Clinical features, treatment, and long-term outcome of papillary thyroid cancer in children and adolescents without radiation exposure

Historical context, process, and development trends of pediatric thyroid cancer research: a bibliometric analysis

Objective

At present, the structure of knowledge in the field of childhood thyroid cancer is not clear enough, and scholars lack a sufficient understanding of the developing trends in this field, which has led to a shortage of forward-looking outputs. The purpose of this research is to help scholars construct a complete knowledge framework and identify current challenges, opportunities, and development trends.

Methods

We searched the literature in the Web of Science Core Collection database on August 7, 2023 and extracted key information from the top 100 most cited articles, such as the countries, institutions, authors, themes, and keywords. We used bibliometric tools such as bibliometrix, VOSviewer, and CiteSpace for a visualization analysis and Excel for statistical descriptions.

Results

The top 100 most cited articles fluctuated over time, and the research was concentrated in European countries, the United States, and Japan, among which scientific research institutions and scholars from the United States made outstanding contributions. Keyword analysis revealed that research has shifted from simple treatment methods for pediatric thyroid cancer (total thyroidectomy) and inducing factors (the Chernobyl power station accident) to the clinical applications of genetic mutations (such as the BRAF and RET genes) and larger-scale genetic changes (mutation studies of the DICER1 gene). The thematic strategy analysis showed an increasing trend towards the popularity of fusion oncogenes, while the popularity of research on traditional treatments and diagnostics has gradually declined.

Conclusion

Extensive research has been conducted on the basic problems of pediatric thyroid cancer, and there has been significant outputs in the follow-up and cohort analysis of conventional diagnostic and treatment methods. However, these methods still have certain limitations. Therefore, scholars should focus on exploring fusion genes, the clinical applications of molecular targets, and novel treatment methods. This study provides a strong reference for scholars in this field.

Does it work in childhood and adolescence? The predictive role of postoperative/preablative stimulated thyroglobulin levels in paediatric thyroid cancer. A systematic review of the literature

BACKGROUND

Thyroglobulin is a well-established disease marker during follow-up in paediatric differentiated thyroid cancer. However, no conclusive data on the role of endogenously stimulated thyroglobulin after thyroidectomy (ptTg) in predicting disease-specific outcomes are available. This review aims to establish the prognostic value of ptTg in children with DTC.

METHODS

Online medical databases were searched for studies evaluating the association between ptTg and disease-specific outcomes in DTC-affected children. Documents not in English, preclinical studies, other review articles, case reports, and small case series were excluded. The risk of bias was assessed with the QUADAS-2 tool.

RESULTS

Twelve studies, analysing 1043 children in total, were included in the review. They all had a retrospective design and were published between 2016 and 2022. Of all patients, 1008 (97%) and 849 (81%) had undergone thyroidectomy and RAI, respectively. Eight studies (756 children) evaluated the correlation between ptTg and disease persistence/relapse: six reported a significant association between these parameters; a specific ptTg cut-off (10-14 ng/ml) was identified at the multivariate analysis in three studies. The remaining four studies assessed the link between ptTg levels and disease extension, with three reporting a correlation between ptTg and lung/nodal metastases.

DISCUSSION

ptTg is a readily available and inexpensive parameter, bearing a strong prognostic power in identifying disease persistence, relapse, and the presence of metastases in children affected by DTC.

Survival Trends in Pediatric Differentiated Thyroid Cancer: A Middle Eastern Perspective

Pediatric Differentiated Thyroid Cancer (pedDTC) is a rare pediatric malignancy with an increasing incidence over time. To date, there is a paucity of literature specifically addressing pedDTC within the context of Middle Eastern ethnicity. This retrospective study aimed to assess the risk-stratifying factors for overall survival (OS) and event-free survival (EFS) in pediatric DTC patients from Iraq and Jordan. The medical records of 81 patients from two tertiary cancer institutes were retrieved. Kaplan-Meier analysis was employed to investigate OS and EFS, and the Cox proportional hazards model was employed to estimate hazard ratios. All patients underwent surgery and radioactive iodine therapy, with a median age of 14 and an interquartile range of 12-15. Lymph node involvement was observed in 55% of cases, while distant metastases were present in 13.5%. After a median follow-up period of 68 months, the 10-year survival rate was determined to be 94%, while the 10-year EFS rate was 58%. EFS was negatively impacted by cervical lymph node metastases and early age of diagnosis (p ≤ 0.01, each). Therefore, pediatrics with initial cervical lymph node metastases and those diagnosed before puberty tend to experience poorer EFS, which may justify the need for more aggressive management plans.

Risk factors for recurrence of differentiated thyroid carcinoma in children and adolescents: A retrospective cohort study

