Childhood and adolescent thyroid carcinoma

Epidemiological and histopathological characteristics of thyroid carcinoma in a Tunisian health care center

Background

Thyroid carcinoma (TC) accounts for almost 0.5%-1% of total malignancies. Its incidence is increasing rapidly worldwide. Several studies have drawn up the epidemiological profile of TC and its clinical and pathological features. However, to date, no similar studies have been conducted in Tunisia.

Aims

To establish an epidemiological profile of TC in a Tunisian health care institute and to analyze its clinical and histopathological characteristics in our institute.

Materials and Methods

We present a retrospective study reviewing the cases of TC diagnosed in our institution in a 4-year period.

Results

We collected a sample of 192 cases of TC. It consisted of 31 males and 161 females (83.8%) with a sex-ratio M/F of 0.19. The mean age was 46.4 years. Papillary thyroid carcinoma was the most frequent histological subtype. The multifocality rate was 33.8%. The mean size of TC was 2.2 ± 1.9 cm. 60.9% of TC were staged pT1 and 20.3% had nodal involvement. Papillary thyroid microcarcinomas were noted in 37.5% of cases.

Conclusion

Our results were consistent with those of the literature. A high proportion of pT1 and pN0 tumors were noted in our series, suggesting that TC's diagnosis and management was performed at an early stage of the disease in our institution. In addition, our study enabled us to notice the impact of the Coronavirus disease 19 crisis on the management of TC in our institution. Further studies are needed to establish the epidemiological profile of TC in Tunisia and to assess its clinical and pathological features.

More aggressive biological behavior in pediatric than in adult papillary thyroid carcinoma

OBJECTIVE

Papillary thyroid carcinoma (PTC) remains a common malignancy of the endocrine system in children and adolescents. This study aimed to investigate the differences in clinical characteristics between children and adults with PTC.

METHODS

A total of 360 patients [ 308 adults (≥20 years) and 52 children and adolescents (<20 years)] with PTC who underwent thyroid surgery in our center from 2017 to 2022 were retrospectively analyzed. Statistical analysis and comparisons of the clinicopathological data and tumor characteristics between children and adults were performed.

RESULTS

Among all enrolled patients, the mean tumor diameter was 26.21 ± 12.72 mm in the pediatric group, while that in the adult group was 11.62 ± 10.21 mm, which was a significant difference (p < 0.001). Pediatric patients were more prone to central lymph node metastasis (90.38% vs. 49.35%, p<0.001), lateral lymph node metastasis (78.85% vs. 45.7%, p<0.001), capsular invasion (90.38% vs. 63.96%, p<0.001) and extrathyroidal extension (61.54% vs. 15.26%, p＜0.001) than adult patients. However, the pediatric group had a lower BRAFV600E mutation rate (54.76% vs. 87.7%, p < 0.001) and lower incidence of Hashimoto's thyroiditis (15.38% vs. 30.84%, p = 0.023) than the adult group. There were no significant differences in clinicopathological factors, such as sex, multifocality and hypothyroidism.

CONCLUSIONS

Pediatric patients were more likely to present with advanced disease at diagnosis, including larger tumor volume, more lymph node metastasis, more extensive local invasion, and lower rates of BRAF mutation and concomitant Hashimoto's thyroiditis. Therefore, appropriate surgical management and comprehensive treatment decisions are needed for pediatric patients with PTC.

Radioactive Iodine-Refractory Pulmonary Metastases of Papillary Thyroid Cancer in Children, Adolescents, and Young Adults

CONTEXT

Few studies have explored radioactive iodine-refractory (RAIR) disease in children, adolescents, and young adults with papillary thyroid cancer (CAYA-PTC).

OBJECTIVE

This study systematically investigated the clinicopathologic characteristics and prognosis of CAYA-PTC with RAIR disease.

METHODS

Sixty-five patients with PTC aged ≤20 years were enrolled in this study, and all patients were confirmed to have pulmonary metastases. Clinicopathologic profiles were compared between the radioactive iodine-avid (RAIA) and RAIR groups. Univariate and multivariate regression analyses were performed to identify risk factors for RAIR status and progressive disease (PD). Gene alterations were detected in 17 patients.

RESULTS

Overall, 20 patients were included in the RAIR group, accounting for 30.8% (20/65) of all patients. No significant difference in pathologic characteristics was observed between patients aged <15 years and patients aged 15-20 years, but younger patients were more likely to develop RAIR disease (hazard ratio [HR] 3.500, 95% CI 1.134-10.803, P = .023). RET fusions were the most common genetic alterations in CAYA-PTC, but an association with RAIR disease was not detected (P = .210). RAIR disease (HR 10.008, 95% CI 2.427-41.268, P = .001) was identified as an independent predictor of PD. The Kaplan-Meier curve revealed a lower progression-free survival (PFS) and disease-specific survival (DSS) rate in the RAIR group than in the RAIA group (P < .001 and P = .039). Likewise, RAIR disease was a risk factor for unfavorable PFS in patients aged <15 years (P < .001).

CONCLUSION

RAIR disease occurs in one-third of CAYA-PTC with pulmonary metastases. Younger patients (aged < 15 years) are more susceptible to RAIR status, which leads to unfavorable PFS and DSS.

Comparison of the Robotic Bilateral Axillo-Breast Approach and Conventional Open Thyroidectomy in Pediatric Patients: A Retrospective Cohort Study

Background: Operations for pediatric thyroid nodules are more complicated, and usually lead to longer scars, which may impair life quality in the long term. Bilateral axillo-breast approach robotic thyroidectomy (BABA RT) may provide a better alternative to conventional open thyroidectomy (COT) for pediatric thyroid nodules. Our study aimed at comparing the surgical and oncological outcomes of BABA RT and COT in pediatric patients. Methods: The data of 49 pediatric patients who consecutively underwent BABA RT or COT (20:29) between July 1998 and November 2021 in our center were retrospectively analyzed, including demographics, surgery extent, surgical outcomes, pathological characteristics, and oncological outcomes. Results: All BABA RT procedures were completed successfully without conversion to open operation. The BABA RT group consisted of 5 benign and 15 malignant cases, while the COT group consisted of 19 benign and 10 malignant cases. The operation time, drain removal time, and number of lymph nodes harvested by central lymph node dissection or lateral lymph node dissection were equivalent in the BABA RT and COT groups. Notably, the postoperative hospital stay of the BABA RT group was shorter than that of the COT group (8.5 [interquartile ranges (IQRs): 3] vs. 11 [IQR: 8] days, p = 0.008). The aesthetic score of the BABA RT group was much higher than that of the COT group (9 [IQR: 1] vs. 6 [IQR: 1], p < 0.001). There was no significant difference between the BABA RT and COT groups in hypoparathyroidism rate (transient, 5 vs. 4; permanent, 1 vs. 0). There was one case of chyle leakage in the COT group and no other complications in any group, such as recurrent laryngeal nerve injury. With a median follow-up of 101 (IQR: 189) months, one case of local relapse and one case of pulmonary metastasis in the COT group were documented. Conclusion: In the hands of experienced surgeons, robotic BABA thyroidectomy can be a safe and effective option for both benign and malignant thyroid nodules in children, including those with lymph node metastasis. Robotic BABA thyroidectomy can offer a better and faster postoperative course and a much better cosmetic result, which is crucial for pediatric thyroid patients.

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.

The Role of American Thyroid Association Pediatric Thyroid Cancer Risk Stratification and BRAFV600E Mutation in Predicting the Response to Treatment in Papillary Thyroid Cancer Patients ≤18 Years Old

OBJECTIVE

This study aimed to evaluate the role of risk stratification by the American Thyroid Association (ATA) pediatric thyroid cancer risk levels and BRAF^V600E mutation to predict the response to treatment in papillary thyroid cancer (PTC) patients ≤18 years old.

