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

Molecular Landscape and Therapeutic Strategies in Pediatric Differentiated Thyroid Carcinoma

There has been significant progress in understanding the molecular landscape of pediatric differentiated thyroid carcinoma (DTC) over the past 2 decades. Classification of pediatric DFC into 3 tiers, RAS-like mutant, BRAF mutant, and kinase fusions, accurately reflects an increasing risk for invasive behavior, including regional and distant metastasis. In clinical practice, somatic oncogene testing for nodules with indeterminate cytology per the Bethesda System for Reporting Thyroid Cytopathology provides objective data to optimize surgical planning. In addition, knowledge of the somatic oncogene for widely invasive carcinomas allows for incorporation of oncogene-specific inhibitory therapy both in the adjuvant and neoadjuvant setting. In the present review, we review the risk factors, clinical presentation, and evaluation of pediatric DTC, highlighting the correlation among ultrasound features, cytology, and oncogenic driver of the tumor. We subsequently propose an integrated, multimodal approach that can be used to improve diagnostic accuracy and reliability for preoperative planning as well as identify and discuss which pediatric patients may benefit from systemic oral targeted therapy.

Paediatric Thyroid Carcinoma: The Genetic Revolution and Its Implications for Therapy and Outcomes

Background: The understanding of the molecular basis of paediatric thyroid carcinoma has expanded rapidly in the last decade. Most carcinomas are associated with de novo somatic gene alterations that confer distinct clinicopathological characteristics. In comparison to adults, paediatric carcinomas are less commonly associated with point mutations and more commonly with gene fusions, which are characterised by more-invasive disease. Cancer predisposition genes play an important role in a small percentage of tumours, and the family history and the recognition of other syndromic features are key to identifying these patients. Molecular testing platforms for clinical use have been developed and validated in adults, and their use is becoming established in the management of indeterminate thyroid nodules, where they significantly reduce the rates of diagnostic lobectomy. Paediatric data are more limited than adult data, and the role of molecular testing in paediatric thyroid carcinoma management is evolving. Methods: This review describes the current knowledge of molecular alterations in paediatric thyroid carcinomas, evidence supporting molecular testing in clinical practice, and future directions for research. Results and Conclusions: A molecular diagnosis enables the use of molecularly targeted therapies for children and adolescents with advanced or radioiodine-refractory disease. There is also great potential for molecular testing to improve the accuracy of the risk-stratification of paediatric thyroid nodules, reducing surgical intervention and complications without negatively impacting outcomes, and data to support such an approach are emerging.

Recent Advances in Diagnostics and Therapeutics for Paediatric Thyroid Cancer

PURPOSE OF REVIEW

Paediatric thyroid cancer management traditionally relied on extrapolation from adult data and, despite good survival outcomes, often involved extensive surgical approaches and radioactive iodine (RAI) therapy with potentially life-long complications. Increasing understanding of paediatric diagnostic techniques, molecular tumour drivers and targeted therapies will allow a more nuanced, disease-specific comprehensive model of care. This review summarises recent developments in paediatric thyroid cancer biology, diagnosis and models of care.

METHODS

Review of relevant literature from the last 5 years to inform a narrative summary by a multidisciplinary team of clinician experts in paediatric thyroid cancer management.

FINDINGS

Standardised risk scoring systems will likely improve the objectivity and accuracy of paediatric thyroid nodule risk stratification on ultrasound, but further studies are needed to validate these. Identification of somatic and germline gene variants is playing a rapidly increasing role in paediatric thyroid cancer diagnosis and planning of surgical approaches and neoadjuvant and adjuvant therapies. There is growing recognition that lobectomy may achieve comparable outcomes, with reduced risk of complications, to total thyroidectomy in patients with low-risk disease. Molecularly targeted therapies are now available for the management of advanced disease as an adjuvant, and likely neo-adjuvant, therapy for medical debulking of large tumours and resensitisation of RAI-resistant disease.

CONCLUSIONS

The management pathways for paediatric thyroid cancer are rapidly evolving due to the increasing availability of paediatric-specific data. As management options become more complex, interdisciplinary collaboration and shared decision-making are ever more important.

Multicenter Retrospective Analysis of Pediatric Differentiated Thyroid Carcinoma: Treatment Practices and Outcomes Prior to Pediatric American Thyroid Association Guidelines Implementation

BACKGROUND

Differentiated thyroid carcinoma (DTC) is the most common pediatric thyroid malignancy, with papillary thyroid carcinoma (PTC) representing 90% of the cases. In 2015, the American Thyroid Association (ATA) developed management guidelines for pediatric DTC.

PROCEDURE

Patients less than 21 years of age diagnosed with DTC between 2000 and 2015 at Texas Children's Hospital, Seattle Children's Hospital, Children's Healthcare of Atlanta, Children's Hospital Colorado, and Nationwide Children's Hospital were retrospectively analyzed to evaluate treatment practices before the implementation of the ATA guidelines.

RESULTS

We included 216 pediatric patients with DTC. A majority were female (76%) with a median age at diagnosis of 14.8 years. Neck swelling (56%) and palpable nodules (49%) were common presenting symptoms. Diagnostic evaluations typically included thyroid ultrasound, with common features being microcalcifications (47.7%) and hypoechogenicity (39.0%). Fine-needle aspiration cytology confirmed diagnosis in 50.5%. The majority of patients underwent total thyroidectomy (78.7%) and lymph node dissection (75.5%). ATA risk stratification was low, intermediate, and high risk in 111 (51.4%), 29 (13.4%), and 76 patients (35.2%), respectively. Upfront radioactive iodine (RAI) was administered in 83%. At 1-year follow-up, 46% were disease-free (66% low risk, 59% intermediate risk, and 13% high risk). The 5-year progression-free survival for low, intermediate, and high risk were 86%, 53%, and 43%, respectively. The disease-related overall survival was 100%.