This study aimed to provide a recent clinical evaluation of the outcome of treatment and the predictors of recurrence for Chinese children and adolescents with differentiated thyroid carcinoma (DTC). This is a retrospective cohort study at the Yunnan Cancer Hospital from May 2002 to August 2021. We analyzed several risk factors related to the recurrence of DTC in children and adolescents. The Chi-square test, Kaplan-Meier log-rank tests, and Cox regression analysis were used in the statistical analysis. A P-value <.05 was considered statistically significant. A total of 103 patients were enrolled, including 68 girls (66.0%) and 35 boys (34.0%) with a median age of 18 years (range: 7-20 years). All enrolled patients received standard treatment. Children (≤14years) tended to have multifocality and higher levels of thyroid imaging reporting and data system, higher pN stage, and higher American Thyroid Association (ATA) pediatric risk compared with adolescents (P < .05). The chief complaints and clinical treatment differed between children and adolescents. During a follow-up of 6 to 239 months (average 74.7 months, median 59 months), all patients survived, but recurrence occurred in 22 patients (22.4%). The disease-free survival rates at 1, 2, 5, and 10 years were 91.2%, 78.4%, 77.1%, and 77.1%, respectively. Univariate Cox regression and log-rank tests showed that positive preoperative thyroglobulin level, bilaterality, extrathyroidal extension, high pT/pN/pM stage, and high ATA pediatric risk were the risk factors for DTC recurrence in children and adolescents. Multivariate Cox regression found that extrathyroidal extension and ATA pediatric risk were independent risk factors for the recurrence of DTC in children and adolescents. Additionally, among the 38 cases with cN0 stage, one who had bilateral, and multifocal thyroid nodules experienced recurrence, while the remaining 37 cases with cN0 stage had no recurrence. In conclusion, compared with adolescents, children present with more highly malignant disease and are more prone to metastasis. The significant risk factors associated with the recurrence of DTC in children and adolescents were positive preoperative thyroglobulin level, bilaterality, high pT/pN/pM stage, extrathyroidal extension, and high ATA pediatric risk, with the latter 2 being independent risk factors. The surgical approach for cN0 patients should be personalized taking into account invasive features.

Thyroid Nodules and Follicular Cell-Derived Thyroid Carcinomas in Children

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

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

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

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

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

Aggressiveness of Differentiated Thyroid Carcinoma in Pediatric Patients Younger Than 16 years: A Propensity Score-Matched Analysis

Background

The biological behavior of thyroid cancer in children has been known to be different from that in adults. We sought to understand the differences between DTC presentation in pediatric (<16 years) and adult patients, to guide better prognosis and clinical treatments.

Methods

This retrospective study included 48 pediatric patients younger than 16 years who underwent initial thyroid surgery and were diagnosed with DTC between January 1992 and December 2014 at Yonsei University in Seoul, South Korea. For a 1:4 propensity score-matched analysis, adult patients with matched sex and cancer size were included.

Results

The mean age was 12.54 ± 3.01 years. Total thyroidectomy (70.8%) without lateral lymph node dissection (47.9%) was the most commonly performed surgery. Central (73.9%) and lateral neck node metastases (62.5%) were common; distant metastasis was observed in 2 (4.2%) patients and recurrence occurred in 11 (22.9%). In propensity score-matched analysis, central lymph node metastasis and lateral neck node metastasis were significantly more frequent in pediatric patients. Symptoms were more common in the pediatric group than in the adult group (p < 0.001). In stratified cox regression, pediatric patients were more likely to experience recurrence [HR 5.339 (1.239–23.007)]. In stratified log-rank analysis, recurrence-free survival was significantly different between the adult and pediatric groups (p = 0.0209).

Conclusion

DTC in the pediatric group revealed more aggressive patterns than in the adult group with the same cancer size. Central lymph node metastasis and lateral neck node metastasis were more frequent. Stratified log-rank analysis revealed that recurrence was significantly higher in pediatric patients than in matched adult patients.

Tumor size is an independent negative prognostic factor for event free survival in children with differentiated thyroid cancer

BACKGROUND

The incidence of pediatric differentiated thyroid carcinoma (DTC) is increasing. Despite the advanced disease at presentation, the overall prognosis of DTC in children is excellent. The aim of this study is to investigate the risk stratifying factors for event free survival (EFS) of pediatric DTC from Middle Eastern ethnicity.

METHODS

Eighty-eight patients aged ≤18 years with diagnosis of primary DTC were retrospectively analyzed. Cox proportional hazards model were used to calculate Hazard Ratios (HR) and Kaplan-Meier analysis were conducted to investigate EFS.

RESULTS

Eighty-eight (23 males and 65 females) pediatric DTCs who underwent surgery and radioactive iodine therapy had been reported (median age at diagnosis 15 years; range 5.9-17.9), with lymph node metastasis (LNM) noted in 70.5% and distant metastasis in 13.6%. Mean follow-up was 8.4 years. Ten-year overall survival rate was 98.4% while 10-year EFS was 79.2%. EFS was negatively impacted by the presence of LNM, distant metastasis and tumor size >4cm. American Thyroid Association risk stratification did not impact EFS in our cohort. Multivariate analysis revealed tumor size >4cm (HR = 5.34; 95% confidence interval (CI) = 1.36 - 20.22; p = 0.0177) and distant metastasis (HR = 8.73; 95% CI = 1.48 - 60.05; p = 0.0154) as independent negative prognostic factors for EFS.

CONCLUSIONS

Primary tumor size and the presence of distant metastasis at diagnosis are the only independent prognostic risk factors for EFS in pediatric DTC in Middle Eastern ethnicity. Children with tumor size over 4cm had poor EFS, which may justify the need of more aggressive treatment and frequent follow-up.

Prognostic analysis of recurrence in children and adolescents with differentiated thyroid cancer

Background:

The standard treatment for pediatric differentiated thyroid carcinoma (DTC) still requires consideration because of a lack of clinical evidence. The purpose of this study was to summarize the clinical experiences and explore the risk factors for post-operative recurrence through a retrospective analysis to develop better clinical strategies for pediatric DTC.

