Clinical features associated with metastasis and recurrence of differentiated thyroid cancer in children, adolescents and young adults

Diagnostic accuracy of the McGill thyroid nodule score in paediatric patients

INTRODUCTION

Thyroid cancer is the most common paediatric endocrine cancer; accurate diagnosis and prompt management of paediatric thyroid nodules is critical. The McGill Thyroid Nodule Score (MTNS), based upon clinical, ultrasound (US) and cytology criteria, has recently been modified and studied in a pilot paediatric group with good results. We aim to describe the diagnostic accuracy of the paediatric modified MTNS (PMTNS) in a large paediatric cohort.

METHODS

We utilized an established retrospective cohort between 1996 and 2015 of 99 patients ≤21 years old with 131 thyroid nodules. Two experienced paediatric radiologists, blinded to pathology and radiology reports, reviewed US features. We abstracted cytology, histology and laboratory results, assigning each nodule a PMTNS. PMTNS performance was compared to FNA and histology.

RESULTS

Approximately 33% of nodules were malignant. The cohort was predominantly adolescent (mean age 15.4 ± 3.8 years). The average PMTNS for malignant and benign nodules, based on final histology, was 12.7 ± 4.3 and 1.7 ± 2.9, respectively. A PMTNS ≥8 resulted in a 93.2% sensitivity and 93.1% specificity for detecting malignancy, while a PMTNS ≥9 resulted in a 90.9% sensitivity and 96.6% specificity. However, Bethesda cytology category ≥4 independently had a 97.7% sensitivity and 94.0% specificity for detecting malignancy. The PMTNS had diminishing diagnostic accuracy in younger children compared with older children.

CONCLUSION

Paediatric modified McGill Thyroid Nodule Score predicts malignancy, perhaps due to the score's emphasis on cytology results; however, the score is less accurate in younger patients. While cytology results remain reliable, further work is needed to develop a non-invasive scoring system to predict malignancy in children.

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.

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.

Pulmonary metastases in children and adolescents with papillary thyroid cancer in China: prognostic factors and outcomes from treatment with 131I

PURPOSE

Papillary thyroid carcinoma (PTC) with pulmonary metastases is rare in children and adolescents. Unlike adults, limited data are available on children with this disease. Thus, this study evaluated the therapeutic efficacy and prognostic factors of individuals less than 21 years of age with pulmonary metastases from PTC.

METHODS

Seventy-six children and adolescents with pulmonary metastases from PTC treated with ¹³¹I were retrospectively analyzed. Therapeutic efficacy was evaluated by changes in serum thyroglobulin (Tg) and chest computed tomography (CT). Factors predictive of progression-free survival and overall survival were measured by the Kaplan-Meier method.

RESULTS

Among the 76 patients included in this study, 22.4% (17 of 76) were less than 15 years old and 65.8% (50 of 76) were female. Under the evaluation of stimulated serum Tg levels, RAI treatment were effective in 55.9% (38 of 68), stable in 26.5% (18 of 68) and ineffectvie in 17.6% (12 of 68) of patients. Changes on anatomical imaging suggested complete response (CR), partial response (PR), stable disease (SD) and progressive disease (PD) in 8.5, 62.0, 15.5, and 14.1% of individuals, respectively. Univariate analysis showed that size and tumor doubling time of pulmonary metastases were independent factors affecting therapeutic efficacy. Extra-thyroidal extension, tumor diameter of pulmonary metastases and tumor doubling time were significant independent factors regarding progression-free survival rates, while only tumor doubling time and tumor diameter were significant risk factors associated with overall survival rate.

CONCLUSIONS

Radioactive iodine therapy is an effective treatment for children and adolescents with pulmonary metastases from PTC. Extra-thyroid extension was associated with disease progression while did not show significant influence on overall survival. Tumor doubling time and tumor diameter were the main factors influencing both progression-free survival and overall survival.

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

Purpose

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

Methods

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

Results

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

Conclusion

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

Differentiated thyroid cancer in children: Heterogeneity of predictive risk factors

OBJECTIVE

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

STUDY DESIGN

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

RESULTS

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

CONCLUSIONS

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

Clinicopathological Risk Factors for Distant Metastasis in Differentiated Thyroid Carcinoma: A Meta-analysis

INTRODUCTION

Distant metastasis (DM) is not a frequent event in differentiated thyroid carcinoma (DTC) but has an adverse impact on mortality of patients with DTC. In the current study, we aimed to conduct a comprehensive systematic review and meta-analysis to investigate the risk factors for DM in DTCs and for each histological subtype.

METHODS

Five electronic databases were searched from inception to December 2016 for relevant articles. Pooled odd ratios and 95% confidence interval were calculated using random-effect model.

RESULTS

Thirty-four articles with 73,219 patients were included for meta-analyses. In DTCs, male gender, age ≥45 years, tumor size ≥4 cm, multifocality, vascular invasion (VI), extrathyroidal extension (ETE), lymph node metastasis (LNM), and lateral LNM were demonstrated to be associated with significant risks for DM. In addition, several clinicopathological factors such as age ≥45 years, VI, ETE, and LNM were shown to be significant risk factors for DM in both PTC and FTC subgroups.

CONCLUSION

Our study demonstrated the promising value of several clinicopathological factors such as male gender, older age, VI, ETE, and LNM in predicting DM in PTCs and FTCs. Our study affirms the value of the selected clinicopathological factors for tumor risk stratification and assessment of patients' prognosis.

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.