METHODS

Clinical outcomes during a median period of 6 (2-21.8) years were assessed in 70 patients, according to ATA pediatric risk stratification, BRAF^V600E mutation status, and dynamic risk stratification (DRS) at final follow-up.

RESULTS

Of 70 patients, 44 (63%), 14 (20%), and 12 (17%) were classified initially as low-, intermediate-, and high-risk, respectively. BRAF^V600E mutation analysis data was available in 55 (78.6%) patients, of whom 18 (32.7%) had the BRAF^V600E mutation. According to the final DRS, 61 (87%), two (3%), six (9%), and one (1%) patients were classified as an excellent, incomplete biochemical, incomplete structural, and indeterminate response, respectively. All ATA low-risk patients showed excellent response to treatment, whereas the rate of excellent response was 65.4% in intermediate- and high-risk levels (p<0.001). The rates of excellent response in BRAF^V600E positive and negative patients were 83% and 92%, respectively (p=0.339). The rate of locoregional recurrence was significantly higher in BRAF^V600E positive vs negative patients (33.3% vs 2.7% respectively, p=0.001).

CONCLUSION

ATA pediatric risk stratification is effective in predicting response to treatment in PTC patients ≤18 years old. The presence of BRAF^V600E mutation was highly predictive for recurrence but had no significant impact on the rate of excellent response to treatment at final follow-up.

Epidemiology and treatment of head and neck malignancies in the AYA generation

The Adolescent and Young Adult (AYA) population refers to the population of young adults and adolescents in the 15-39 years age group. This population subgroup experiences various important life events. Head and neck malignancies are rare tumors, in general, but they are extremely rare in the AYA population. When analyzed by the primary site of the tumors, thyroid gland, soft tissue, and nasopharyngeal malignancies are the most commonly encountered head and neck malignancies in the AYA generation. The most common histopathologic subtypes are carcinomas (thyroid carcinoma, nasopharyngeal carcinoma) and rhabdomyosarcoma. Therefore, in this review, the author discusses these three diseases in the AYA population in detail. Especially, patients with parameningeal rhabdomyosarcoma are at a high risk of dysfunction and facial deformity. Infertility problems may also occur as long-term sequelae of chemotherapy in this population. Radiation therapy might be associated with considerable morbidity. Complications such as cataract, xerostomia, hearing loss, neck fibrosis, and trismus are also common. Head and neck surgeons and medical oncologists should choose the optimal treatment taking into account the curability of the tumors relative to the long-term adverse events of treatment use. Finally, little evidence has been accumulated on head and neck malignancies in the AYA population, and it is urgently necessary to build a high level of evidence for the future.

Age, American Thyroid Association Risk Group, and Response to Therapy Are Prognostic Factors in Children With Differentiated Thyroid Cancer

CONTEXT

Against the background of increasing incidence, pediatric differentiated thyroid carcinoma (DTC) frequently presents with advanced disease and high recurrence rates while prognosis remains excellent.

BACKGROUND

We investigated the use of a pediatric classification and an adult response to therapy risk stratification for pediatric DTC patients and their implications for adaptation of treatment and follow-up.

METHODS

Data from patients aged <18 years with a diagnosis of primary DTC, registered with the German Pediatric Oncology Hematology-Malignant Endocrine Tumor registry since 1995, were analyzed. For risk prediction, patients were retrospectively assigned to the American Thyroid Association (ATA) risk groups and evaluated for response to therapy.

RESULTS

By October 2019, 354 patients with DTC had been reported (median age at diagnosis 13.7 years, range 3.6-17.9) with lymph node and distant metastases in 74.3% and 24.5%. Mean follow-up was 4.1 years (range 0-20.6). Ten-year overall and event-free survival (EFS) rates were 98.9% and 78.1%. EFS was impaired for patients with lymph node and distant metastases (P < .001), positive postoperative thyroglobulin (P = .006), incomplete resection (P = .002), sequential surgeries to achieve total thyroidectomy (P = .042), invasion of capsule (P < .001) and lymph vessels (P = .005), infiltration of surrounding soft tissues (P < .001), tumor multifocality (P < .001), ATA intermediate- and high-risk group (P < .001), and age <10 years (P < .001). Multivariate analysis revealed age <10 years at diagnosis, ATA high-risk level, and poor response to therapy as significant negative prognostic factors for EFS.

CONCLUSION

Age, ATA risk group, and response to therapy emerged as significant prognostic factors for EFS in pediatric patients with DTC, requiring risk-adapted individualized therapy and follow-up.

Recombinant human thyroid-stimulating hormone versus thyroid hormone withdrawal preparation for radioiodine ablation in differentiated thyroid cancer in children, adolescents and young adults

OBJECTIVE

Recombinant human TSH (rhTSH) is commonly used to prepare patients for postoperative radioiodine (I-131) ablation after surgery for differentiated thyroid cancer (DTC). In adults, rhTSH is associated with equivalent oncologic efficacy in comparison to thyroid hormone withdrawal (THW), but its use has not been well studied in children. We aimed to measure time to disease progression after rhTSH stimulation vs. THW in paediatric patients under the age of 21 with DTC following total thyroidectomy.

DESIGN

Retrospective cohort study (March 2001-July 2018).

PATIENTS

Sixteen children and adolescents (75% female, median age, 17.4 years) who received rhTSH were compared to 29 historical controls (72% female, median age, 18.5 years) prepared with THW, followed for a median of 2.4 years (range, 0.5-14).

MEASUREMENTS

Stimulated serum TSH concentrations prior to I-131 ablation and time to disease progression, as determined by a component outcome variable encompassing both structural and biochemical disease persistence/recurrence.

RESULTS

No differences were observed in tumour characteristics and I-131 dose (median 2.3 [1.8-2.90] mCi/kg rhTSH) between groups. Patients who received rhTSH achieved a similar median stimulated TSH level (163 [127-184] mU/L), compared to those who underwent THW (136 [94.5-197] mU/L; p = .20). Both groups exhibited similar time to progression (p = .13) and disease persistence/recurrence rates (rhTSH 31% vs. THW 59%, p = .14).

CONCLUSION

In this cohort of children and adolescents with DTC, we observed similar time to disease progression among those who received rhTSH or underwent THW prior to postoperative I-131 ablation.

Accuracy of the Lymph Node Yield in Surgery for Papillary Thyroid Cancer in Children

INTRODUCTION

Our aim was to determine the accuracy of lymph node yield (LNY) for pediatric patients undergoing thyroidectomy with concurrent lymph nodes harvest for clinically node-negative (cN0) papillary thyroid cancer (PTC).

METHODS

Patients aged ≤ 18 years with cN0 PTC undergoing thyroidectomy were reviewed in the NCDB, 1998-2016. Demographic and clinical characteristics of patients with ≥ 1 LNY were compared to those without. A truncated beta-binomial distribution estimated the number of lymph nodes needed to detect pathologic nodal positivity, and LNY was calibrated for 90% sensitivity in nodal staging and stratified across clinical tumor size staging (T).

RESULTS

1,948 children with cN0 PTC underwent surgical resection; median age was 17 years; 83.2% were female; 47.6% were T1, 25.3% T2, 9.3% T3. 1,272 (65.3%) of these patients had lymph nodes resected, or ≥ 1 LNY. The median LNY was 5 nodes (interquartile range 2-12); 45.9% of patients had ≥ 1 metastatic lymph nodes. In the overall ≥ 1 LNY cohort, 12 nodes (CI 9-19) were needed to predict nodal positivity with > 90% sensitivity. Based on clinical T-stage, detecting a metastatic lymph node with > 90% sensitivity required a LNY of 14 for T1; 8 for T2; 6 for T3.