Methods:

This study retrospectively analyzed children and adolescents with DTC who were treated between January 1999 and December 2014 at the Cancer Hospital, Chinese Academy of Medical Sciences. Clinicopathological results and outcomes were collected. A log-rank test of Kaplan-Meier curves and the Cox regression model were used to determine the factors associated with recurrence.

Results:

Data of 150 patients were collected in this study. During the follow-up, there was only one disease-related death. The recurrence rates at 3, 5, and 10 years were 13.6%, 18.7%, and 28.6%, respectively. There was a significant difference in the rate of recurrence according to age (P < 0.001), extrathyroidal extension (P < 0.001), lymph node metastasis (P = 0.023), and invasion of the trachea and esophageal wall (P = 0.004). Cox regression analysis demonstrated that age (P = 0.006) and extrathyroidal extension (P = 0.013) were significant dependent factors of post-operative recurrence.

Conclusions:

The prognosis of DTC in children and adolescents is favorable. A close follow-up is recommended because of the high recurrence rate. A comparatively higher recurrence rate was observed in the younger age group, and new age-based divisions may be needed to conveniently evaluate the possibility of recurrence.

Communicating with residents about 10 years of scientific progress in understanding thyroid cancer risk in children after the Fukushima Dai-ichi Nuclear Power Station accident

After the Fukushima Dai-ichi Nuclear Power Station (FDNPS) accident in 2011, radiation-related risk of childhood thyroid cancer remains a matter of concern among residents living in areas affected by radioactive plumes. As a countermeasure to that, the Fukushima Prefectural Government-in conjunction with Fukushima Medical University-began the Fukushima Thyroid Examination (FTE) campaign in 2011. As 116 definite or suspected thyroid cancer cases were found after the first round of FTE and the total number of cases was >240 as of June 2020, residents' concerns have deepened. Some researchers claim that these cases are radiation-induced, while others claim a screening effect (because FTE uses high-resolution ultrasound equipment) and express concern about over-diagnosis. Researchers therefore must address two conflicting issues: one is to elucidate radiation effects on thyroid cancer, which requires continuation of FTE; the other is to solve ethical problems associated with FTE. As to over-diagnosis, surgeons claim that early diagnosis benefits children by reducing the side-effects of treatment and prolonging disease-free survival, while cancer epidemiologists claim that early diagnosis will result in overtreatment without reducing the death rate. 'To receive FTE or not' and 'to stop FTE or not' are ongoing dilemmas for children (and their parents) and other stakeholders, respectively. To facilitate building a consensus among stakeholders, I overview recent findings about dose reconstruction, the dose-response relationship of thyroid cancer, over-diagnosis, and the natural history of thyroid cancer, all of which contribute to judging the risk-benefit balance of thyroid screening.

Total Thyroidectomy vs Thyroid Lobectomy for Localized Papillary Thyroid Cancer in Children: A Propensity-Matched Survival Analysis

BACKGROUND

Current guidelines recommend total thyroidectomy (TT) and radioablation for most papillary thyroid cancer (PTC) in children. These guidelines have been criticized as aggressive, especially for early-stage PTC, as it likely does not influence patient survival and results in life-long thyroid hormone replacement. We sought to study whether the extent of thyroidectomy (TT vs thyroid lobectomy [TL]) influences overall and disease-specific survival in children with localized PTC.

METHODS

The National Cancer Database and the Surveillance, Epidemiology, and End Results registries were queried. Patients 18 years or younger with low-risk PTC between 2004 and 2016 were included. Using a 1:1 propensity score matching, patients who underwent TT were matched for age, sex, race, year of diagnosis, and tumor size with a similar cohort of patients who underwent TL. Primary end points were overall survival and disease-specific survival.

RESULTS

There were 3,500 patients identified as surgically treated for PTC, of which 1,325 patients met inclusion criteria for matching. Three hundred and twenty-six patients were matched. One hundred and sixty-three patients had TT; 140 were female and mean age was 16 years (interquartile range [IQR] 13 to 17 years). One hundred and sixty-three patients had TL; 140 were female and mean age was 16 years (IQR 14 to 17 years). Median follow-up was 5.0 years (IQR 2.8 to 8 years) and 8.3 years (IQR 3.6 to 14.4 years) in the National Cancer Database and Surveillance, Epidemiology, and End Results cohorts, respectively. There was no statistically significant difference in overall survival or disease-specific survival in patients with PTC < 4 cm, regardless of whether patients underwent TT or TL (p = 0.32 for National Cancer Database registry and p = 0.67 for Surveillance, Epidemiology, and End Results registry).

CONCLUSIONS

This study suggests that the extent of thyroidectomy does not influence survival for pediatric patients with early-stage PTC and that TL might be adequate in this patient population.

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.

Synergistic Effects of Lenvatinib (E7080) and MEK Inhibitors against Anaplastic Thyroid Cancer in Preclinical Models

E7080, known as lenvatinib, is an oral multitargeted tyrosine kinase inhibitor that has been shown to improve the survival rate of patients with radioiodine-refractory thyroid cancer. However, a majority of patients do not continue lenvatinib intake due to disease progression or significant toxicity. To improve treatment success rates, we propose the combination of lenvatinib with mitogen-activated protein kinase (MEK) inhibitors. To test this hypothesis, we tested the effects of lenvatinib with the MEK inhibitor U0126 in vitro using two human anaplastic thyroid cancer (ATC) cell lines, 8505C and TCO1, and with another MEK inhibitor, selumetinib (AZD6244), in an ATC mouse model. We found that the combination of lenvatinib with MEK inhibitors enhanced the antitumor effects of monotherapy with either agent in vitro and in vivo, and these effects may be through the AKT (Protein Kinase B) and extracellular signal-regulated kinase (ERK) signaling pathways. Furthermore, the combination does not have significant adverse effects in the ATC mouse models in terms of body weight, blood biochemical parameters, and histopathology. In conclusion, the combination of lenvatinib with an MEK inhibitor is a potentially viable therapeutic approach for ATC treatment.