Optimizing treatment for children and adolescents with papillary thyroid carcinoma in post-Chernobyl exposed region: The roles of lymph node dissections in the central and lateral neck compartments

There is lack of data to predict lymph node metastases in pediatric thyroid cancer. The aims are to study (1) the factors affecting the lymph node metastases in children and adolescence with papillary thyroid carcinoma in region exposed to radiation and (2) to evaluate the predictive significance of these factors for lateral compartment lymphadenectomy. Five hundred and nine patients with papillary thyroid carcinoma underwent total thyroidectomy and lymph nodes resection (central and lateral compartments of the neck) surgery during the period of 1991-2010 in Belarus were recruited. The factors related to lymph node metastases were studied in these patients. In the patients with papillary thyroid carcinoma, increase number of cancer-positive lymph nodes in the central neck compartment were associated with a risk to develop lateral nodal disease as well as bilateral nodal disease. Futhermore, positive lateral compartment nodal metastases are associated with age and gender of the patients, tumour size, minimal extra-thyroidal extension, solid architectonic, extensive desmoplasia in carcinoma, presence of psammoma bodies, extensive involvement of the thyroid and metastatic ratio index revealed after examination of the central cervical chain lymph nodes. The presence of nodal disease, degree of lymph node involvement and the distribution of lymph node metastases significantly increase the recurrence rates of patients with papillary thyroid carcinoma. To conclude, the lymph nodes metastases in young patients with papillary thyroid carcinoma in post-Chernobyl exposed region are common and the pattern could be predicted by many clinical and pathological factors.

Comparison of differentiated thyroid carcinoma recurrence and its clinical features in children of different ages

The prevalence of differentiated thyroid carcinoma (DTC) in children is increasing. However, the clinical features and recurrence of DTC in children in different age groups, especially those less than 14 years old, are not well studied. We retrospectively investigated 73 children diagnosed with DTC in our hospital between January 1998 and July 2014. Data were reviewed for different age groups based on the age at initial diagnosis: 5-9, 10-14, or 15-19 years. The mean age of the recurrence group (10.6±4.1 years) was lower than that of the non-recurrence group (12.6±6.2 years; P=0.004). The main symptom at initial diagnosis was local invasion in the recurrence group, but was thyroid nodules in the non-recurrence group (P<0.001). The recurrence and non-recurrence groups did not differ in TNM stage or risk level. However, according to our age classification, the American Thyroid Association pediatric risk level was significantly different in three age groups (P=0.024). The DTC recurrence rate in each age group decreased as the age of the children increased (P=0.011). Thus, a high risk of recurrence and a high proportion of local invasion cases were observed in the youngest age group, suggesting that younger age is an important risk factor for DTC recurrence in children.

Dynamic Risk Stratification in Stage I Papillary Thyroid Cancer Patients Younger Than 45 Years of Age

BACKGROUND

This study validated the dynamic risk stratification (DRS) system with regard to its association with structural recurrence and risk factors associated with non-excellent responses in patients <45 years with stage I classical papillary thyroid cancer (PTC).

METHODS

This historical cohort study included 598 patients with stage I classical PTC <45 years of age treated with total thyroidectomy followed by radioactive iodine remnant ablation (n = 440), total thyroidectomy without radioactive iodine remnant ablation (n = 23), and thyroid lobectomy alone (n = 135).

RESULTS

The median follow-up period was 123 months. Structural recurrence occurred in 4.2% (n = 18/432) of the patients with an excellent response, 17.1% (18/105) of patients with an indeterminate response, 44.7% (17/38) of patients with a biochemically incomplete response, and 82.6% (19/23) of patients with a structurally incomplete response (p < 0.001) during the follow-up. The disease-free survival curves of each response showed significant differences (p < 0.001). Extensive extrathyroidal extension and extranodal extension were the independent risk factors associated with non-excellent response (p < 0.05).

CONCLUSIONS

DRS may reduce unnecessary additional treatments by reclassifying initial risk estimates of structural recurrence. Furthermore, applying the risk factors associated with non-excellent response to initial therapy may be a more useful and viable surrogate of the risk for structural recurrence in stage I PTC patients <45 years of age.

Validation of dynamic risk stratification in pediatric differentiated thyroid cancer

PURPOSE

There has been increasing interest in a risk-adopted management strategy known as dynamic risk stratification following the revised American Thyroid Association guidelines for differentiated thyroid cancer. We aimed to evaluate the usefulness of dynamic risk stratification for predicting structural disease in pediatric differentiated thyroid cancer patients.

METHODS

We retrospectively reviewed 130 pediatric differentiated thyroid cancer patients (≤19 years) who were treated between 1996 and 2015 at Samsung Medical Center. Patients were stratified according to three American Thyroid Association initial risk group (low, intermediate, or high risk) and four dynamic risk stratification group (excellent, indeterminate, biochemical incomplete, or structural incomplete).

RESULTS

Based on dynamic risk stratification strategy, structural disease was identified 3.9% in the excellent group, 9.7% in the indeterminate group, 76.9% in the biochemical incomplete group, and 100% in the structural incomplete group. The hazard ratios of the structural disease were 18.10 (P < 0.001) in the biochemical incomplete group, and 19.583 (P < 0.001) in the structural incomplete group compared to the excellent group. The prevalence of structural disease also increased as American Thyroid Association initial risk classification increased (5.9% in the low-risk group, 13.6% in the intermediate-risk group, and 45% in the high-risk group). The hazard ratios of structural disease in the high-risk group was 10.296 (P < 0.001) in compared to the low-risk group.

CONCLUSION

Dynamic risk stratification based on patient responses to initial therapy was able to effectively predict the risk of structural disease in a pediatric population, and as a follow-up strategy, may work as well in pediatric differentiated thyroid cancer patients as it does in adult differentiated thyroid cancer patients.

Prevalence and Significance of Thyroglobulin Antibodies in Pediatric Thyroid Cancer

CONTEXT

Circulating thyroglobulin antibodies (TgAb) can confound measurement of serum thyroglobulin and impair thyroid cancer surveillance. Few data exist on the significance of TgAb in pediatric thyroid cancer.

OBJECTIVE

To describe the prevalence, natural history, and clinical significance of TgAb in children with thyroid cancer.

DESIGN

Retrospective cohort study.

SETTING

Single academic pediatric center.

PATIENTS

Seventy-three consecutive children (≤18 years) with nonmedullary thyroid cancer who had serum TgAb measured within 6 months after diagnosis.

MAIN OUTCOME MEASURES

Prevalence and natural history of TgAb; association of TgAb status and resolution with patient and disease characteristics.

