SPECT was made possible by iterative reconstruction.

RESULTS

The FASpecT/CT protocol was judged to increase lesion detection in patients with low count rates. Furthermore, in patients with higher count rates, this technique reduced the acquisition time. FASpecT/CT patient images are shown as case examples in 4 of the 30 patients reviewed.

CONCLUSIONS

This FASpecT/CT acquisition in radioiodine-treated DTC offers the potential of higher sensitivity for metastatic lymph node detection in low count rates and a significant decrease in imaging time in high count rates. These advantages make SPECT/CT imaging more acceptable for patients who have difficulty with longer imaging times, to include the pediatric population.

Noninvasive Follicular Thyroid Neoplasm With Papillary-Like Nuclear Features in Children: An Institutional Experience and Literature Review

BACKGROUND

Papillary thyroid carcinoma (PTC) in children has a distinctive set of clinicopathologic features and molecular signature compared to their adult counterparts. The recent recommendation to reclassify encapsulated follicular variant of papillary thyroid carcinoma (EFVPTC) without invasion as noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) is based on evidence derived almost exclusively from studies in adults. Clinicopathologic studies restricted to pediatric NIFTP are limited.

METHODS

We retrospectively analyzed all pediatric PTC and NIFTP diagnosed and treated in our institution from 1999 to 2016 (n = 31).

RESULTS

Using recently published consensus diagnostic criteria, we identified 3 NIFTP and 2 infiltrative follicular variants of papillary thyroid carcinoma (FVPTC) among 31 cases. Two of the NIFTP cases were initially diagnosed as EFVPTC. All 3 patients with NIFTP had unifocal tumors of lower American Joint Committee on Cancer (AJCC) classification (T2 or lower) and were free of lymph node or distant metastasis. Total (n = 1) or completion (n = 2) thyroidectomy was performed in all cases, and only 1 NIFTP patient received subsequent radioablative therapy. No residual or recurrent disease has been observed during follow-up (15-138 months) in patients with NIFTP.

CONCLUSIONS

Our experience with NIFTP in children is similar to outcomes reported in adult studies, suggesting that pediatric NIFTP behave indolently as evidenced by the absence of local recurrence in our cohort.

Recurrence and Complications in Pediatric and Adolescent Papillary Thyroid Cancer in a High-Volume Practice

BACKGROUND

Treatment approaches for pediatric papillary thyroid cancer (PTC) are historically extrapolated from adult experience. However, pediatric PTC demonstrates a greater propensity for lymph node involvement, early metastases, and recurrence, highlighting the need for pediatric-specific treatment paradigms.

MATERIALS AND METHODS

A retrospective review included patients with PTC aged ≤21 y, with ≥18 mo of follow-up, treated between 2002 and 2015. Fisher's exact test and Cox proportional hazard were used to estimate the effect of risk factors on disease recurrence.

RESULTS

Seventy-two cases of PTC were identified with median age of 17.0 y and median follow-up of 64.1 mo. Disease recurred at a median of 24.6 mo (range 7.8-78.1) in 7 of 51 (13.7%) of patients with disease limited to the thyroid or central neck, 7 of 18 (39%) patients with lateral neck disease at presentation who underwent a compartment-based resection, and three of three patients (100%) with lateral neck disease who sought care after non-compartment-based resection. There were no deaths from disease. Univariate predictors of recurrence included tumor size >2 cm (P = 0.005), lateral neck disease (P = 0.004), lymphovascular invasion (P = 0.017), extracapsular invasion (P < 0.0001), multifocality (P = 0.03), and non-Caucasian race (P = 0.05). Multivariate analysis identified race (P = 0.05) as an independent predictor of recurrence. In patients without lateral neck disease, there was a trend toward lower recurrence in patients undergoing thyroidectomy with central neck dissection compared with thyroidectomy alone (P = 0.07).

CONCLUSIONS

Pediatric PTC is associated with excellent survival, although recurrence is common in patients with lateral node involvement. Predictors of recurrence are multifactorial and may be influenced by extent of disease, patient or tumor biology, and aggressiveness of resection.

LEVEL OF EVIDENCE

Prognosis study, level IV, retrospective case series.

Thyroid Sequelae of Pediatric Cancer Therapy

The hypothalamic-pituitary-thyroid axis is a common site of unintended, acquired disease either during or after the treatment of cancer. Children treated with external radiation therapy are at the highest risk for developing a thyroid-related late effect, but thyroid dysfunction and second primary thyroid neoplasms can also occur after treatment with radiopharmaceutical agents such as 131I-metaiodobenzylguanidine. Increasingly recognized is the development of early thyroid dysfunction as an off-target consequence of the more novel cancer therapeutics such as the tyrosine kinase inhibitors and immune checkpoint inhibitors. Thyroid sequelae resulting from irradiation may manifest only after years to decades of follow-up, and their resultant clinical symptoms may be indolent and non-specific. Therefore, lifelong monitoring of the childhood cancer survivor at risk for thyroid disease is paramount. In this comprehensive review, the myriad thyroid adverse effects resulting from pediatric cancer treatment are discussed and an overview of screening and treatment of these thyroid sequelae provided.