Management of Differentiated Thyroid Carcinoma in Pediatric Patients

Differentiated thyroid carcinomas are rare in young children but represent almost 10% of all malignancies diagnosed in older adolescents. Differentiated thyroid carcinoma in children is more likely to demonstrate nodal involvement and is associated with higher recurrence rates than seen in adults. Decisions regarding extent of surgical resection are based on clinical and radiologic features, cytology, and risk assessment. Total thyroidectomy and compartment-based resection of involved lymph node basins form the cornerstone of treatment. The use of molecular genetics to inform treatment strategies and the use of targeted therapies to unresectable progressive disease is evolving.

Inherited Thyroid Tumors With Oncocytic Change

Familial non-medullary thyroid carcinoma (FNMTC) corresponds to 5-10% of all follicular cell-derived carcinoma (FCDTC). Oncocytic thyroid tumors have an increased incidence in the familial context in comparison with sporadic FCDTC, encompassing benign and malignant tumors in the same family presenting with some extent of cell oxyphilia. This has triggered the interest of our and other groups to clarify the oncocytic change, looking for genetic markers that could explain the emergence of this phenotype in thyroid benign and malignant lesions, focusing on familial aggregation. Despite some advances regarding the identification of the gene associated with retinoic and interferon-induced mortality 19 (GRIM-19), as one of the key candidate genes affected in the "Tumor with Cell Oxyphilia" (TCO) locus, most of the mutations follow a pattern of "private mutations", almost exclusive to one family. Moreover, no causative genetic alterations were identified so far in most families. The incomplete penetrance of the disease, the diverse benign and malignant phenotypes in the affected familial members and the variable syndromic associations create an additional layer of complexity for studying the genetic alterations in oncocytic tumors. In the present review, we summarized the available evidence supporting genomic-based mechanisms for the oncocytic change, particularly in the context of FNMTC. We have also addressed the challenges and gaps in the aforementioned mechanisms, as well as molecular clues that can explain, at least partially, the phenotype of oncocytic tumors and the respective clinico-pathological behavior. Finally, we pointed to areas of further investigation in the field of oncocytic (F)NMTC with translational potential in terms of therapy.

Long-term outcome of differentiated thyroid cancer in children and young adults: risk stratification by ATA criteria and assessment of pre-ablation stimulated thyroglobulin as predictors of disease persistence

PURPOSE

Differentiated thyroid cancer (DTC) has an increasing incidence in childhood and adolescence but long-term outcome data are limited. We aimed to identify possible risk factors associated with disease persistence, with special focus on the usefulness of ATA risk stratification system and pre-ablation stimulated thyroglobulin (Tg) levels.

METHODS

We retrospectively studied 103 patients, 79 females (76.7%), aged 15.6 ± 3.2 years (range 5-21 years) who underwent total thyroidectomy for DTC. Patients were classified by ATA risk stratification criteria as low, intermediate, and high risk for recurrence. All, except five with papillary microcarcinoma, received radioactive iodine (RAI) treatment.

RESULTS

At diagnosis, 44.7% of patients had cervical lymph node and 7.8% pulmonary metastases. Amongst the 72 patients with long-term follow-up data, 31.9% had persistent disease. Lymph node as well as pulmonary metastases and increased pre-ablation stimulated thyroglobulin (Tg) levels were associated with persistent disease. The risk of persistent disease was significantly higher in both the intermediate- (OR 17.95; 95% CI 2.66-120.94, p < 0.01) and high-risk (OR 17.65; 95% CI 4.47-69.74, p < 0.001) groups. ROC curve analysis showed that a pre-ablation Tg level higher than 14 ng/ml had a sensitivity of 94.7% to predict persistence, corresponding to a positive (PPV) and negative predictive values (NPV) of 66.7% and 93.8%, respectively.

CONCLUSIONS

ATA risk stratification was validated in our population of children and young adults with DTC. Moreover, pre-ablation stimulated Tg levels of <14 ng/ml were associated with a low risk of long-term persistence and may therefore serve as a marker to identify patients who may need less intensive surveillance.

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).

Overdiagnosis of Juvenile Thyroid Cancer

Overdiagnosis is the detection of a disease that does not do any harm to the patient throughout the lifetime. Thyroid cancer in children is a rare disease; however, since 2011, many children in Fukushima, Japan, have been diagnosed with it, and the number has shown a steady increase to over 200 cases at present. Some experts have stated that this phenomenon is due to overdiagnosis caused by thyroid ultrasound (US)-based thyroid screening detecting self-limiting thyroid cancer, which will not lead to clinical symptoms in the future. Harm caused by overdiagnosis of thyroid cancer is more serious in the young, since it is difficult to perform active surveillance and children diagnosed with cancer are likely to suffer from stigma. Thus, overdiagnosis of thyroid cancer in the young is not only a health problem but also a problem of human rights. Conflicts of interest among people related to screening programs and some experts with incomplete knowledge on overdiagnosis help to spread misleading opinions together with fear of radiation exposure among residents, which has led to their erroneous understanding of the nature of US-based thyroid screening. Scientific and honest discussions among experts to enhance education of residents and consideration of medical ethics are crucial to prevent the expansion of overdiagnosis.