RESULTS

TgAb were detected in 41% of subjects (30 of 73) and were associated with lymph node metastasis (83% vs 53%, P = 0.01) but not distant metastasis. In patients with TgAb, resolution occurred in 44% (11 of 25) over a median follow-up of 3.8 years. Median time to clear TgAb was 10.7 months, and 10 of 11 patients who cleared (91%) did so within 2 years. Resolution of TgAb was associated with lower initial TgAb level (median 4.5 vs 76 normalized units, P = 0.003). TgAb positivity at diagnosis was not independently associated with persistent or recurrent disease (odds ratio 3.20, 95% confidence interval 0.95 to 10.80, P = 0.06).

CONCLUSIONS

TgAb are common at diagnosis in children with thyroid cancer but resolve in nearly half of patients within 1 to 2 years. TgAb are associated with the presence of lymph node metastasis at diagnosis, but the long-term prognostic significance remains to be determined.

McGill Thyroid Nodule Score in Differentiating Benign and Malignant Pediatric Thyroid Nodules: A Pilot Study

Objective The McGill Thyroid Nodule Score (MTNS) is a preoperative tool used to predict the risk for well-differentiated thyroid cancer given a specific nodule in adults. We evaluated the clinical utility of a modified pediatric MTNS with children and adolescents. Study Design Case series with chart review. Setting Tertiary care children's hospital. Subjects and Methods This is a retrospective chart review of 46 patients ≤18 years of age presenting with a solitary or dominant thyroid nodule treated with surgical resection between September 2008 and December 2015. The cumulative MTNS for each nodule was calculated and compared with the final pathology. Results Of 46 patients, 10 (21.7%) were diagnosed with well-differentiated thyroid cancer (80% papillary thyroid carcinoma, 10% follicular variant of papillary thyroid carcinoma, 10% follicular thyroid carcinoma). Malignant nodules were associated with a greater mean MTNS (benign, 5.72 ± 3.03; malignant, 16 ± 3.13; P < .05). The sensitivity, specificity, and positive predictive value of malignancy were 100%, 94.4%, and 83.3% for scores ≥10 and 80%, 100%, and 100% for scores ≥11, respectively. In nodules with indeterminate cytology (Bethesda III and IV), the pediatric MTNS showed good differentiation between benign and malignant disease, with mean scores of 7.95 and 12.5, respectively ( P = .006). Conclusion This pilot study suggests that a comprehensive scoring system may help assess the risk of malignancy in pediatric thyroid nodules and differentiate nodules with indeterminate cytology into higher- and lower-risk categories. Given these findings, larger, multi-institutional studies are warranted.

Pathologic Characteristics, Natural History, and Prognostic Implications of BRAFV600E Mutation in Pediatric Papillary Thyroid Carcinoma

The BRAF^V600E mutation is the most common genetic aberration in papillary thyroid cancer (PTC), found in up to 68% of PTC in adults where it is associated with aggressive features. The incidence of this mutation in pediatric PTC is less frequent, reported as 0%-20% in the past and up to 63% in one recent series. Data suggest the mutation is not associated with an aggressive course in children; however, there are limited numbers of reported case series, so the prognostic implications remain poorly understood. The aim of this retrospective study was to examine the histologic characteristics and clinical outcomes of BRAF positive pediatric PTC at a single institution. A 12-year retrospective review of all thyroidectomies performed at a tertiary medical center identified 59 pediatric cases with a surgical pathology diagnosis of PTC. Fifty patients had BRAF^V600E mutation analysis data and were selected for further study. BRAF^V600E mutations were present in 48% of cases (n = 24) and absent in 52% (n = 26). The molecular characteristics of the BRAF negative cases will further be evaluated in future studies. BRAF positive cases occurred in patients who were on average older than the BRAF negative patients. Classic histology PTC was present in both BRAF positive and negative cases; however, only cases with classic PTC histology were positive for the mutation. No patients died and BRAF mutation was not associated with an increased recurrence rate. Our study supports BRAF^V600E is more common in children than previously thought and does not portend a more aggressive clinical course.

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.

Pediatric Thyroidectomy

Objectives/Hypothesis To evaluate hospital course and associated complications among pediatric patients undergoing thyroidectomy. Study Design and Setting Retrospective database review of the Kids' Inpatient Database (2009, 2012). Methods The Kids' Inpatient Database was evaluated for thyroidectomy patients for the years 2009 and 2012. Surgical procedure, patient demographics, length of stay, hospital charges (in US dollars), and surgical complications were evaluated. Results Of an estimated 1099 nationwide partial thyroidectomies and 1654 total thyroidectomies, females accounted for 73.5% and 79.1% of patients, respectively. Children <1 year of age had significantly longer hospital courses ( P < .0001), and patients 1 to 5 years of age had a significantly greater length of stay than individuals 6 to 20 years of age (7.8 vs 2.1 days, P < .001). The most common complications overall included hypocalcemia, respiratory complications, vocal cord paresis/paralysis, postoperative infection, and bleeding. Vocal cord paralysis was noted in 1.7% of pediatric thyroidectomy patients. The presence of these complications among total thyroidectomy patients significantly increased one's length of stay and hospital charges. A neck dissection was reported in 22.9% of malignant thyroidectomy patients. Conclusion Nearly 20% of children who underwent total thyroidectomy experienced postoperative hypocalcemia, positing a need for the development of postoperative calcium replacement algorithms to minimize the sequelae of hypocalcemia. A greater incidence of respiratory and infectious complications among younger patients (<6 years) suggests a need for closer monitoring, possibly encompassing routine postoperative intensive care unit utilization, in an attempt to minimize these sequelae.

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.

Management of Differentiated Thyroid Cancer in Children: Focus on the American Thyroid Association Pediatric Guidelines

First introduced in 1946, radioactive iodine (I-131) produces short-range beta radiation with a half-life of 8 days. The physical properties of I-131 combined with the high degree of uptake in the differentiated thyroid cancers (DTCs) led to the use of I-131 as a therapeutic agent for DTC in adults. There are two indications for the potential use of I-131 therapy in pediatric thyroid disorders: nonsurgical treatment of hyperthyroidism owing to Graves' disease and the treatment of children with intermediate- and high-risk DTC. However, children are not just miniature adults. Not only are children and the pediatric thyroid gland more sensitive to radiation than adults but also the biologic behavior of DTC differs between children and adults as well. As opposed to adults, children with DTC typically present with advanced disease at diagnosis; yet, they respond rapidly to therapy and have an excellent prognosis that is significantly better than that in adult counterparts with advanced disease. Unfortunately, there are also higher rates of local and distant disease recurrence in children with DTC compared with adults, mandating lifelong surveillance. Further, children have a longer life expectancy during which the adverse effects of I-131 therapy may become manifest. Recognizing the differences between adults and children with DTC, the American Thyroid Association commissioned a task force of experts who developed and recently published a guideline to address the unique issues related to the management of thyroid nodules and DTC in children. This article reviews the epidemiology, diagnosis, staging, treatment, therapy-related effects, and suggestions for surveillance in children with DTC, focusing not only on the differences between adults and children with this disease but also on the latest recommendations from the inaugural pediatric management guidelines of the American Thyroid Association.