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.

The relationships of surgeon volume and specialty with outcomes following pediatric thyroidectomy

BACKGROUND

Previous studies of pediatric thyroidectomies suggest a volume-outcome relationship, but none have focused exclusively on pediatric surgical specialists. Our objective was to examine the effects of pediatric surgeon volume and specialty on post-thyroidectomy outcomes.

METHODS

The Pediatric Health Information System was queried for patients ≤21 years who underwent partial or total thyroidectomy between 2005 and 2016. Multivariable logistic regression with propensity score weighting was used to assess the relationships between surgeon volume or specialty and 90-day thyroidectomy-specific complications. High-volume surgeons/hospitals were defined as those in the top tertile of annual thyroidectomies.

RESULTS

The inclusion criteria were met by 3149 patients. Patients treated by higher-volume surgeons had significantly fewer complications than those treated by lower-volume surgeons (15.0% vs. 19.2%, p = 0.01). Patients with thyroid cancer also had less morbidity when treated by higher-volume surgeons compared to lower-volume surgeons (25.0% vs. 35.1%, p = 0.03), as did children with Graves' disease (19.8% vs. 29.3%, p = 0.007). Patients managed by pediatric surgeons had fewer complications than those managed by pediatric otolaryngologists across all patients (14.0% vs. 22.5%, p < 0.001) and among cancer (25.3% vs. 42.1%, p < 0.001) and Graves' patients (20.1% vs. 37.3%, p < 0.001) specifically.

CONCLUSIONS

Morbidity following pediatric thyroidectomy is associated with surgeon volume.

TYPE OF STUDY

Prognostic Study.

LEVEL OF EVIDENCE

Level II.

Trends in pediatric thyroid cancer incidence in the United States, 1998-2013

BACKGROUND

Pediatric differentiated thyroid cancer (DTC) rates have increased over time in the United States and worldwide. Improvements in imaging for the diagnosis of DTC have been hypothesized as a potential driver of these increases. This study stratifies temporal trends in pediatric DTC by stage and tumor size to assess whether rates of large, late-stage cancers, which are likely to be clinically meaningful, are increasing over time.

METHODS

Age-standardized incidence rates (ASRs) of DTC and annual percent changes (APCs) in primary DTC rates were estimated for 0- to 19-year-olds with data from 39 US cancer registries during 1998-2013.

RESULTS

During 1998-2013, 7296 cases of DTC were diagnosed (6652 papillary cases and 644 follicular cases). APCs of pediatric DTCs significantly increased by 4.43%/y [95% CI, 3.74%/y-5.13%/y], primarily because of increases in papillary histologies. Increasing trends were observed for children aged 10 to 19 years for both sexes and for non-Hispanic whites, non-Hispanic blacks, and Hispanics. Rates increased significantly over the time period for all tumor stages (APC_localized , +4.06%/y [95% CI, 2.84%/y-5.29%/y]; APC_regional , +5.68%/y [95% CI, 4.64%/y-6.73%/y]; APC_distant , +8.55%/y [95% CI, 5.03%/y-12.19%/y]) and across tumor sizes (APC_<1 cm , +9.46%/y [95% CI, 6.13%/y-12.90%/y]; APC_1-2 cm , +6.92%/y [95% CI, 4.31%/y-9.60%/y]; APC_>2 cm , +4.69%/y [95% CI, 2.75%/y-6.67%/y]).

CONCLUSIONS

Significantly increasing rates of DTC over time among 10- to 19-year-olds in the United States are unlikely to be entirely explained by increases in medical surveillance during childhood because rates of large and late-stage DTC are increasing over time. Future studies should examine environmental and other factors that may be contributing to rising DTC rates.

Treatment outcomes in pediatric differentiated thyroid carcinoma

Background Until the American Thyroid Association (ATA) guidelines on management of pediatric differentiated thyroid carcinoma (DTC) became available in 2015, all children with DTC were treated like adults. This study aims to investigate the outcome of pediatric DTC and factors predicting the response to therapy in pediatric DTC managed according to adult guidelines. Methods Clinical records of 41 children less than 18 years of age diagnosed with DTC followed from 2007 in a single center were reviewed. According to the new ATA classification for pediatric DTC, five had low-risk, 28 had intermediate-risk and eight had high-risk disease at presentation. Results There was no mortality or recurrence in this cohort of pediatric DTC patients and the cure rate was 46% during a mean follow-up of 44 months when they were managed according to adult guidelines. Neither the new ATA risk classification nor any clinicopathological character was identified which could predict the response to therapy. The new ATA guidelines would have avoided 27% of the radioiodine therapies given. Conclusions This study showed that DTC in children managed according to adult guidelines had a good cure rate. The new ATA guidelines on pediatric DTC might have drastically reduced the number of radioiodine therapies in the affected children. Long term prospective studies are needed to validate the benefits and risks of both these approaches.