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

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

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

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

Prognosis study, level IV, retrospective case series.

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.

A novel therapeutic approach for anaplastic thyroid cancer through inhibition of LAT1

A novel therapeutic approach is urgently needed for patients with anaplastic thyroid cancer (ATC) due to its fatal and rapid progress. We recently reported that ATC highly expressed MYC protein and blocking of MYC through its selective inhibitor, JQ1, decreased ATC growth and improved survival in preclinical models. One of the important roles of MYC is regulation of L-neutral amino acid transporter 1 (LAT1) protein and inhibition of LAT1 would provide similar anti-tumor effect. We first identified that while the human ATC expresses LAT1 protein, it is little or not detected in non-cancerous thyroidal tissue, further supporting LAT1 as a good target. Then we evaluated the efficacy of JPH203, a LAT1 inhibitor, against ATC by using the in vitro cell-based studies and in vivo xenograft model bearing human ATC cells. JPH203 markedly inhibited proliferation of three ATC cell lines through suppression of mTOR signals and blocked cell cycle progression from the G0/G1 phase to the S phase. The tumor growth inhibition and decrease in size by JPH203 via inhibition of mTOR signaling and G0/G1 cell cycle associated proteins were further confirmed in xenograft models. These preclinical findings suggest that LAT1 inhibitors are strong candidates to control ATC, for which current treatment options are highly limited.

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

Introduction

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

Material and Methods

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

Results

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

Conclusion

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

Histopathological analysis of papillary thyroid carcinoma detected during ultrasound screening examinations in Fukushima

Thyroid ultrasound screening of young residents in Fukushima Prefecture, Japan, showed a high detection rate of papillary thyroid carcinoma (PTC). Detailed morphological analysis of these tumors was not presented to date. This study sets out to evaluate changes in histopathological and invasive characteristics of Fukushima PTC with time after the nuclear accident of March 2011 in all available cases and in different age subgroups. Histological specimens of 115 PTCs from patients aged 18 years or younger at the time of the Fukushima Dai‐ichi Nuclear Power Plant accident, who underwent surgical resection at Fukushima Medical University during 2012‐2016, were reviewed. Patients were divided into those treated during the first 4 years after the accident (n = 78, shorter‐onset) or later (n = 37, longer‐onset). The whole group and 3 age subgroups: children (aged less than 15 years), adolescents (aged from 15 to less than 19 years), and young adults (aged from 19 years) at surgery were analyzed. No statistically significant time‐related changes in tumor structure or invasiveness were found in the whole group or in age‐matched subgroups. Statistically significant age‐related downtrend was observed for intrathyroid spread in the whole group of patients. The absence of temporal changes in tumor morphological characteristics and tumor invasiveness strongly suggests common etiology of the shorter‐ and longer‐onset Fukushima PTCs, which are unlikely related to the effect of exposure to very low doses of radiation.

Treatment outcomes in pediatric differentiated thyroid carcinoma

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Practical Initial Risk Stratification Based on Lymph Node Metastases in Pediatric and Adolescent Differentiated Thyroid Cancer

BACKGROUND

Data on the risk stratification of pediatric differentiated thyroid cancer (DTC) remain scarce. This study aimed to evaluate the predictors of structural persistent/recurrent disease and revise an initial risk-stratification system in pediatric DTC patients.

METHODS

This retrospective cohort study included 203 patients (aged <20 years) from two tertiary referral centers in Korea. The extent of cervical lymph node (LN) metastasis was classified based on the location or number of metastatic LNs.

RESULTS

During a median follow-up duration of 5.5 years, structural persistent/recurrent disease was observed in 51 (25%) patients, including 22 (11%) with distant metastases. The presence of extrathyroidal extension (ETE) and lateral cervical LN metastases or more than five metastatic LNs were independent predictors for structural persistent/recurrent disease. The presence of bilateral lateral cervical LN metastases or >10 metastatic LNs were independent predictors for distant metastasis. A total of 67 (33%), 72 (35%), and 64 (32%) patients were classified into the low-, intermediate-, and high-risk groups, respectively, based on the presence of ETE and the extent of cervical LN metastases. Compared to the low-risk group, the intermediate- and high-risk groups had a significantly greater risk of structural persistent/recurrent disease (hazard ratio = 7.32, p = 0.008, and hazard ratio = 24.28, p < 0.001, respectively).

CONCLUSIONS

This revised initial risk-stratification system based on the presence of ETE and the extent of cervical LN metastasis is useful for predicting the clinical outcomes of pediatric DTC patients. The findings could facilitate the practical use of a risk-stratification system.

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.