CONCLUSION

This is the first study estimating the necessary LNY for determining nodal positivity in children with cN0 PTC. The high LNY required in small T1 tumors is likely infeasible and should not be pursued. Accuracy increases with lower LNYs for higher T-stages. Our findings can help guide prognosis and treatment for pediatric patients with PTC.

Molecular Alterations in Relation to Histopathological Characteristics in a Large Series of Pediatric Papillary Thyroid Carcinoma from a Single Institution

Papillary thyroid carcinoma (PTC) presents distinct clinico-pathological and molecular differences in children compared with adult patients. Whether the presence of rearrangements or point mutations is associated with aggressive PTC clinical presentation is still controversial. In this study, PTCs diagnosed in patients aged less than 18 years were retrospectively searched from the institutional archive and tumor tissue was tested for point mutations in BRAF and RAS genes and for rearrangements in RET, NTRK1, NTRK3, ALK, PPARG, BRAF and THADA. A total of 163 PTCs were analyzed. Point mutations were found in 83 (51%) and gene fusions in 48 cases (30%). The most frequent alteration was the BRAFV600E mutation (36.8%), followed by NTRK3 fusion (11%), NRAS mutation (10.4%) and RET fusion (10.4%). Fusion-driven PTCs showed more frequently infiltrative growth, larger tumors, extrathyroidal extension and N1b disease. PTCs showing solid growth pattern were significantly enriched in gene fusions. This is one of the largest cohorts of pediatric PTCs. Fusion-driven tumors most frequently show aggressive pathological features; the search for rearrangements, especially in tumors with solid areas, could improve the characterization of pediatric PTCs and offer possible therapeutic options.

Clinical Assessment of Pediatric Patients with Differentiated Thyroid Carcinoma: A 30-Year Experience at a Single Institution

Background

Thyroidectomy is the typical treatment for pediatric thyroid carcinoma; total thyroidectomy is commonly performed. We aimed to report our experience at a single tertiary institution and to evaluate the risk factors for recurrence, especially based on surgical extent, in pediatric patients with differentiated thyroid carcinoma (DTC).

Methods

A data of 94 pediatric patients who underwent thyroid surgery for DTC from January 1982 to December 2012 at Yonsei University Hospital (Seoul, Korea) were reviewed. The clinicopathologic features and surgical outcomes were retrospectively analyzed through complete chart reviews.

Results

The mean age was 16.6 ± 3.0 (range, 5–19) years. Fourteen patients had recurrence. Tumor size >2 cm (hazard ratio [HR], 14.241; p = 0.011) and positive lymph nodes (HR, 1.056; p = 0.039) were significant risk factors for disease-free survival (DFS) in multivariate analysis. In Kaplan–Meier analysis, a statistically significant difference was noted in the DFS according to tumor size 2 cm (p < 0.001). However, the DFS was not significantly different between the bilateral total thyroidectomy (BTT) and less than BTT groups (p = 0.215).

Conclusions

BTT remains the treatment of choice in pediatric patients with DTC. Lobectomy may be considered for patients with limited disease, including those with tumor size <2 cm, no suspicious lymph nodes, intrathyroidal lesion, and no multifocal disease.

Radiofrequency Ablation for Cervical Metastatic Lymph Nodes in Children and Adolescents With Papillary Thyroid Carcinoma: A Preliminary Study

OBJECTIVE

To evaluate the safety and efficacy of radiofrequency ablation (RFA) for metastatic lymph nodes (LNs) in children and adolescents with papillary Thyroid Carcinoma (PTC).

MATERIALS AND METHODS

From December 2014 to March 2018, 10 metastatic LNs(mean volume 0.30 ± 0.38 ml, range 0.06-1.23ml) in 5 children and adolescents (3 females, 2 males; mean age 15.60 ± 2.97 years, range 12-19 years) with PTC treated by RFA were evaluated in this study. The mean number of surgical procedures performed before RFA was 1.2 (range 1-2) and the mean number of treated metastatic LNs per patient was 2 (rang 1-3). RFA was performed with an 18-gauge bipolar RF applicator under local anesthesia. Follow-up consisted of US and serum thyroglobulin (Tg) level at 1, 3, 6, 12 months and every 12 months thereafter.

RESULTS

All the patients were well tolerant to RFA procedure and no procedure-related complications occurred. During a mean follow-up time of 52.00 ± 21.44 months, the initial volume of LNs was 0.30 ± 0.38 ml, which significantly decreased to 0.01 ± 0.03 ml (P = 0.005) with a mean VRR of 99.28 ± 2.27%. A total of 9 metastatic LNs (90.00%) completely disappeared. After RFA, 2 patients developed newly metastases. One patient had additional RFA. The other one with multiple LN metastases underwent total thyroidectomy with central neck dissection.

CONCLUSION

As a less invasive and effective technique, RFA may provide another alternative to the existing therapeutic modalities for cervical metastatic LNs in children and adolescents with PTC.

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

CONTEXT

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

OBJECTIVE

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

DESIGN, SETTING, AND PARTICIPANTS

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

MAIN OUTCOME MEASURE

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

RESULTS

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

CONCLUSION

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

Pediatric differentiated thyroid carcinoma: An update from the APSA Cancer Committee

BACKGROUND

Differentiated thyroid carcinomas (DTCs) are rare in young children but represent almost 10% of all malignancies diagnosed in older adolescents.

METHODS

This article reviews the recent literature describing surgical therapeutic approaches to pediatric DTC, associated complications, and long-term recurrence and survival outcomes.

RESULTS

Similar to adult thyroid cancers, pediatric DTCs are more common in females and are associated with thyroid nodules, family history of thyroid cancer, radiation exposure, iodine deficiency, autoimmune thyroid disease, and genetic syndromes. Management of thyroid cancers in children involves ultrasound imaging, fine needle aspiration, and surgical resection with treatment decisions based on clinical and radiological features, cytology and risk assessment.

CONCLUSIONS

Total thyroidectomy and compartment based resection of clinically involved lymph node basins form the cornerstone of treatment of DTC. There is an evolving literature regarding the use of molecular genetics to inform treatment strategies and the use of targeted therapies to treat iodine refractory and surgically unresectable progressive disease.

TYPE OF STUDY

Summary review.

LEVEL OF EVIDENCE

This is a review article of previously published Level 1-5 articles that includes expert opinion (Level 5).

Papillary Thyroid Carcinoma in Children: Clinicopathological Profile and Outcomes of Management

BACKGROUND

We aim to analyze the clinicopathological profile and outcomes of management for children with papillary thyroid carcinoma (PTC).

METHODS

Relevant clinical data of children ≤ 18 years of age managed for PTC between January 2006 and July 2018 as well as details of their follow-up till December 2019 were retrospectively collected and analyzed.

RESULTS

There were 82 children with PTC that were managed during the study period. At presentation, 39 (47.6%) had cervical lymphadenopathy, while 9 (11%) had systemic metastasis. Majority of patients 39 (47.6%) underwent total thyroidectomy with a selective neck dissection, while total thyroidectomy alone was performed in 26 (31.7%). Following surgery, hypocalcemia was seen in 39 (47.6%): 28 (34.1%) were temporary, while 11 (13.4%) were permanent. Twenty-eight (34%) developed persistent disease after surgery and ¹³¹I therapy. Significant risk factors for persistence and metastatic disease were metastatic cervical lymph node at presentation (p = 0.002) and tumor size (p = 0.014), respectively. The mean duration of follow-up was 60.3 (range 12-150) months with a mean overall disease-free survival of 60 months (95% CI 57.11, 77.95).