Cervical Lymph Node Metastases of Papillary Thyroid Carcinoma, in the Central and Lateral Compartments, in Children and Adolescents: Predictive Factors

PROBLEM STATEMENT

The aim of our study was to identify predictive factors for lymph node metastases (LNM) in children and adolescents with papillary thyroid carcinoma (PTC) and their impact on survival.

METHODS

The authors conducted an Italian multicentric retrospective analysis on 132 pediatric patients (0-18 years old) affected by PTC between 2000 and 2014. The investigated variables were demographic characteristics of the patients, clinicopathological features of PTCs, and persistence/recurrence of disease. The female/male ratio was 3.1:1. The median age was 14.3 ± 3.5 years (range 4-18 years). Total thyroidectomy was performed in all the patients, followed by lymph node dissection in 87 patients (65.9%). Metastatic lymph node involvement was confirmed in 73 patients (55.3%): lateral compartment (LC) in 25 patients (34.2%), central compartment (CC) in 17 patients (23.3%), and both compartments in 31 patients (42.5%).

RESULTS

Multifocality (P < .00), vascular invasion (P = .04), infiltration of the thyroid capsule (P < .00), minimal extrathyroidal extension (P < .00), diffuse sclerosing variant of PTC (P = .02), and presence of LNM in the LC (P < .00) were significantly associated with LNM in CC. Infiltration of the thyroid capsule (P < .00), massive extrathyroidal extension (P = .03), distant metastases (P = .02), PTC, not otherwise specified (P < .00), and presence of LNM in the CC (P < .00) were significantly associated with LNM in LC. Age, sex and size of PTC were not correlated with the presence of cervical LNM. Moreover, presence of LNM in CC increases the risk of persistence (P < .01) and recurrence (P < .02) of PTC in children and adolescents.

CONCLUSIONS

Most predictors, unfortunately, are only identified post-operatively by histopathologic examination: Just a small part of them can be pre-operatively detected with a low-sensitivity neck ultrasonography. In PTC patients with pre-operative predictors, we suggest an accurate pre- and intra-operative evaluation of CC and/or LC to find suspicious lymph nodes. The presence of LNM in CC has an impact on disease/progression/relapse-free survival. We suggest performing RAI therapy and an accurate follow-up for pediatric patients with only post-operative predictors.

Ultrasound and the Evaluation of Pediatric Thyroid Malignancy: Current Recommendations for Diagnosis and Follow-up

Ultrasound (US) plays a critical role in the evaluation, treatment, screening, and surveillance of thyroid malignancy in pediatric patients. This review aims to summarize recent advances in this topic. Improvements in imaging technology have amplified the advantage of US and US-guided fine-needle aspiration biopsy for thyroid nodule evaluation, cancer diagnosis, and surgical planning. Ultrasound has a definitive screening role for early cancer detection in high-risk patients, including those with a history of radiation exposure from childhood treatments, environmental radiation disasters, or hereditary/familial cancer syndromes. Finally, US is a key component of lifelong surveillance for recurrence among pediatric thyroid cancer survivors.

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.

DICER1 Mutations Are Frequent in Adolescent-Onset Papillary Thyroid Carcinoma

CONTEXT

Papillary thyroid carcinoma (PTC) is a common malignancy in adolescence and is molecularly and clinically distinct from adult PTC. Mutations in the DICER1 gene are associated with thyroid abnormalities, including multinodular goiter and differentiated thyroid carcinoma.

OBJECTIVE

In this study, we sought to characterize the prevalence of DICER1 variants in pediatric PTC, specifically in tumors without conventional PTC oncogenic alterations.

PATIENTS

Patients (N = 40) who underwent partial or total thyroidectomy and who were <18 years of age at the time of surgery were selected.

DESIGN

The 40 consecutive thyroidectomy specimens (30 malignant, 10 benign) underwent genotyping for 17 PTC-associated variants, as well as full sequencing of the exons and exon-intron boundaries of DICER1.