Comparative histopathological analysis of sporadic pediatric papillary thyroid carcinoma from Japan and Ukraine

This study set out to compare structural and invasive characteristics of sporadic papillary thyroid carcinoma (PTC) in age-matched groups of children and adolescents of Japan and Ukraine to provide detailed histopathological analysis of tumors from different geographical areas with different iodine intake. A total of 348 (160 Japanese and 188 Ukrainian) PTCs from patients without radiation history were analyzed initially as a combined pediatric group and then subdivided into childhood (aged ≤14 years) and adolescent (aged from 15 to ≤18 years) age series. On multivariate comparison, the Japanese pediatric PTC was characterized by a higher sex ratio (p=1.504E-4), and a higher frequency of microcarcinoma (p=0.039), papillary dominant growth pattern (p=0.024), focal oxyphilic cell metaplasia (p=7.644E-6), intrathyroid spread (p=0.010), lymphatic/vascular invasion (p=0.01) and regional lymph node metastases (p=3.540E-6). In the Ukrainian group, multifocal (p=0.004) and non-encapsulated tumors with the solid-trabecular growth pattern (p=0.05) were more frequent. Childhood Japanese PTCs differed from Ukrainian PTCs by more pronounced invasive properties such as lymphatic/vascular invasion and nodal disease, but did not differ by the dominant growth pattern. In adolescents, the differences were detected not only for lymph node metastases, but also for a higher frequency of the papillary dominant pattern in Japanese PTC. Overall, significantly higher frequencies of oxyphilic cell metaplasia and more pronounced invasive features observed in the Japanese PTC in both age-matched series represent the major differences between the tumors from two geographical areas.

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.

Prognostic Factors for Early and Long-Term Remission in Pediatric Differentiated Thyroid Carcinoma: The Role of Sex, Age, Clinical Presentation, and the Newly Proposed American Thyroid Association Risk Stratification System

BACKGROUND

The incidence of pediatric differentiated thyroid carcinoma (DTC) has been rising in recent years, and the main risk factors for recurrence are lymph node and distant metastasis at diagnosis. Other clinical features remain unclear, such as the impact of age, sex, and puberty. Furthermore, until now, this population has been treated using the same strategies used to treat adults. In 2015, the American Thyroid Association (ATA) published the first guidelines targeted at this age group. The aims of this study were to investigate the prognostic factors for early and long-term remission and also to validate the ATA risk stratification proposal in a population outside the United States.

METHODS

Clinical records from 118 patients <18 years old followed in two referral centers were reviewed. The median age was 12 years (range 4-18 years), and 20.3% (24 patients) were <10 years old at diagnosis. The median follow-up was 9.1 years. The majority were female (72%) and received total thyroidectomy and radioiodine therapy (RAI), and 61.8% were treated with more than one dose of RAI. The majority were classified as high risk (48.3%) by the new ATA pediatric guidelines due to distant metastasis (30 patients) or extensive lymph node involvement (27 patients). The remained were classified as low risk (31.3%) and intermediate risk (20.4%).

RESULTS

Females with no lymph node or distant metastasis and low ATA pediatric risk were more likely to have no evidence of disease (p < 0.05) within the first year and also in the long term. In this study, age did not significantly predict outcomes. Furthermore, patients also benefitted from multiple doses of RAI, but when the cumulative activity was >400 mCi, this benefit was diminished.

CONCLUSIONS

This study shows that the ATA risk stratification proposal for pediatric patients is useful in predicting early and long-term outcomes in pediatric patients with DTC. In addition, it shows that sex and metastatic disease are important prognostic factors in pediatric populations.

Surgical management of papillary thyroid carcinoma in childhood and adolescence: an Italian multicenter study on 250 patients

PURPOSE

The extent of surgery for pediatric papillary thyroid carcinoma is debatable. The aim of this study was to evaluate the feasibility of offering pediatric patients a tailored surgical approach based on certain clinical features.

METHODS

A national multicenter retrospective review of 250 pediatric patients treated for papillary thyroid carcinoma in a 14-year period was performed. Outcomes of interest included tumor-related features, type of surgery, surgical morbidity, disease-free and overall survival rates. Recurrence was thoroughly analyzed with particular focus on how it correlated with certain patient- and tumor-related features.

RESULTS

The majority of patients (58.8 %) had tumors >2 cm in size. Nodal involvement occurred in 115/250 (46 %) patients and distant metastasis in 4 % (10/250). Total thyroidectomy and lobectomy were performed in 90.4 % (226/250) and 9.6 % (24/250) of patients, respectively. The overall rate of surgical complications was 20.8 % (52/250). These included transient and permanent hypoparathyroidism (13.6 and 4.4 %, respectively), and vocal fold palsy (2.8 %). All surgical complications occurred exclusively in the total thyroidectomy group. The rate of recurrent disease was 12 % (30/250) with the vast majority of recurrences (96.6 %) occurring in the total thyroidectomy group. The risk of recurrence correlated significantly with certain tumor-related features (size > 2 cm, multifocality, extrathyroidal invasion, nodal positivity, and distant metastasis). However, it did not correlate with the patient's age or sex. Overall survival was 100 %.

CONCLUSION

Pediatric patients are likely to benefit from a tailored surgical strategy. Uniformly offering patients total thyroidectomy seems to be an overly radical approach.

Primary ectopic substernal thyroid cancer with trachea relapse: a case report and opinions of management

Background

Ectopic substernal thyroid is a rare symptom of thyroid disease that entirely results from the developmental defects at early stages of thyroid embryogenesis and during its descent. Cases were seldom reported as primary ectopic substernal thyroid cancer, especially those with severe local invasion and tracheal relapse.

Case Presentation

In this report, the patient presented odynophagia and a sense of progressing swallowing obstruction. She underwent total thyroidectomy and lump resection. However, she refused to use postoperative radioactive iodine or take adjuvant external-beam radiotherapy, except for thyroid hormone replacement therapy. Tracheal relapse was observed after 6 months. Tracheal stent was used to reconstruct the airway twice.