CONCLUSION

Children with papillary thyroid cancers present with aggressive disease, 47.6% with cervical nodal metastasis and 11% with distant metastasis in this cohort. The rate of post-thyroidectomy hypocalcemia in this study is substantial, and efforts to reduce it are actively being pursued. The presence of metastatic cervical lymph node at presentation (p = 0.002) and tumor size (p = 0.014) were the only significant risk factors for persistent and metastatic disease, respectively, in this study.

Predominant DICER1 Pathogenic Variants in Pediatric Follicular Thyroid Carcinomas

Background: Pediatric thyroid cancer has characteristics that are distinct from adulthood thyroid cancer. Due to its very low prevalence, little is known about the genetic characteristics of pediatric follicular thyroid cancer (FTC). Methods: We investigated genetic alterations in tumor tissues from 15 patients aged <20 years (median: 14.3 years; range: 2.4 - 19.0 years) using multifaceted approaches. Whole-exome sequencing, targeted next-generation sequencing using a cancer gene panel, and Sanger sequencing of the major exons of the H/K/N-RAS and DICER1 genes and the promoter region of the TERT gene were performed. Normal tissues or blood of patients with DICER1- or PTEN-positive tumors was also evaluated to determine whether the variant is germ line. Results: The median tumor size was 3.1 cm (range: 0.6 - 6.4 cm). Four patients exhibited angioinvasion and one extensive capsular invasion; none showed evidence of disease over a median of 8.1 years. Eight patients (53.3%) had DICER1 variants, including four with DICER1 syndrome (three patients were <10 years of age). One patient had a germ line PTEN frameshift variant with the diagnosis of PTEN hamartoma tumor syndrome. One patient had a PAX8/PPARγ rearrangement, and two patients had no genetic driver alteration other than multiple loss of heterozygosity with or without copy number alterations in their tumors. No RAS or TERT variants were found. Nodular hyperplasia and follicular adenoma (FA) coexisted in DICER1 variant-positive FTCs more frequently than variant-negative FTCs (p = 0.026). All DICER1 variant-positive FTCs had a somatic missense variant at metal binding sites (six at codon p.E1813 and two at codon p.D1709) within the RNase IIIb domain; seven had other missense, nonsense, or frameshift variants in the DICER1 gene. Six coexisting FAs of two patients with DICER1 syndrome (three of each) had additional somatic variants at metal binding sites within the RNase IIIb domain (codon p.E1705, p.D1709, p.D1810, or p.E1813), different from each other and from the indexed FTC tumor. Conclusions: Pediatric FTCs have distinct genomic alterations and pathogenesis compared with adults, particularly those characterized by DICER1 variants. The DICER1 variant should be considered in pediatric FTCs, especially in cases <10 years of age. In all DICER1 variant-positive FTCs and FAs, recurrent hotspot variants were found at metal binding sites within the RNase IIIb domain, suggesting they impact tumorigenesis.

Management of pediatric differentiated thyroid cancer: An overview for the pediatric oncologist

Differentiated thyroid cancer (DTC) is the most common childhood thyroid malignancy. The standard of care for pediatric DTC is total thyroidectomy followed by radioactive iodine (RAI) treatment when indicated. Molecular changes and potential therapeutic targets have been recently described in pediatric thyroid cancer. Pediatric oncologists are increasingly involved in the evaluation of thyroid nodules in childhood cancer survivors and in the management of advanced thyroid cancer. In 2015, the American Thyroid Association published management guidelines for children with DTC. We provide an overview of the current standard of care and highlight available targeted therapies for progressive or RAI refractory DTC.

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.

Quantitative Assessment of Thyroid Glands in Healthy Children With Shear Wave Elastography

The local shear wave speed (in meters per second) and Young modulus (in kilopascals) of normal thyroid glands were defined in healthy children to determine reference values.This prospective study assessed 107 pediatric cases (age interval, 3-17 years; mean, 9.37 ± 3.68 years), including 52 boys and 55 girls. The study group included children without thyroid gland disease (autoimmune, infectious, or neoplastic). Data about the sex, age, weight, height, and body mass index (BMI) of the subjects were recorded for all subjects. Elasticity values were measured from 3 different sites in both thyroid lobes and averaged.Median values for elasticity and shear wave velocity measured in bilateral thyroid lobes were 6.38 ± 1.97 kPa (range, 3.00-12.5 kPa) and 1.45 ± 0.21 m/s (range, 1.03-2.04 m/s) on the right and 8.81 ± 3.00 kPa (range, 3.80-22.6 kPa) and 1.69 ± 0.26 m/s (range, 1.13-2.68 m/s) on the left. There was no significant difference between the elasticity values for the right and left thyroid lobes between boys and girls. There was a positive correlation between right thyroid lobe mean elasticity (in kilopascals) and shear wave velocity (in meters per second) values with age, BMI, and right thyroid lobe volume in the whole group. No significant correlation was found between left thyroid lobe mean elasticity (in kilopascals) and shear wave velocity (in meters per second) values with age, BMI, and left thyroid lobe volume in the study population.This study determined mean elasticity and shear wave velocity values for thyroid gland in healthy children. This information can be used as a baseline for the investigation of thyroid diseases.

Risk factors of post-surgery complications in children with thyroid cancer

INTRODUCTION

Thyroid cancer in children is a hot topic because of the large clinical heterogeneity and the risk of severe complications. We aimed to study 1. The frequency, 2. Etiology, and 3. Risk factors of post-surgery complications of thyroid cancer.

MATERIAL AND METHODS

A retrospective analysis including risk factors for post-surgery complications of patients treated for thyroid malignancies in years 2006-2018 was performed.

RESULTS

Over a period of 12 years 22 patients with thyroid malignancy (68% female; 12.6 ± 4.0 years of age, median follow-up 6 years) were identified. Histologically, 12 (55%) patients had papillary carcinoma. Six patients (27.3%) had multiple endocrine neoplasia type 2 (MEN2) syndrome, 3 (13.7%) patients had medullary carcinoma and 1 patient had follicular carcinoma. Neck lymph node metastases were diagnosed in 8 (36.4%), distant metastases in 6 (27.3%), and both locations were involved in 4 (18.2%) patients. Six (27.3%) children had surgical complications: 1 child had unilateral vocal cord paralysis and transient hypoparathyroidism and 5 had transient hypoparathyroidism. The higher risk of surgery complications in forward stepwise logistic regression was associated in with distant metastases (R2 = 0.584, OR 52.63, p = 0.010).

CONCLUSIONS

Postoperative complications were significantly associated with presence of distant metastases. Favorable results were observed in with children with MEN2 syndrome.

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.

Multifocal papillary thyroid cancer in children and adolescents: 12-year experience in a single center

Background

Thyroid cancer is the most common endocrine malignant disease in children and adolescents. There is a trend of more conservative strategies including lobectomy and less radioactive iodine therapy (RAI) in multifocal papillary thyroid cancer (PTC) for its good survival outcome. The aim of our study was to define long-time outcome of a large cohort of multifocal PTC patients less than 20 years old treated at our institution.

Methods

Data were collected from 276 cases who were initially diagnosis of PTC under the age of 20 from January 2006 to December 2015 at Fudan University Shanghai Cancer Center. All patients received total/near total thyroidectomy or lobectomy. Therapeutic central-compartment (level VI) and lateral neck lymph node dissection performed for patients with clinically involved neck nodes. RAI therapy used in selected patients. No patients received chemotherapy or kinase inhibitor therapy. Thyroid-stimulating hormone (TSH) suppression therapy was performed in all patients for at least 5 years.