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.

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.

Papillary Thyroid Carcinoma in Children and Adolescents: Long-Term Follow-Up and Clinical Characteristics

BACKGROUND

The aim of this study was to analyze the clinical features and clinical outcomes of papillary thyroid carcinoma (PTC) in the pediatric and adolescent population treated in our institution.

METHODS

The subjects were 227 PTC patients 20 years of age or under treated initially between 1979 and 2012. Their mean age at diagnosis was 18-year old (range 7-20 years). Patient characteristics and outcomes in the period before 1999 and the period after 2000 were compared. Cause-specific survival (CSS) rates and disease-free survival (DFS) rates were calculated by the Kaplan-Meier method.

RESULTS

Two patients died of their disease and 45 patients had recurrent disease (36 in lymph node, seven in a remnant thyroid, and 11 in the form of distant metastasis). The 10-, 20-, and 30-CSS rates were 99.3, 99.3, and 96.5%, respectively, and the 10-, 20-, and 30-DFS were 83.6, 70.7, and 64.0%, respectively. Gender and preoperative lymph node metastasis were identified as significant factors related to DFS in the multivariate analysis. After the year 2000, there were significantly more patients with a small primary tumor size, significantly more patients without distant metastasis at presentation and significantly more patients without extrathyroidal invasion.

CONCLUSION

The number of patients with advanced cancer has been declining in recent years. Lobectomy with prophylactic unilateral central neck dissection is considered acceptable for patients without the risk factors for recurrence.

Accuracy of thyroid nodule sonography for the detection of thyroid cancer in children: systematic review and meta-analysis

INTRODUCTION

Thyroid ultrasound (US) is a widely used tool for evaluating thyroid nodules. Various US features have been suggested as predictors of thyroid cancer in children.

OBJECTIVE

To conduct a systematic review and meta-analysis to assess the diagnostic accuracy of different thyroid US features in detecting thyroid cancer in children.

METHODS

We searched multiple online databases for cohort studies that enrolled paediatric patients with thyroid nodules (age <21 years) and evaluated the accuracy of 12 relevant ultrasound features. Diagnostic measures were pooled across studies using a random effects model.

RESULTS

The search strategy yielded 1199 citations, of which 12 studies met the predefined inclusion criteria (750 nodules). The prevalence of thyroid cancer was 27·2% (40·8% in patients with a history of radiation exposure and 23·2% in patients without a history of exposure to radiation). The most common cancer was papillary thyroid cancer (86·7%). The presence of internal calcifications and enlarged cervical lymph nodes were the US features with the highest likelihood ratio [4·46 (95% CI: 1·87-10·64) and 4·96 (95% CI: 2·01-12·24), respectively] for thyroid cancer. A cystic nodule was the feature with highest likelihood ratio for benign nodules [1·96 (95% CI: 0·87-4·43)].

CONCLUSION

Thyroid US features are not highly accurate predictors of benign or malignant aetiology of thyroid nodules in children. Internal calcification may predict malignancy, and cystic appearance may suggest benign aetiology.

Pediatric Differentiated Thyroid Carcinoma of Follicular Cell Origin: Prognostic Significance of Histologic Subtypes

BACKGROUND

Thyroid cancers are rare in the pediatric age group, and unlike in adults, few data are available regarding the clinical implication of histologic subtypes in the pediatric population. The purpose of the current study was to determine the prognostic significance of histologic subtypes of differentiated thyroid cancer (DTC) in a large series of children and adolescents followed at a single institution.

METHODS

A retrospective review was conducted of all pediatric DTC patients who were treated and followed between 1988 and 2012. Sixty-two patients (median age at diagnosis 13.8 years, median age at follow-up 18 years, 77% female) were assessed. The most common subtypes included classic papillary thyroid carcinoma (PTC; 48%), diffuse sclerosing PTC (16%), and follicular variant PTC (15%); 37% were considered "high-risk" histologies based on adult criteria.

RESULTS

In a multivariate model, only extensive extrathyroidal extension (ETE), defined as the presence of two or more microscopic foci of tumor cells ≤1 mm in size each or any foci >1 mm in size invading beyond the thyroid capsule into perithyroid soft tissue or organs, was significantly associated with extent of disease at presentation. At last follow-up, 76% of subjects had no evidence of disease, 18% had persistent disease, and 5% had recurrent/progressive disease. Event-free survival was associated with extent of disease at presentation (p = 0.01), extensive ETE at diagnosis (p < 0.01), and male sex (p = 0.01), but not histologic subtype (p = 0.20).

CONCLUSIONS

Pediatric DTC carries an excellent prognosis. Extensive ETE at diagnosis was found to be an independent predictor of extent of disease at presentation, as well as event-free survival. Unlike in the adult population, "high-risk" histologic subtypes did not independently predict extent of disease at presentation or event-free survival in this pediatric population with DTC.

Thyroid-Specific Genes Expression Uncovered Age-Related Differences in Pediatric Thyroid Carcinomas

Despite a more advanced stage of disease at presentation, a better response to radioiodine (RAI) therapy and a reduced overall mortality have been reported in pediatric differentiated thyroid cancer (DTC) in comparison to adult DTC. Few studies suggested that the better response to RAI therapy in pediatric patients might be associated with an increased expression of NIS. However, a marked heterogeneity within the pediatric group has been recognized. Children (<10 years old) usually present a more aggressive disease than adolescents (≥10-18 years old). By analyzing the expression of thyroid-specific genes in 38 sporadic pediatric tumors, we show that the expression of NIS, PDS, and TSHR was lower in children than adolescents (P < 0.05). A linear regression confirmed the association between NIS expression and age. Most significantly, NIS was expressed at similar levels in DTC from children and adults, whereas PDS and TSHR expression was even lower in DTC from children, compared to adolescents and adults. Our data suggest that biological behaviors of DTC in adolescents might differ from those in children and adults. Therefore, the premise that the expression of thyroid-specific genes is higher in tumors from pediatric patients than in adults is not entirely true and might be too oversimplified.