Conclusions

Trachea invasion might be a worse independent predictor of prognosis than any others and should be given particular attention. Furthermore, tracheal stent might be a palliative option for patients with tracheal relapse.

Recombinant human thyrotropin preparation for adjuvant radioiodine treatment in children and adolescents with differentiated thyroid cancer

AIM

Although recombinant human thyrotropin (rhTSH) is widely used in treating differentiated thyroid cancer (DTC), almost all clinical investigation has been in adults. The aim of our retrospective study was to evaluate outcomes of adjuvant, rhTSH-aided radioiodine treatment in children/adolescents with DTC and to compare them to (131)I therapy during l-thyroxin withdrawal (THW).

METHODS

Patients with the diagnosis of DTC who were ≤18 years of age and had no signs of persistent disease at the time of (131)I treatment were included; 48 patients were treated after rhTSH (rhTSH group) and 82 after THW group. The median time of follow-up after therapy was 67 months and was longer in the THW group (99 vs 43 months, P<0.05).

RESULTS

On the day of (131)I administration, all but one patient had TSH levels above 25 μIU/ml. Peak TSH concentration was significantly higher in the rhTSH group (152 μIU/ml vs 91 μIU/ml). Similarly, the thyroglobulin concentration was higher in the rhTSH group (9.7 ng/ml vs 1.8 ng/ml). No side effects requiring medical intervention were recorded after rhTSH administration. The evaluation of disease outcomes during TSH stimulation (6-18 months after (131)I treatment) revealed equal rates of thyroid ablation (71%) in both groups. During subsequent follow-up, five patients showed recurrence (P>0.05).

CONCLUSIONS

In children/adolescents, rhTSH-aided adjuvant radioiodine treatment is associated with rates of remnant ablation and short-term recurrence similar to THW. As this preparation has several advantages over THW, rhTSH may become the preferred method of TSH stimulation once studies of long-term outcomes show non-inferiority to THW in this age group.

Follicular variant papillary thyroid carcinoma in a pediatric population

BACKGROUND

Follicular variant of papillary thyroid carcinoma (FVPTC) has been shown to be an intermediate entity between papillary (PTC) and follicular/Hurtle cell (FTC) thyroid carcinoma in adults. However, the tumor characteristics and prognosis of FVPTCs has not been studied in the pediatric population and is the focus of the current study

METHODS

All pediatric patients ≤ 19 years of age with differentiated thyroid cancer (PTC, FVPTC, or FTC) were identified from the SEER registry from 1988-2009. Patients were divided into groups based on their histology. Adjusted odds ratios (ORs) for demographic, tumor, and treatment characteristics, as well as hazard ratios (HRs) for overall (OS) and disease-specific survival (DSS) were calculated for FVPTC.

RESULTS

Of 1,956 patients, 445 (22.7%) had FVPTC. Compared to PTCs, FVPTCs were larger (OR: 2.03, CI:1.35-3.06), node negative (OR: 2.26, CI:1.61-3.19), occurred more often in patients < 15 years of age (OR: 1.58, CI:1.10-2.27), and had a partial thyroidectomy (OR: 1.61, CI:1.01-2.57). Conversely, compared to FTC, FVPTCs tumors were smaller (OR: 2.78, CI:1.70-4.53), node positive (OR: 5.26, CI:2.74-10.11), a first cancer (OR: 4.98, CI:2.48-9.99), and more often had a total thyroidectomy (OR: 2.84, CI:1.70-4.76). Only tumor size > 4 cm (HR: 13.92, CI:1.24-156.72) influenced OS for patients with FVPTC. There was no significant difference in OS or DSS between groups.

CONCLUSIONS

In pediatric patients ≤ 19 years of age, FVPTCs have intermediate tumor features compared to PTC and FTC, but a similar OS and DSS. All pediatric patients with thyroid cancer require lifelong surveillance. However, FVPTCs > 4 cm may warrant closer follow-up due to an increased risk of death.

Conservative or radical surgery for pediatric papillary thyroid carcinoma: A systematic review of the literature

BACKGROUND

Pediatric papillary thyroid carcinoma (PTC) is characterized by an aggressive clinical course. Early diagnosis is a challenge and treatment consists principally of partial or total thyroidectomy±neck dissection and radioactive iodine therapy. Due to the rarity of PTC in children, there is no consensus on optimal surgical treatment.

METHODS AND RESULTS

A literature search was carried out using PubMed, Embase, Medline, Cochrane and Web of Science. Seven studies (489 patients) investigating the outcome of surgically managed pediatric PTC were identified. No clear advantage in survival or recurrence rate was found for total thyroidectomy compared to other surgical approaches.

CONCLUSION

Despite the aggressive behavior of PTC, prognosis is good, with low mortality. After removal of disease and prevention of recurrence, reduction of iatrogenic complications are a priority in this age group. Due to the paucity of available evidence, this review cannot recommend conservative or radical surgery for pediatric papillary thyroid carcinoma. To answer this question, we recommend the establishment of a randomized controlled trial with adequately matched baseline variables.