Results

Ninety among 276 were multifocal PTC patients and included in this study. The median follow-up time was 54.28 months, ranging from 6.10 to 141.27 months. Fifteen patients had tumor recurrence during the follow-up. On Kaplan-Meier survival curves, lymphovascular invasion and extrathyroidal extension was associated with a decline in recurrence-free survival. However, there was no difference in recurrence-free survival curves in patients no matter which treatment they had received, either lobectomy or total thyroidectomy, RAI or not.

Conclusions

More conservative strategies including lobectomy and less RAI in multifocal PTC among children and adolescents are safe and effective.

Differentiated Thyroid Cancer in the Pediatric/Adolescent Population: Evolution of Treatment

Differentiated thyroid cancer (DTC) is the most common cancer in adolescents and young adults. In 2015, the American Thyroid Association published guidelines for management of pediatric DTC. We report our institutional experience and highlight changing practices and new opportunities. A retrospective analysis of all patients diagnosed with DTC from 2001 to 2016 was performed. Among 59 eligible patients, 31 (53%), 15 (25%), and 13 (22%) had low-risk, intermediate-risk, and high-risk disease, respectively. Half (15/31) of low-risk and all intermediate-risk/high-risk patients received radioactive iodine (I-131) ablation. For low-risk patients, average I-131 dose decreased from 80 to 42.05 mCi, and the percentage of patients who received I-131 decreased over time. Eleven of 16 patients with tumor genomic data were found to have somatic targetable (n=6) or germline (n=5) mutations. Persistent/recurrent disease was only present in high-risk (n=8) and intermediate-risk (n=1) patients. Two patients with iodine-refractory disease received trametinib to enhance radioiodine uptake. All patients were alive at follow-up (median, 5 y; range, 1 to 15 y). Coincident with the recent American Thyroid Association guidelines, the use of I-131 in low-risk patients has decreased over time in our practice. Tumor sequencing and cancer genetic evaluation may help redefine opportunities for treatment of high-risk patients and family counseling.

Lung Metastasis in Pediatric Thyroid Cancer: Radiological Pattern, Molecular Genetics, Response to Therapy, and Outcome

CONTEXT

Lung metastases are common in pediatric thyroid cancer (TC). We present an analysis of a series of lung metastases in pediatric TC.

PATIENTS AND METHODS

Data from 20 patients (16 females, 4 males; median age, 14.5 years; range 10 to 18 years) were analyzed. The tumors included differentiated TC in 19 patients and poorly differentiated TC in 1 patient.

RESULTS

Lung metastasis presented with three distinct radiological patterns: lung uptake on diagnostic radioactive iodine whole body scan (DxWBS) only in 3 patients (15%); lung uptake on DxWBS and CT scan as micrometastases (≤1 cm) in 16 patients (80%); and lung uptake on DxWBS and CT scan as macrometastases (>1 cm) in 1 patient (5%). Iodine-131 therapies were administered to all patients (median, three; range one to eight) with a median cumulative administered activity of 317.5 mCi (range, 109 to 682 mCi). None of the patients achieved a complete response but the biochemical response was substantial. During a median follow-up period of 8.2 years (range, 0.75 to 16.3 years), 1 patient (5%) died, 1 patient (5%) had a biochemically incomplete response, 2 patients (10%) had an indeterminate response, 1 patient (5%) had progressive structural disease, and 14 patients (70%) had stable structural disease. Mutational testing of 10 of 20 tumors revealed only two PIK3CA mutations in a single tumor.

CONCLUSIONS

Lung metastases are common in pediatric TC and present most frequently with bilateral radioiodine-avid micrometastases. Known single point mutations in adult TC are rare in pediatric TC. The biochemical response to iodine-131 can be substantial but resolution of structural abnormalities is rare.

Lymph node ratio predicts recurrence in pediatric papillary thyroid cancer

BACKGROUND

Regional lymph node (LN) metastasis at the time of presentation plays a significant role in predicting recurrence in patients with papillary thyroid cancer (PTC). Multiple studies in the adult population have demonstrated that the lymph node ratio (LNR) in both the central and lateral neck can improve the accuracy of recurrence prediction, but this ratio has not been studied in the pediatric population. In this study, we sought to investigate the LNR in the central and lateral compartments as a prognostic predictor for recurrence in pediatric patients with PTC.

METHODS

A retrospective analysis of pediatric patients (≤21 years old) at a single institution between 2002 and 2014 who underwent total thyroidectomy with prophylactic central neck dissection (TTpCND) with at least 3 sampled nodes or total thyroidectomy with unilateral modified radical neck dissection (TTMRND) with at least 10 sampled nodes, and on whom at least 24 months of follow up data were available was performed. The LNR was defined as the ratio of metastatic LNs to total number of investigated LNs. Recurrence after TTpCND and TTMRND was examined separately as a function of LNR, using the value of 0.45 as a cutoff.

RESULTS

Forty-eight patients met inclusion criteria. Thirty-two underwent TTpCND, and sixteen underwent TTMRND. Median age at time of operation was 17 years (range 6-20), and median duration of follow-up was 53.5 months (range 24-183). In the TTpCND, LNR ranged from 0 to 1.0. There were two recurrences among the eight patients (25%) undergoing TTpCND in patients with LNRs >0.45 and a single recurrence among the 24 patients (4.2%) undergoing TTpCND with an LNR ≤0.45. In the TTMRND, LNR ranged from 0.1 to 1.0. There were 3 recurrences in 12 patients with LNR ≤0.45 (30.8%%) and 4 recurrences in 4 patients with LNR >0.45 (100%) (p = 0.03).

CONCLUSIONS

Although limited by small sample size, LNR may be a useful predictor to stratify the likelihood of recurrence in pediatric patients undergoing TTpCND or TTMRND for pathologic N1a or N1b PTC.

TYPE OF STUDY

Prognosis study / retrospective case series.

LEVEL OF EVIDENCE

Level IV.

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.

Management outcomes of pediatric and adolescent papillary thyroid cancers with a brief review of literature

Background

Papillary carcinoma of thyroid (PTC) is a rare disease in children and adolescents and contributes to about 1.5%-3% of all pediatric malignancies. To date, no randomized trial has ever been performed in the pediatric population and management of these patients has been extrapolated from adult practice.

Materials and Methods

Retrospective analysis of the patients treated for PTC in the age <21 years, between the years 1998-2013 at a tertiary cancer center from India.

Results

Sixty-seven patients were treated in the above said period with a male:female ratio of 1:1.6 and a median age of 18 years. Fifty-two (77.6%) patients clinically presented as a thyroid swelling with or without nodal swelling while 13 (19.4%) presented with isolated nodal swelling. Surgery was performed in 30 patients at a nononcological hospital and was subsequently referred to our center; more than half of them needed a completion surgery at our center. Pathologically, multifocal tumors were found in close to a quarter of the patients. Among the pathological variants, classical, follicular, and tall cell variants comprised 65.7%, 28.4%, and 5.9% of the cases, respectively. Nodal positivity was noted 71.6% of the cases of which 14.5% were N1a disease and the vast majority (85.5%) harboring N1b disease. The median follow-up period of the study cohort was 104 months during which there were 3 local, 6 nodal, and 2 systemic recurrences. The 5- and 10-year disease-free survival were found to be 85.9% and 81.4%, respectively. Univariate and multivariate analysis has shown no significant clinical and pathological feature defining the disease outcomes except for the T-stage. Logistic regression revealed extrathyroidal invasion and the age ≤ 15 years correlated with nodal positivity.

Conclusion

Being a rare malignancy, pediatric and adolescent PTCs tend to behave differently from adult PTC with a seemingly aggressive clinical presentation; however, they are associated with excellent survival outcomes.