Predictive factors for recurrence of differentiated thyroid cancer in patients under 21 years of age and a meta-analysis of the current literature

The influence of predictors for recurrence in relation to recurrence-free survival was analyzed retrospectively in differentiated thyroid cancer (DTC) patients under 21 years of age who underwent primary surgical treatment and who had a pathological diagnosis of DTC between 1983 and 2012 at Fudan University Cancer Hospital. Recurrences were retrospectively analyzed using a Cox regression model for the hazard ratio (HR) according to the clinicopathological features. A meta-analysis was performed with respect to the potential predictors for recurrence from current related studies. In the present study, there were 146 young patients aged from 7 to 20 years, with a female/male ratio of 2.65/1. Female gender was the only factor significantly associated with recurrence according to univariate (HR = 2.812, P = 0.037) and multivariate (HR = 4.107, P = 0.024) Cox regression analyses. Meta-analyses revealed that multifocality (HR = 1.91, P < 0.05) and presentation at diagnosis (HR = 1.39, P < 0.05) were highly associated with recurrence in young DTC patients. However, female gender and other factors, such as age (≤10 vs. 11-20 years), PTC (PTC vs. FTC), extrathyroidal extension, lymph node metastasis, total thyroidectomy (total vs. less than total), radioiodine therapy, and radiation history, were not associated with recurrence in young DTC patients. In conclusion, multifocality and presentation at diagnosis are strong predictive factors of recurrence in relation to recurrence-free survival. We recommend studies with larger sample sizes and longer follow-up to verify the influence of predictors for disease recurrence in young patients.

Are we really at the dawn of understanding sporadic pediatric thyroid carcinoma?

Data from the National Cancer Institute and from the literature have disclosed an increasing incidence of thyroid cancer in children, adolescents and adults. Although children and adolescents with thyroid cancer tend to present with more advanced disease than adults, their overall survival rate is excellent; however, there is no clear explanation for the differences observed in the clinicopathological outcomes in these age groups. There has been an ongoing debate regarding whether the clinicopathological differences may be due to the existence of distinct genetic alterations. Efforts have been made to identify these acquired genetic abnormalities that will determine the tumor's biological behavior and ultimately allow molecular prognostication. However, most of the studies have been performed in radiation-exposed pediatric thyroid carcinoma. Therefore, our understanding of the role of these driver mutations in sporadic pediatric differentiated thyroid cancer development is far from complete, and additionally, there is a strong need for studies in both children and adolescents. The aim of this review is to present an extensive literature review with emphasis on the molecular differences between pediatric sporadic and radiation-exposed differentiated thyroid carcinomas and adult population.

Nuclear Medicine in Thyroid Diseases in Pediatric and Adolescent Patients

Both benign and malignant diseases of the thyroid are rare in the pediatric and adolescent population, except congenital hypothyroidism. Nuclear medicine plays a major role, both in the diagnosis and therapy of thyroid pathologies. Use of radioactivity in pediatric population is strictly controlled due to possible side effects such as secondary cancers; therefore, management of pediatric patients requires detailed literature knowledge. This article aims to overview current algorithms in the management of thyroid diseases and use of radionuclide therapy in pediatric and adolescent population.

Management Guidelines for Children with Thyroid Nodules and Differentiated Thyroid Cancer

BACKGROUND

Previous guidelines for the management of thyroid nodules and cancers were geared toward adults. Compared with thyroid neoplasms in adults, however, those in the pediatric population exhibit differences in pathophysiology, clinical presentation, and long-term outcomes. Furthermore, therapy that may be recommended for an adult may not be appropriate for a child who is at low risk for death but at higher risk for long-term harm from overly aggressive treatment. For these reasons, unique guidelines for children and adolescents with thyroid tumors are needed.

METHODS

A task force commissioned by the American Thyroid Association (ATA) developed a series of clinically relevant questions pertaining to the management of children with thyroid nodules and differentiated thyroid cancer (DTC). Using an extensive literature search, primarily focused on studies that included subjects ≤18 years of age, the task force identified and reviewed relevant articles through April 2014. Recommendations were made based upon scientific evidence and expert opinion and were graded using a modified schema from the United States Preventive Services Task Force.

RESULTS

These inaugural guidelines provide recommendations for the evaluation and management of thyroid nodules in children and adolescents, including the role and interpretation of ultrasound, fine-needle aspiration cytology, and the management of benign nodules. Recommendations for the evaluation, treatment, and follow-up of children and adolescents with DTC are outlined and include preoperative staging, surgical management, postoperative staging, the role of radioactive iodine therapy, and goals for thyrotropin suppression. Management algorithms are proposed and separate recommendations for papillary and follicular thyroid cancers are provided.

CONCLUSIONS

In response to our charge as an independent task force appointed by the ATA, we developed recommendations based on scientific evidence and expert opinion for the management of thyroid nodules and DTC in children and adolescents. In our opinion, these represent the current optimal care for children and adolescents with these conditions.

Increased risk of second primary malignancy in pediatric and young adult patients treated with radioactive iodine for differentiated thyroid cancer

INTRODUCTION

The long-term sequelae of radioactive iodine (RAI) for differentiated thyroid cancer (DTC) in pediatric and young adult patients are not well-defined. Epidemiologic analyses of second primary malignancy (SPM) risk have only been performed in the adult population. Existing data are limited to case series with limited follow-up. The objective of this study was to analyze the elevated risk of SPM attributable to RAI in young patients treated for DTC.