RESULTS

Conventional alterations were found in 12 of 30 (40%) PTCs (five BRAFV600E, three RET/PTC1, four RET/PTC3). Pathogenic DICER1 variants were identified in 3 of 30 (10%) PTCs and in 2 of 10 (20%) benign nodules, all of which lacked conventional alterations and did not recur during follow-up. DICER1 alterations thus constituted 3 of 18 (16.7%) PTCs without conventional alterations. The three DICER1-mutated carcinomas each had two somatic DICER1 alterations, whereas two follicular-nodular lesions arose in those with germline DICER1 mutations and harbored characteristic second somatic RNase IIIb "hotspot" mutations.

CONCLUSIONS

DICER1 is a driver of pediatric thyroid nodules, and DICER1-mutated PTC may represent a distinct class of low-risk malignancies. Given the prevalence of variants in children, we advocate for inclusion of DICER1 sequencing and gene dosage determination in molecular analysis of pediatric thyroid specimens.

Pediatric differentiated thyroid carcinoma: trends in practice and outcomes over 40 years at a single tertiary care institution

BACKGROUND

This study aims to analyze changes in characteristics, practice and outcomes of pediatric differentiated thyroid cancer (DTC) at our tertiary care institution.

METHODS

Patients <21 years of age diagnosed between 1973 and 2013 were identified. Clinicopathological data, treatment and outcomes were obtained by a retrospective review.

RESULTS

Thirteen males and 68 females were divided into Group A (n=35, diagnosed before July 1993) and Group B (n=46, diagnosed after July 1993). Group B was more likely to undergo neck ultrasound (US) (70% vs. 23%, p<0.0001) and fine-needle aspiration (FNA) biopsy (80% vs. 26%, p<0.0001). Patients in Group B more often underwent total thyroidectomy as a definitive surgical treatment (87% vs. 69%, p=0.04). There was no difference in radioactive iodine use. Recurrence-free survival was similar.

CONCLUSIONS

Increased use of US and FNA has affected initial surgical management in the latter part of the study, possibly due to extension of adult DTC guidelines. The effects of the new pediatric DTC guidelines need further study.

Risk prediction in children and adults less than 45 years old with papillary thyroid cancer

The incidence of papillary thyroid cancer is increasing faster than any other cancer in young patients. The purpose of this review is to discuss the most recent determinants of risk of recurrence and compromised outcomes in this population. Areas covered: This review discusses the most updated data on patient age, including children and young adults, extent of disease and subsequent dynamic staging over time, molecular markers for disease aggressiveness, adequacy of surgical resection and surgeon volume, and novel therapies for advanced non-resectable disease as predictors of patient outcomes. Expert commentary: Young patients enjoy excellent outcomes, with long-term survivorship, but face higher risks of short-term complications and disease recurrence. Thoughtful evaluation of the extent of disease, tumor features associated with more aggressive behavior, the presence of locoregional or distant metastases, and an understanding of molecular changes in their tumors are important areas of consideration. High-volume surgeons should work collaboratively with endocrinologists, radiologists, and pathologists specializing in thyroid cancer to help patients achieve excellent outcomes. Emerging data challenging the status quo regarding the relative importance of patient age, tumor features, and dynamic risk-adjustment for overall prognosis of these patients will likely impact future care and staging systems.

Paediatric follicular thyroid carcinoma - indolent cancer with low prevalence of RAS mutations and absence of PAX8-PPARG fusion in a Japanese population

AIMS

Paediatric follicular thyroid carcinomas are uncommon, and their clinicopathological features and molecular profiles are still unknown. In the present study, we aimed to investigate the clinicopathological aspects of a large series of follicular thyroid carcinomas (FTCs) in paediatric patients and to analyse the point mutations in codons 12, 13 and 61 of NRAS, HRAS and KRAS genes and the rearrangements of PAX8-PPARG.

METHODS AND RESULTS

A total of 41 paediatric FTCs less than 21 years of age were enrolled into the present study. We used direct sequencing and reverse transcription-polymerase chain reaction (RT-PCR) to detect RAS mutations and PAX8-PPARG fusions, respectively. The paediatric FTCs were 6:1 in a female to male ratio, with a mean tumour size of 52.7 mm. Distant metastasis was found in one case at the time of presentation. During a median follow-up time of 69 months, two cases had lung metastasis and all patients were alive. Histologically, all cases were minimally invasive FTCs and varied in growth patterns: microfollicular (39%), follicular (14.6%), solid/trabecular (6%), oncocytic (4.9%) and mixed patterns (26.8%). The mean Ki67 index was 5.7% and it was not statistically different among the growth patterns. NRAS mutations were found in five cases (12.2%) and associated significantly with small tumour size (P = 0.014). PAX8-PPARG fusion was not detected in our series.

CONCLUSION

Paediatric FTCs are indolent in clinical course in spite of their large tumour size and have a distinct genetic background. RAS mutations and PAX8-PPARG fusions may not play major roles in the tumorigenesis of paediatric FTCs.