Response to Lenvatinib in Children with Papillary Thyroid Carcinoma

BACKGROUND

Papillary thyroid carcinoma (PTC) is the most common thyroid malignancy in children and adolescents. Infrequently, children with PTC may present with or develop disease not amenable to surgery or radioactive iodine (RAI), and systemic therapy may be an option. Lenvatinib is an oral tyrosine kinase inhibitor that is approved by the Food and Drug Administration for the treatment of adults with locally recurrent or metastatic, progressive, RAI-refractory well-differentiated thyroid carcinoma. The effect of lenvatinib in children with PTC has not been reported.

PATIENT FINDINGS

Three children with metastatic PTC not amenable or refractory to RAI who responded to lenvatinib are reported. All of them developed respiratory distress requiring oxygen caused by extensive bilateral metastatic pulmonary disease. The first patient is a 14-year-old female who was initially treated with sorafenib for extensive PTC not amenable to upfront surgery or RAI. She had progressive pulmonary disease after five months, and was subsequently treated with oral lenvatinib (14 mg/m²/day). She was weaned to room air after eight weeks. The second patient is a 15-year-old male who was treated with lenvatinib (14 mg/m²/day) for iodine non-avid diffuse pulmonary disease after initial total thyroidectomy and cervical lymph node dissection. He was weaned off oxygen in six weeks. The third patient is a five-year-old male who was treated with lenvatinib (14 mg/m²/day) for pulmonary disease progression 24 months after treatment with total thyroidectomy, cervical lymph node dissection, and RAI treatment. He was weaned off oxygen one day after starting lenvatinib. Two of the patients required dose adjustments secondary to proteinuria. Otherwise, all patients tolerated lenvatinib well. The first two patients remained clinically stable on lenvatinib 23 months and 11 months after initiation of therapy, respectively, and the third patient transitioned to a tumor-specific targeted therapy after one month.

SUMMARY

Three pediatric patients are reported with metastatic PTC not amenable or refractory to RAI who achieved a response on lenvatinib.

CONCLUSION

Lenvatinib therapy is well tolerated and demonstrated clinical activity in children with advanced PTC. Lenvatinib should be considered in children with PTC that is refractory or not amenable to conventional management.

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.

A Rare Case of Heterozygous Gain of Function Thyrotropin Receptor Mutation Associated with Development of Thyroid Follicular Carcinoma

Activating mutations in thyrotropin receptor (TSHR) have been previously described in the context of nonautoimmune hyperthyroidism and thyroid adenomas. We describe, for the first time, a mutation in TSHR contributing to follicular thyroid carcinoma (FTC) in an adolescent. A 12-year-old girl presented with a right-sided neck swelling, increasing in size over the previous four weeks. Clinical examination revealed a firm, nontender thyroid nodule. Ultrasound scan of the thyroid showed a heterogeneous highly vascular mass. Thyroid function tests showed suppressed TSH [<0.03mU/L], normal FT4 [10.1pmol/L, 9-19], and raised FT3 [9.1pmol/L, 3.6-6.4]. Thyroid [TPO and TRAB] antibodies were negative. A right hemithyroidectomy was performed and the histology of the sample revealed follicular carcinoma with mild to moderate nuclear pleomorphism and evidence of capsular and vascular invasion (pT1b). Sanger sequencing of DNA extracted from the tumour tissue revealed a missense somatic mutation (c.1703T>C, p.Ile568Thr) in TSHR. Papillary thyroid carcinomas constitute the most common thyroid malignancy in childhood, while FTC is rare. FTC due to TSHR mutation suggests an underlying, yet to be explored, molecular pathway leading to the development of malignancy. The case is also unique in that the clinical presentation of FTC as a toxic thyroid nodule has not been previously reported in children.

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.

Thyroid cancer in adolescents and young adults

In adolescents and young adults, thyroid cancer accounts for 13% of all invasive neoplasms, being three times more frequent in females, but overdiagnosis and overtreatment are common. There are two therapeutic approaches, one radical and no longer preferred in all instances, and the other conservative. Permanent complications of surgery and metabolic irradiation can affect quality of life and carry an economic burden. The overall survival rate approaches 100% for patients with differentiated thyroid cancer regardless of the extent of treatment. Medullary thyroid carcinoma is a very different entity, occurring most frequently in the context of hereditary tumor susceptibility syndromes.

Disease Burden and Outcome in Children and Young Adults With Concurrent Graves Disease and Differentiated Thyroid Carcinoma

CONTEXT

Adults with differentiated thyroid cancer (DTC) and Graves disease (GD) demonstrate a greater reported disease burden and aggressive DTC behavior. To date, no studies have examined the impact and long-term outcome of concurrent GD and DTC (GD-DTC) in children and young adults.

DESIGN

Single institution, retrospective longitudinal cohort study between 1997 and 2016.

PARTICIPANTS

One hundred thirty-nine children and young adults with DTC, diagnosed at median age 15 (range, 5 to 23) years, compared with 12 patients with GD-DTC, median age 18 (range, 12 to 20) years.

MAJOR OUTCOME MEASURES

Patient demographics, preoperative imaging, fine needle aspiration (FNA) cytology, operative and pathological reports, laboratory studies, treatment, and subsequent 2-year outcomes.

RESULTS

Compared with DTC, patients with GD-DTC were significantly older at the time of DTC diagnosis (P < 0.01). Patients with GD-DTC were more likely to exhibit microcarcinoma (P < 0.01), and 2 of 12 (17%) demonstrated tall cell variant papillary thyroid cancer (PTC) vs 2 of 139 (2%) in patients who had DTC alone (P = 0.03). Although patients with DTC showed greater lymphovascular invasion (60% vs 25%; P = 0.03), no group differences were noted in extrathyroidal extension, regional lymph node, and distant or lung metastasis. There were no group differences in the 2-year outcome for remission, persistent disease, or recurrence.

CONCLUSIONS

Concurrent DTC in pediatric patients with GD is not associated with a greater disease burden at presentation and shows no significant difference in 2-year outcomes compared with DTC alone. Similar to adults, microcarcinoma and tall cell variant PTC is prevalent in pediatric patients with GD-DTC. For patients who have GD-DTC with an identified nodule on ultrasound imaging prior to definitive therapy, FNA biopsy is recommended to guide definitive treatment.

Clinical characteristics and treatment of thyroid cancer in children and adolescents: a retrospective analysis of 83 patients

OBJECTIVE

To study the clinical characteristics, treatment, and prognosis of thyroid cancer in children and adolescents.

METHODS

We performed a retrospective analysis of clinical data from 83 cases of thyroid cancer in children and adolescents from January 1990 to December 2010. We compared extra-thyroid extension, lymph node metastasis, distant metastasis, and prognosis between pediatric patients ≤12 years of age (27 cases) and those >12 years of age (56 cases). All the patients agreed to undergo thyroidectomy and endocrine therapy, and the consent was obtained from parents or guardians.

RESULTS

Histopathology included papillary carcinoma in 67 cases, papillary carcinoma with partial follicular growth pattern in 1 case, papillary carcinoma with squamous metaplasia in 4 cases, follicular carcinoma in 7 cases, medullary carcinoma in 3 cases, and poorly differentiated carcinoma in 1 case. The total lymph node metastasis rate was 78.31%. Patients ≤12 years of age showed a higher rate of lymph node metastasis than the older group (92.59% vs. 71.43%, P=0.028). The incidence rate in females in the older group was higher than that in the younger group (80.36% vs. 59.26%, P=0.041). There were no significant differences in extra-thyroid extension, distant metastasis, survival rate, or recurrent disease between the two groups.