METHODS

Population-based analysis of 3850 pediatric and young adult patients (<25 years old) undergoing treatment with surgery with/without RAI for DTC, followed in the Surveillance, Epidemiology, and End Results cancer registry (1973-2008), equating to 54,727 person-years at risk (PYR). The excess risk of SPM was calculated relative to a reference population and expressed as standardized incidence ratio (SIR) and excess absolute risk (EAR) per 10,000 PYR. Excess risk was compared in RAI-treated and non-RAI-treated patients.

RESULTS

A total of 1571 patients (40%) received RAI. The percentage of patients treated with RAI increased over time, from 4% in 1973 to 62% in 2008 (p<0.001). Among patients who received RAI, 26 SPMs were observed, and 18.3 were expected. The relative risk of SPM at any site was significantly elevated (SIR=1.42), corresponding to 4.4 excess cases per 10,000 PYR. SPM risk was not elevated in the non-RAI-treated cohort (SIR=1.01, EAR=0). Patients treated with RAI were at dramatically elevated risk for development of a salivary malignancy (SIR=34.1), corresponding to 1.7 excess cases per 10,000 PYR. The risk of leukemia in RAI-treated patients was elevated (SIR=4.0, EAR=0.9) but did not reach statistical significance. There was no elevated risk of salivary cancer or leukemia in the non-RAI-treated cohort.

CONCLUSIONS

Pediatric and young adult patients who receive RAI for DTC experience an elevated risk of SPM, mainly salivary gland cancer. These risks appear to be only slightly higher than in adult patients. Over a decade, approximately 1 in 227 RAI-treated patients will develop an SPM, and 1 in 588 RAI-treated patients will develop a salivary cancer, attributable to RAI. Because the expected survival time for young DTC patients is long, it is critical to weigh the benefits of RAI carefully against the small, but real, increase in SPM risk.

Pediatric patients with multifocal papillary thyroid cancer have higher recurrence rates than adult patients: a retrospective analysis of a large pediatric thyroid cancer cohort over 33 years

CONTEXT

Large-sample studies with long-term follow-up data are limited for pediatric patients with thyroid cancer.

OBJECTIVE

Secular changes in clinicopathological characteristics and outcomes in pediatric patients with thyroid cancer were investigated and compared with those of adults.

DESIGN AND PATIENTS

A retrospective review of 150 pediatric patients with thyroid cancer managed between 1980 and 2013 was conducted. The long-term outcomes of 124 patients followed up for 12 months or longer were evaluated. Predictors of recurrence-free survival (RFS) in pediatric patients with papillary thyroid cancer (ped-PTC group) were compared with those of 3071 adult patients.

RESULTS

The proportion of small tumors (<1 cm) increased from 9.0% before 2010 to 36.8% after 2010 (P < .001); however, neither pathological presentations such as multifocality, extrathyroidal extension (ETE), lymph node (LN) metastasis, or lung metastasis nor the RFS rate changed over time. The 5- and 10-year recurrence rates were 14.5% and 34.4% in pediatric patients, respectively. In respective analyses of the ped-PTC group and patients of all ages with papillary thyroid cancer (all ages group), the rates of ETE, LN metastasis, and lung metastasis were higher with younger age (all P for trend <.05). RFS was lower in the pediatric than the adult patients aged 20-54 years (P < .005) and was comparable with that of older patients (≥ 55 y). Only tumor multifocality and size predicted recurrence in the ped-PTC group (P < .05), whereas LN metastasis and ETE also predicted recurrence in the all-ages group (P < .01). Among patients in the all-ages group with multifocal tumors, pediatric patients had the lowest RFS (P < .05).

CONCLUSIONS

The pathological characteristics and recurrence rates of pediatric thyroid cancer have not changed over 33 years. Although younger patients present with more advanced disease, multifocality rather than age at diagnosis predicted recurrence. Recurrence was higher in pediatric than adult patients with multifocal papillary thyroid cancer.

Ultrasound characteristics of the thyroid in children and adolescents with goiter: a single center experience

INTRODUCTION

Autoimmune thyroiditis (AIT) is a common cause of goiter in children, and sonographic changes have been reported in more than one-third at presentation. The aim of this study was to evaluate the ultrasound (US) characteristics of the thyroid and the prevalence of thyroid nodules in children and adolescents presenting with goiter in the presence or absence of AIT.

METHODS

A retrospective review was conducted of the US characteristics of 154 children and adolescents aged <18 years of age with goiter from July 2008 to December 2010. US characteristics were analyzed according to each patient's age, sex, thyrotropin (TSH) levels, and thyroid peroxidase antibody titer (TPOAb). Heterogeneity and nodule prevalence were compared between antibody-positive and -negative goiter.

RESULTS

Heterogeneity was more common in TPOAb-positive (59/71, 83%) compared to TPOAb-negative goiter (24/46, 52%; p<0.001), but there was no correlation between the presence of heterogeneity and TPOAb titer within the antibody-positive group. Nodules were equally prevalent in children with (17%) and without (17.4%) TPOAb, and there was no correlation between the serum TSH level or TPOAb titer and the presence of nodules. Papillary thyroid cancer (PTC) was diagnosed in 3/71 with positive TPOAb compared to 1/46 with negative antibodies. Pseudonodules were identified in 11/71 antibody-positive and none of the antibody-negative patients. However, during follow-up, two of these were later identified as nodules and one was PTC.

CONCLUSION

The majority of children and adolescents with goiter had positive TPOAb (71/117). Sonographic heterogeneity was more common among TPOAb-positive patients. However, thyroid nodules and PTC were equally common in both groups. Only 15% of the nodules and none of the PTC were palpable. These data support the utility of thyroid US to detect unsuspected thyroid nodules and PTC in children with goiter. Prospective follow-up studies of children with goiter are needed to formulate recommendations for evaluation with US and fine-needle aspiration.