Strong Neck Accumulation of 131I Is a Predictor of Incomplete Low-Dose Radioiodine Remnant Ablation Using Recombinant Human Thyroid-Stimulating Hormone

The purpose of this study was to identify the factors that predict incomplete low-dose radioiodine remnant ablation (RRA) with recombinant human thyroid-stimulating hormone (rhTSH) and to report the adverse events associated with this treatment. Between 2012 and 2014, 43 consecutive patients with thyroid cancer received low-dose RRA with rhTSH after total thyroidectomy. We retrospectively investigated the adverse events during low-dose RRA and during diagnostic whole body scan (DxWBS) using rhTSH, and analyzed the rate of RRA completion and the associations between RRA completion and various clinical/pathological factors. Complete RRA was seen in 33 (76.7%) patients, and incomplete RRA was observed in 10 (23.3%). Patients with incomplete RRA had stronger neck accumulation of 131I than those with complete RRA (P < 0.001). Adverse events at RRA and DxWBS were seen in 12 and 9 patients, respectively. All events at RRA were grade 1, with one exception (grade 2 vertigo after rhTSH administration). The rate of adverse events at DxWBS was significantly higher in patients with adverse events seen at RRA (risk ratio, 3.778, P = 0.008). Strong neck accumulation of 131I is significant independent predictor of incomplete low-dose RRA. The risk of adverse events at DxWBS was higher in patients who experienced adverse events at RRA than in those who did not.

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 Thyroid Microcarcinoma

BACKGROUND

Thyroid microcarcinomas (TMCs) are increasing in the general population, most commonly in older individuals; however, the incidence, characteristics, and outcomes of TMCs in pediatric patients has not been studied.

METHODS

All patients ≤19 years of age with differentiated thyroid carcinoma (DTC) were identified from the surveillance, epidemiology, and end results registry from 1988 to 2009. Patients were divided into two groups based on tumor siz e: TMCs (≤1 cm) and tumors >1 cm. Demographic, tumor, and treatment characteristics, as well as overall survival (OS) and disease-specific survival (DSS), were compared between the two groups. The TMC group was analyzed separately for predictors of overall and disease-specific death.

RESULTS

Of 1825 pediatric DTC patients, 8.4 % had a TMC, and, over the past decade, the incidence has decreased (6.5 vs 14.5 %; p < 0.001). Compared to patients with DTCs >1 cm, TMCs were more likely to have papillary histology, negative lymph nodes, be treated with a partial thyroidectomy [odds ratio (OR) 3.46, CI 2.02-5.93] and not receive radioiodine (OR 1.77, CI 1.10-2.83). Neither OS (TMC: 253.59 months; DTC >1 cm: 257.97 months) nor DSS (TMC: 256.38 months; DTC >1 cm: 260.77 months) differed between groups. Predictors of decreased OS in the entire cohort included secondary malignancy status (p = 0.001), black race (p = 0.006) and follicular or Hurthle histology (p = 0.001). In patients with primary TMC, only follicular or Hurthle histology (p = 0.001) predicted decreased OS.

CONCLUSIONS

TMCs in patients ≤19 years of age are declining and comprise <10 % of pediatric thyroid malignancies. TMCs are most commonly treated with a partial thyroidectomy not followed by radioiodine, and have an excellent OS and DSS.

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.

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.

Analysis of thyroid malignant pathologic findings identified during 3 rounds of screening (1997-2008) of a cohort of children and adolescents from belarus exposed to radioiodines after the Chernobyl accident

BACKGROUND

Recent studies of children and adolescents who were exposed to radioactive iodine-131 (I-131) after the 1986 Chernobyl nuclear accident in Ukraine exhibited a significant dose-related increase in the risk of thyroid cancer, but the association of radiation doses with tumor histologic and morphologic features is not clear.

METHODS

A cohort of 11,664 individuals in Belarus who were aged ≤18 years at the time of the accident underwent 3 cycles of thyroid screening during 1997 to 2008. I-131 thyroid doses were estimated from individual thyroid activity measurements taken within 2 months after the accident and from dosimetric questionnaire data. Demographic, clinical, and tumor pathologic characteristics of the patients with thyroid cancer were analyzed using 1-way analysis of variance, chi-square tests or Fisher exact tests, and logistic regression.

RESULTS

In total, 158 thyroid cancers were identified as a result of screening. The majority of patients had T1a and T1b tumors (93.7%), with many positive regional lymph nodes (N1; 60.6%) but few distant metastases (M1; <1%). Higher I-131 doses were associated with higher frequency of solid and diffuse sclerosing variants of thyroid cancer (P < .01) and histologic features of cancer aggressiveness, such as lymphatic vessel invasion, intrathyroidal infiltration, and multifocality (all P < .03). Latency was not correlated with radiation dose. Fifty-two patients with self-reported thyroid cancers which were diagnosed before 1997 were younger at the time of the accident and had a higher percentage of solid variant cancers compared with patients who had screening-detected thyroid cancers (all P < .0001).

CONCLUSIONS

I-131 thyroid radiation doses were associated with a significantly greater frequency of solid and diffuse sclerosing variants of thyroid cancer and various features of tumor aggressiveness.

Radiation exposure and the risk of pediatric thyroid cancer

It has been more than three years since the unprecedentedly massive earthquake and tsunami struck eastern Japan on March 11, 2011, and the large accident occurred at the Fukushima Daiichi Nuclear Power Plant. To investigate the influence of radiation exposure, thyroid ultrasonography has been provided preliminarily for 360,000 children who lived in Fukushima Prefecture at the time of the accident. As of September 2013, 59 children had been diagnosed with thyroid cancer by fine-needle aspiration cytology, and 34 children had been treated surgically and ultimately diagnosed with papillary thyroid cancer. Here, I would like to describe the characteristics of pediatric thyroid cancer and typical thyroid images obtained by ultrasonography.

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.

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.