CONCLUSIONS

The lymph node metastasis of thyroid cancer is higher in patients ≤12 years of age than in those >12 years of age; the incidence rate is higher in females than in males. Childhood thyroid cancer has a good prognosis, surgery being the most effective treatment. Choosing a reasonable surgery method and comprehensive postoperative treatment can achieve a cure and satisfactory survival rate.

Differentiated thyroid carcinoma presentation may be more aggressive in children and adolescents than in young adults

Background

The available studies concerning the influence of age on the phenotypical expression of differentiated thyroid carcinoma (DTC) have hitherto compared DTC presentation either between pre-pubertal and pubertal children or between pediatric patients and aged adults; aim of this study was to ascertain for the first time whether presentation of DTC may significantly vary according to age, even within a peculiar study population covering only young patients aged less than 30 years.

Methods

The main clinical, biochemical and pathologic data at DTC diagnosis were retrospectively recorded in 2 selected cohorts including, respectively, 18 children and adolescents aged less than 18 years (Group A) or 45 young adults aged between 20 and 29.8 years (Group B).

Results

The statistical distribution of DTC cases in the different age ranges was found to progressively increase with increasing age; furthermore, the patients of Group A exhibited at diagnosis a more severe clinical involvement and a higher rate of extra-regional metastases; finally, also the association with both autoimmune thyroid diseases (AITDs) and a biochemical hypothyroid pattern was more common in Group A patients.

Conclusions

In a study population younger than 30 years: a) the risk of developing DTC increases with age, achieving its zenith during the 3rd decade of life; b) clinical presentation is more severe in children and adolescents younger than 18 years than in the patients aged between 20 and 30; c) in the cohort of children and adolescents DTC is more often associated with AITDs, which might play some role in conditioning the more aggressive phenotypical presentation of DTC in this patient group.

Hashimoto's Disease and Thyroid Cancer in Children: Are They Associated?

Hashimoto's thyroiditis (HT) is the most common cause of thyroid disease in children and adolescents. Along with significant modifications of thyroid function, HT in pediatric age can be accompanied by relevant thyroid structural alterations. Over time, benign thyroid nodules, carcinoma and, rarely, primary non-Hodgkin lymphoma can develop. However, the relationships between HT and neoplasms are poorly defined. The main aim of this paper is to discuss what is presently known regarding the coexistence of HT and thyroid tumors. Moreover, we attempt to define the pathogenesis of cancer development in children with HT. Literature analysis showed that despite its rarity and relatively promising prognosis, thyroid cancer is associated with HT. Although not all reasons for the coexistence of these diseases are clearly defined, children with HT should be considered at higher risk for thyroid cancer development. Strict correlations between high levels of serum TSH and anti-thyroid antibodies with cancer must be remembered. The same is true for the presence of nodules, especially if multiple nodules are present and ultrasonography and thyroid fine needle aspiration cytology should be promptly used in uncertain cases.

Lessons from Fukushima: Latest Findings of Thyroid Cancer After the Fukushima Nuclear Power Plant Accident

The increase in risk for late-onset thyroid cancer due to radiation exposure is a potential health effect after a nuclear power plant accident mainly due to the release of radioiodine in fallout. The risk is particularly elevated in those exposed during infancy and adolescence. To estimate the possibility and extent of thyroid cancer occurrence after exposure, it is of utmost importance to collect and analyze epidemiological information providing the basis for evaluation of radiation risk, and to consider radiobiology and molecular genetics. In this regard, the dose-response of cancer risk, temporal changes in the rates of thyroid cancer, its histopathological types and subtypes, and frequency of underlying genetic abnormalities are important. At present, however, it is difficult or impossible to distinguish radiation-induced thyroid cancer from spontaneous/sporadic thyroid cancer because molecular radiation signatures, biomarkers of radiation exposure, or genetic factors specific to radiation-induced cancer have not yet been identified. The large-scale ultrasound screening in Fukushima Prefecture of Japan demonstrated a high detection rate of thyroid cancer in young individuals, revealing 116 and 71 cases in the first and second rounds, respectively, among the same cohort of approximately 300,000 subjects. These findings raised concerns among residents and the public that it might be due to putative exposure to radiation from the accident at Fukushima Daiichi Nuclear Power Plant. This review summarizes evaluations by international organizations and reviews scientific publications by the authors and others on childhood thyroid cancer, especially those relevant to radiation, including basic studies on molecular mechanisms of thyroid carcinogenesis. Clinical details are also provided on surgical cases in Fukushima Prefecture, and the effect of thyroid ultrasound screening is discussed. Correct understanding of issues relating to radiation and the thyroid are essential for interpretation of thyroid cancer in Fukushima.

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.

Predictors of nodal metastasis in pediatric differentiated thyroid cancer

BACKGROUND/PURPOSE

There are limited data identifying risk factors for nodal metastasis in children with differentiated thyroid cancer.

METHODS

The 1998-2011 Surveillance, Epidemiology, and End Results Program database was queried for patients ≤18years of age diagnosed with differentiated thyroid cancer who underwent nodal examination. Patients were grouped by absence or presence of nodal metastasis. Multivariable logistic regression methods were used to identify independent risk factors for nodal metastasis.

RESULTS

In total, 1075 children met study criteria: 734 (68%) had nodal metastases, while 341 (32%) did not. After adjustment, risk factors for nodal metastasis included larger tumor size (1.1-2cm: odds ratio [OR] 2.02, 95% confidence interval [CI] 1.22-3.34, p=0.006; 2.1-4cm: OR 3.37, 95% CI 2.03-5.60, p<0.001; > 4cm: OR 3.39, 95% CI 1.69-6.81, p=0.001), extrathyroidal extension (OR 7.28, 95% CI 4.07-13.01, p<0.001), and multifocal disease (OR 1.94, 95% CI 1.33-2.84, p=0.001).

CONCLUSIONS

Increasing tumor size, extrathyroidal extension, and multifocal disease are independent factors associated with nodal metastases in pediatric differentiated thyroid cancer. If these risk factors are present, children with differentiated thyroid cancer should undergo careful preoperative evaluation for evidence of lateral cervical lymph node metastases, and the central compartment should be evaluated intraoperatively, with consideration of central lymphadenectomy.

LEVEL OF EVIDENCE

Level III.

Association of patient age with high-risk pathologic features in papillary thyroid cancer

BACKGROUND

Certain patient demographics and histopathologic features are risk factors for papillary thyroid cancer (PTC) recurrence after initial treatment. Our objective was to determine whether very young age is associated with aggressive pathologic features in patients with PTC.

MATERIALS AND METHODS

A retrospective analysis was performed for PTC patients who underwent surgical treatment at the University of Michigan between 2006 and 2012. Patients with known distant metastases were excluded. Demographics, high-risk pathologic features (capsular or vascular invasion, extrathyroidal extension, lymph node metastases, and extranodal extension), and disease recurrence were analyzed.

RESULTS

632 PTC patients were included in the analysis. Median age was 49 y (range 10-87). Tumors in patients aged <25 y had higher rates of extranodal extension (P = 0.002) compared with patients aged 25-44 y. Patients aged <25 y had more vascular invasion (P < 0.001) and lymph node metastasis (P = 0.001) than tumors in patients aged between 45-75 y. Patients aged >75 y had higher rates of vascular invasion (P < 0.001) and extrathyroidal extension (P = 0.001) compared with patients aged 45-75 y and more extrathyroidal extension (P < 0.001) than patients aged 25-44 y. There were no differences in tumor characteristics between the <25 and >75 age groups.

CONCLUSIONS

PTC patients aged <25 y of age or older than 75 y exhibit higher rates of aggressive histopathologic features compared to PTC patients aged between 25-75 y.