Radioactive iodine (RAI) therapy for distantly metastatic differentiated thyroid cancer (DTC) in juvenile versus adult patients

In general, juvenile differentiated thyroid carcinoma (DTC) demonstrate indolent characteristics and favorable prognosis are observed in comparison with many other carcinomas. However, recurrence is frequent, necessitating additional treatment, including radioactive iodine (RAI) therapy. In this report, the probability of recurrence, prognostic factors, treatment, and outcomes in both juvenile- and adult-onset DTC were analyzed and compared. At our institution, a total of 1552 DTC patients underwent thyroidectomy and/or lymph node dissection. The patients included 23 in their teens, 118 in their twenties, and 1412 in their thirties or older. The risk factors for distant metastases for DTC were male gender, follicular carcinoma, size of the PTC primary tumor, cervical lymph node metastases from PTC, and the presence of more than two distant metastatic foci. Patients with the highest risk underwent RAI ablation in line with institutional guidelines. Although the overall outcome in our juvenile patients was excellent, during follow-up, 4 (17.4%) of the 23 patients developed recurrent disease: 91.3% achieved complete remission, 4.35% partial remission, and 4.35% stable disease, with no disease-related deaths. Among the 118 patients in their twenties to thirties, 1 (0.8%) experienced progressive disease and disease-related death. A younger age at diagnosis and less radical primary surgery without subsequent RAI ablation are factors strongly predictive of distant metastases in patients with juvenile-onset DTC. To reduce the rate of relapse and improve surveillance for recurrent disease, total thyroidectomy followed by RAI appears to be the most beneficial initial treatment for patients with high- and intermediate-risk juvenile DTC.

Is outcome of differentiated thyroid carcinoma influenced by tumor stage at diagnosis?

BACKGROUND

There is no international consensus on surveillance strategies for differentiated thyroid carcinoma (DTC) after radiotherapy for childhood cancer. Ultrasonography could allow for early detection of DTC, however, its value is yet unclear since the prognosis of DTC is excellent. We addressed the evidence for the question: 'is outcome of DTC influenced by tumor stage at diagnosis?'.

METHODS

A multidisciplinary working group answered the sub-questions: 'is recurrence or mortality influenced by DTC stage at diagnosis? Does detection of DTC at an early stage contribute to a decline in adverse events of treatment?' The literature was systematically reviewed, and conclusions were drawn based on the level of evidence (A: high, B: moderate to low, C: very low).

RESULTS

In children, level C evidence was found that detection of DTC at an early stage is associated with lower recurrence and mortality rates. No evidence was found that it influences morbidity rates. In adults, clear evidence was found that less advanced staged DTC is a favorable prognostic factor for recurrence (level B) and mortality (level A). Additionally, it was found that more extensive surgery increases the risk to develop transient hypoparathyroidism (level A) and that higher doses of radioiodine increases the risk to develop second primary malignancies (level B).

CONCLUSION

Identification of DTC at an early stage is beneficial for children (very low level evidence) and adults (moderate to high level evidence), even considering that the overall outcome is excellent. These results are an important cornerstone for the development of guidelines for childhood cancer survivors at risk for DTC.

Initial presentation and late results of treatment of post-Chernobyl papillary thyroid carcinoma in children and adolescents of Belarus

BACKGROUND

The aim of this population-based study was to evaluate the clinical and pathological characteristics and outcome of papillary thyroid carcinoma (PTC) that have arisen in the Belarusian childhood population exposed to the radioactive fallout from the Chernobyl accident within a long-term period.

PATIENTS AND METHODS

The long-term treatment results were investigated in 1078 children and adolescents (<19 years old) with PTC who were surgically treated during the years 1990 through 2005.

RESULTS

Patients had high rates of metastatic PTC at presentation, with 73.8% of cases having lymph node involvement and 11.1% having distant spread. The most influential factor for lymph node metastases at initial treatment was lymphatic vessel invasion (P < .0001) and for distant metastases, lateral lymph node involvement (P < .0001). The overall survival was 96.9% ± 0.9% with a median follow-up of 16.21 years, and 20-year event-free survival and relapse-free survival were 87.8% ± 1.6% and 92.3% ± 0.9%, respectively. Patients had significantly lower probability of both loco-regional (P < .001) and distant relapses (P = .005) after total thyroidectomy (TT) and radioactive iodine therapy (RAI). For loco-regional relapses after TT, only RAI influenced the prognosis significantly (P < .001). For distant relapses after TT, the refusal to treat with RAI (hazard ratio [HR] = 9.26), vascular invasion (HR = 8.68), and age at presentation (HR = 6.13) were significant risk factors. For loco-regional relapses after non-TT, the principal risk factors were age less than 15 years old at presentation (HR = 5.34) and multifocal growth of tumor (HR = 5.19). For distant relapses after non-TT, the lateral neck metastases were the only unfavorable factor (HR = 9.26).

CONCLUSION

The outcome of PTC both in children and in adolescents exposed to the post-Chernobyl radioiodine fallout was rather favorable. TT with RAI is recommended for minimizing loco-regional or distant relapses.

Recurrent disease in juvenile differentiated thyroid carcinoma: prognostic factors, treatments, and outcomes

The overall prognosis in pediatric differentiated thyroid carcinoma (DTC) is excellent. Recurrent disease is frequent, however, and requires additional treatment. We analyzed the probability of recurrence, prognostic factors, treatment, and outcome of juvenile DTC.

METHODS

Fifty-one DTC patients (32 girls and 19 boys; ≤ 20 y old; mean age, 16.5 y) were treated with (131)I (radioiodine, or radioactive iodine [RAI]); the median follow-up was 10 y. Patients underwent different initial treatments: 46 patients received total thyroidectomy and RAI, 3 patients received total thyroidectomy, and 3 patients received subtotal thyroidectomy. The probability of recurrence and prognostic factors were tested with the Kaplan-Meier method.

RESULTS

Initially, 36 of 51 patients achieved complete remission, 14 of 51 achieved partial remission, and 1 of 51 had progressive disease. By the follow-up, 11 of 51 patients (21.6%) had developed recurrent disease; the median appearance time was 4 y (range, 1-15 y). The probabilities of recurrence were 16.7% at 5 y, 22.3% at 10 y, and 33.3% at 15 and 23 y after the initial treatments. Factors that were strongly predictive of recurrence were age (P = 0.001), initial treatment (P = 0.0001), and tumor multifocality (P = 0.011). Sex, nodal metastases at presentation, distal metastases at presentation, histologic type of the tumor, T stage, and clinical stage had no influence on relapse (P = 0.180, P = 0.786, P = 0.796, P = 0.944, P = 0.352, and P = 0.729, respectively). Patients with recurrent disease, partial remission, and progressive disease were retreated, with either surgery or surgery and RAI, receiving cumulative activities of up to 40 GBq. The overall outcome in our patients was excellent: 90.2% complete remission, 3.92% partial remission, 1.96% stable disease, 1.96% disease-related death, and 1.96% another cause of death.