Thyroid Cancer in Children: Management and Outcome Experience of a Referral Center

OBJECTIVE: To shed light on the discrepancy between the advanced stage at presentation and high recurrence rate of well-differentiated thyroid cancer in children and the overall good survival.

DESIGN AND METHODS: The files of 75 children with well-differentiated thyroid cancer treated from 1954 to 2001 in a major tertiary-care hospital were reviewed for disease course, management, and outcome.

RESULTS: Sixty patients (80%) had positive neck metastases with involvement of central compartment lymph nodes in all, lateral neck nodes in 36, and distant metastases in 4. Sixty-seven patients underwent total thyroidectomy with adjuvant radioiodine treatment and 8 underwent hemithyroidectomy; all had concomitant neck treatment. The rate of local (5%) and neck (9%) recurrence was similar to the total rate reported in adults. Total thyroidectomy led to a significantly lower recurrence rate (7.5%) than hemithyroidectomy (38%; P < 0.005). Type of neck dissection did not affect recurrence or appearance of distant metastases. All deaths (n = 2) were due to distant metastases, whereas 30% of adult deaths are due to local or neck disease.

CONCLUSIONS: The treatment of choice for well-differentiated thyroid cancer in young patients is total thyroidectomy. Neither regional disease at presentation nor recurrences affect survival.

PRE-ABLATION THYROGLOBULIN AND THYROGLOBULIN TO THYROID-STIMULATING HORMONE RATIO MAY BE ASSOCIATED WITH PULMONARY METASTASES IN CHILDREN WITH DIFFERENTIATED THYROID CANCER

OBJECTIVE

Pediatric differentiated thyroid cancer (DTC) frequently presents with extensive disease. We studied the value of pre-ablation thyroglobulin (Tg) and Tg normalized to thyroid-stimulating hormone (TSH) levels in predicting distant metastases in pediatric patients with DTC.

METHODS

This is a retrospective cohort study of patients <21 years old who underwent thyroidectomy followed by ¹³¹I ablation for DTC at 3 university hospitals over 20 years. Tg levels and the Tg/TSH ratio following surgery but prior to ¹³¹I ablation were assessed. The presence of distant metastatic disease was determined from the postablation whole-body scan.

RESULTS

We studied 44 patients with a mean age of 15.2 years (range 7 to 21 years) and mean tumor size of 2.8 cm. Eight patients had distant metastases and had a higher mean pre-ablation Tg value compared to patients without distant metastases (1,037 μg/L versus 93.5 μg/L, P<.01). The pre-ablation Tg/TSH ratio was also associated with the presence of distant metastases: 12.5 ± 18.8 μg/mU in patients with distant metastases versus 0.7 ± 1.8 μg/mU in patients without (P<.01). A nomogram to predict distant metastases yielded areas under the receiver operating characteristic curve of 0.85 for Tg and 0.83 for Tg/TSH ratio.

CONCLUSION

After initial thyroidectomy, elevated preablation Tg and Tg/TSH ratio are associated with distant metastatic disease in pediatric DTC. This may inform the decision to ablate with ¹³¹I, as well as the dosage.

ABBREVIATIONS

ATA = American Thyroid Association CI = confidence interval DTC = differentiated thyroid cancer OR = odds ratio ROC = receiver operating characteristic Tg = thyroglobulin.

Interpretation of thyroid glands in a group of healthy children: real-time ultrasonography elastography study

BACKGROUND

This study aimed to determine the strain index (SI) of normal thyroid parenchyma in a group of healthy children, using ultrasound elastography (USE).

METHODS

The participants consisted of 54 healthy children. The USE of the normal thyroid parenchyma was performed by using the Hitachi Hi VisionPreirus model ultrasonography (US) device. By following sinusoidal waves at the base of the screen, regular and slight compressions and decompressions were made by the transducer. After the regular sinusoidal waves were acquired, standard region of interest (ROI) circles were used to measure the SI values of the thyroid glands by placing one ROI on a superficial part of the normal thyroid gland parenchyma and the other on the adjacent soft tissue at the same depth (within 10-mm proximity). Three measurements were obtained for each (right and left) thyroid gland, and the mean value was used for statistics.

RESULTS

The mean SI value of normal thyroid glands was 0.54±0.38 for the whole group. There was no statistically significant difference between girls and boys on the basis of age, weight, height, BMI (body mass index), and thyroid SI values (p=0.15, p=0.18, p=0.12, p=0.31, and p=0.96, respectively). No correlation was found between thyroid gland SI values and each of the following variables: age (r=0.22, p=0.15), gender (r=0.007, p=0.96), and BMI (r=0.26, p=0.09).

CONCLUSIONS

The study determined the normal elasticity values of thyroid glands in healthy children. Such information can serve as a baseline from which thyroid diseases can be examined.

Thyroid Cancer in Pediatrics

Well differentiated thyroid cancer (DTC) in children is characterized by a high rate of response to treatment and low disease-specific mortality. Treatment of children with DTC has evolved toward a greater reliance on evaluation and monitoring with serial serum thyroglobulin measurements and ultrasound examinations. Radioiodine therapy is recommended for thyroid remnant ablation in high-risk patients, treatment of demonstrated radioiodine-avid local-regional disease not amenable to surgical resection, or distant radioiodine-avid metastatic disease. Sufficient time should be given for benefits of radioiodine therapy to be realized, with follow-up monitoring. Re-treatment with radioiodine can be deferred until progression of significant disease manifests.

Thyroid carcinoma in children, adolescents and adults, both spontaneous and after childhood radiation exposure

Thyroid carcinoma is the most common second malignancy for childhood cancer survivors. Radiation exposure is linked to risk. Thyroid nodules in children have a high risk for malignancy, whether spontaneous or after radiation. Due to the extremely limited available paediatric data, we sought to review a series of patients with thyroid carcinoma, seen over 25 years. Forty-six patients were identified. Thirty-nine (84.8 %) had papillary thyroid carcinoma, five (10.9 %) follicular carcinoma and 2 (4.3 %) medullary thyroid carcinoma (MEN2B). Thirty-three (71.7 %) had childhood radiation exposure (17 females) with thyroid malignancy occurring 6-37 years later. The smallest nodule size found on surveillance to have thyroid malignancy was 4 mm. Thyroid cancer in patients 16 years and under was seen in 22 patients (47.8 %). All had total thyroidectomy, with initial central node clearance from 2005. Diagnostic rTSH stimulated I(123) scan was followed by ablative I(131) if any uptake was seen. Sixteen (32.6 %) had metastases. Twenty-four (52.2 %) had I(131), four requiring multiple courses. Forty-two remain alive and well.

CONCLUSION

Ultrasound screening is required for early diagnosis as small nodule size is not predictive of benign histology or absence of metastases. Central node clearance provides better outcome. Despite metastatic disease at presentation for some, prognosis is favourable.

WHAT IS KNOWN

• Incidence of thyroid cancer has been increasing and radiation exposure in childhood cancer survivors is clearly linked to risk. • Published guidelines in many places can only provide very low level evidence due to extremely limited available paediatric data. What is New: • Paper provides good evidence to confirm existing views with the largest cohort of thyroid cancer reported to date in the paediatric age group in Australia, and the largest cohort in Australia where there have been specific high risks of radiation exposure. The only other reported larger studies have come from the Children's Oncology Group and Childhood Cancer Survivor Study [24]. • Using diagnostic rTSH stimulated I(123) scan 6 weeks after surgery helps to determine if radioactive iodine ablation is necessary and limits unnecessary bone marrow exposure for young patients in whom future leukaemia is of greater concern.