CONCLUSION

Younger age at diagnosis, less radical primary surgery without subsequent RAI, and tumor multifocality are factors that are strongly prognostic for recurrence. For reducing the rate of relapse and improving surveillance for recurrent disease, total thyroidectomy followed by RAI appears to be the most beneficial initial treatment for patients with juvenile DTC. The use of RAI seems to be safe, with no adverse effects on subsequent fertility and pregnancy or secondary malignancy.

Best practice for the management of pediatric thyroid cancer

The presentation of differentiated thyroid cancer in children often includes dissemination to lymph nodes. Despite this, the long-term prognosis is excellent with appropriate treatment. A few known hereditary syndromes are associated with paediatric thyroid cancer, although most tumours are sporadic. Ultrasound and cytology is used to evaluate suspect thyroid nodules, and treatment consists of surgery, radioactive iodine and thyroxine suppression therapy. Follow-up includes serum thyroglobulin measurements, serial ultrasounds of the neck, radioiodine whole body scans and occasionally other cross-sectional imaging or positron emission tomography. This review focuses on paediatric well differentiated follicular and papillary thyroid cancer, diagnosis and preoperative evaluation, underlying genetic mechanisms, surgery, other treatment options and follow-up.

Surgical management of well-differentiated thyroid carcinoma in children and adolescents: 33 years of experience of a single institution in Serbia

Well-differentiated thyroid carcinoma in children and adolescents is rare but demonstrates aggressive behavior. Gross lymph node metastases and distant metastases are common upon first clinical presentation. During a 33-year period (1981-2014) at the Institute of Oncology and Radiology of Serbia, 62 children and adolescents underwent surgery due to well-differentiated thyroid carcinoma. Mean age was 16.7 (range 7-21) years. At the time of diagnosis 6% of patients had lung metastases. Total thyroidectomy or completion thyroidectomy was performed for all patients followed by central neck dissection and frozen section examination of jugular-carotid compartments. Median follow-up was 10.9 (range 0.69-33.05) years and median tumor size was 20 (range 2-60) mm. Papillary carcinoma was found in 96%, and follicular and Hürthle cell carcinoma in 2% of patients. Multifocal tumors were found in 50% and capsular invasion in 60% of patients. Lymphonodal metastases in either central or lateral neck compartments were found in 73% of patients. Multifocality and capsular invasion were significantly more frequent in patients less than 16 years of age (both p < 0.01). Median disease-free interval had not been reached and overall survival rate was 100%. Well-differentiated thyroid carcinoma in children and adolescents is characterized by a high rate of loco-regional aggressiveness, multifocality, capsular invasion, lymph node metastases and distant metastases at the time of diagnosis. Adequate surgical approaches should be performed for both primary and recurrent disease in young patients with well-differentiated thyroid carcinoma in order to achieve loco-regional disease control and longer disease-free survival.

Paediatric thyroid cancer: the Scottish experience

BACKGROUND AND AIMS

Paediatric thyroid cancer is a rare disease, making diagnosis and treatment particularly challenging. Here we present the Scottish experience of thyroid cancer in the paediatric population and give an overview of how a child or adolescent that presents with a thyroid nodule should be investigated and managed.

METHODS AND RESULTS

Data has been obtained from ISD Scotland, giving population-based information on paediatric thyroid cancer. A literature review has been performed on the management and treatment of thyroid cancer in the younger population. Paediatric thyroid cancer in Scotland is a rare disease, although the incidence is increasing each year. In general, differentiated paediatric thyroid cancer carries a good prognosis, while the results are more mixed in the rarer pathologies such as medullary cancer.

CONCLUSION

Due to the small numbers of patients diagnosed each year in Scotland, it is imperative that these patients are discussed at a multidisciplinary thyroid MDT and managed in a tertiary referral centre by consultants and medical/nursing support staff who have experience in treating these patients.

Thyroid cancer in children and adolescents

PURPOSE OF REVIEW

Paediatric thyroid cancer is a rare disease, but its incidence is rising in recent reports. This review aims at integrating recent findings into the current optimal diagnostic and therapeutic approach.

RECENT FINDINGS

The causal relationship of differentiated thyroid cancer (DTC) to radiation exposure is increasingly unravelled. Research progressively uncovers the genetic basis, such as RET (rearranged during transfection)/papillary thyroid cancer (PTC) rearrangement and RET-mutations. Knowledge of oncogenic signalling pathways nowadays starts to help finetuning diagnosis, prognosis and treatment. This knowledge complements the current state-of-the-art of paediatric thyroid cancer treatment. In childhood, DTC presents at a more advanced stage and implies higher recurrence rates, recurrences often occurring decades later. Treatment should minimize not only these recurrences but also long-term treatment sequelae. Total thyroidectomy and central compartment dissection by a high-volume surgeon and radioactive iodine is the preferred approach for most children with DTC. For children with medullary thyroid cancer within the MEN2 framework, when possible, prophylactic thyroidectomy is performed. Unfortunately, frequently, the diagnosis is still made at a later stage, and then requires total thyroidectomy with dissection of the central compartment and the lateral neck, when involved.

SUMMARY

The management complexity, the essential long-term follow-up and the lifetime burden of eventual complications demands management of paediatric thyroid cancer by physicians with the highest expertise. In such hands, excellent results can be obtained.

[Differentiated thyroid cancer in childhood]

Thyroid carcinoma is a rare disease in children, and is mostly of the papillary histological type. Lymph node metastases are frequent at diagnosis, being present in 23 to 74% of the cases and can reveal the cancer in about one fourth of cases. Lung metastases are present at initial diagnosis in 6 to 20% of cases. The main known risk factor for thyroid cancer is a previous history of radiation exposure. Treatment includes surgery with total thyroidectomy and lymph node dissection and radioiodine therapy in case of extensive disease and distant metastases. Life-long thyroxine treatment is given to all patients. Long term prognosis is favourable, but thyroid cancer related deaths have been reported some decades after initial treatment.