CONCLUSIONS

Prior to the introduction of the ATA guidelines, a majority of patients underwent total thyroidectomy with lymph node dissection followed by RAI. Selective use of RAI for low-risk disease as recommended in the current guidelines may be appropriate.

Patients, parents and professional perspectives on molecular radiotherapy for neuroblastoma and paediatric neuroendocrine cancers

Treatment with radioactive drugs (molecular radiotherapy, MRT) is an option for selected children with neuroblastoma and neuroendocrine cancers. As few hospitals are appropriately equipped and staffed to provide paediatric MRT, many families have to travel long distances from home for prolonged periods. To improve professional understanding of the challenges faced by children receiving these treatments and their parents, and to help them appreciate the difficulties faced by professionals in delivering complex treatments, a meeting bringing together parents, patients and professionals was held. Ten people (five parents of children with neuroblastoma, two parents of children with neuroendocrine cancers, two adults who had received treatment for neuroendocrine cancers in childhood and one adult treated for neuroblastoma) gave personal perspectives of treatment with MRT. Three professionals from different disciplines involved with this treatment and research to improve its results gave their views on the administration of MRT, and how treatment outcomes might be improved. Fifteen people, including parents and professionals, contributed to the general discussion. Following the meeting, a questionnaire was circulated to those attending to capture their overall views, and any reflections they may have had after the meeting. Whilst many positive comments and compliments were received, this report focuses on the reported challenges and difficulties. The event is an example of meaningful Patient and Public Involvement and Engagement and has resulted in development of better information resources, strategies to mitigate inconveniences experienced and a standing group of advocates to advise on research design and acceptability.

Exploring the application of FNA-Tg for the diagnosis of cervical lymph node metastasis in PTC

BACKGROUND

Currently, fine-needle aspiration washout thyroglobulin (FNA-Tg) are mainly utilized to assist in the detection of lateral lymph node metastasis (LLNM) in papillary thyroid carcinoma (PTC). However, there is currently no clear definition of the method, procedure, and diagnostic value of FNA-Tg testing.

METHODS

Prospectively collected data from 215 PTC patients who underwent lateral neck LNs dissection in the 900th hospital from 2022 to 2024. A total of 249 suspicious lymph nodes were included and were categorized into a metastasis group (n = 176) and a non-metastasis group (n = 73) based on postoperative pathological findings.

RESULTS

Overall analysis revealed that FNA-Tg demonstrated superior diagnostic efficacy for LLNM in PTC compared to FNAC (area under the curve [AUC] = 0.950 versus 0.766). The optimal diagnostic thresholds were determined to be 16.45 μg/L for the primary LLNM group and 0.15 μg/L for the recurrent LLNM. Subgroup analysis indicated that a statistically significant difference in the diagnostic performance of FNA-Tg and FNAC for PTC LLNM was observed only when the LN short diameter was ≤0.8 cm (p < 0.001). Further more, when thyroglobulin antibody (TgAb) results were negative, the combination of the optimal threshold for FNA-Tg and the FNA-Tg/serum thyroglobulin (sTg) ratio was determined to be the most effective diagnostic criterion (criterion ③; AUC = 0.943).

CONCLUSION

FNA-Tg has a higher diagnostic value for PTC LLNM, especially in small LNs.

Automatic prediction of non-iodine-avid status in lung metastases for radioactive I131 treatment in differentiated thyroid cancer patients

Objectives

The growing incidence of differentiated thyroid cancer (DTC) have been linked to insulin resistance and metabolic syndrome. The imperative need for developing effective diagnostic imaging tools to predict the non-iodine-avid status of lung metastasis (LMs) in differentiated thyroid cancer (DTC) patients is underscored to prevent unnecessary radioactive iodine treatment (RAI).

Methods

Primary cohort consisted 1962 pretreated LMs of 496 consecutive DTC patients with pretreated initially diagnosed LMs who underwent chest CT and subsequent post-treatment radioiodine SPECT. After automatic lesion segmentation by SE V-Net, SE Net deep learning was trained to predict non-iodine-avid status of LMs. External validation cohort contained 123 pretreated LMs of 24 consecutive patients from other two hospitals. Stepwise validation was further performed according to the nodule's largest diameter.

Results

The SE-Net deep learning network yielded area under the receiver operating characteristic curve (AUC) values of 0.879 (95% confidence interval: 0.852-0.906) and 0.713 (95% confidence interval: 0.613-0.813) for internal and external validation. With the LM diameter decreasing from ≥10mm to ≤4mm, the AUCs remained relatively stable, for smallest nodules (≤4mm), the model yielded an AUC of 0.783. Decision curve analysis showed that most patients benefited using deep learning to decide radioactive I131 treatment.

Conclusion

This study presents a noninvasive, less radioactive and fully automatic approach that can facilitate suitable DTC patient selection for RAI therapy of LMs. Further prospective multicenter studies with larger study cohorts and related metabolic factors should address the possibility of comprehensive clinical transformation.

Predictive factors for lung metastasis in pediatric differentiated thyroid cancer: a clinical prediction study

OBJECTIVES

The objective of this study was to develop and evaluate the efficacy of a nomogram for predicting lung metastasis in pediatric differentiated thyroid cancer.

METHODS

The SEER database was utilized to collect a dataset consisting of 1,590 patients who were diagnosed between January 2000 and December 2019. This dataset was subsequently utilized for the purpose of constructing a predictive model. The model was constructed utilizing a multivariate logistic regression analysis, incorporating a combination of least absolute shrinkage feature selection and selection operator regression models. The differentiation and calibration of the model were assessed using the C-index, calibration plot, and ROC curve analysis, respectively. Internal validation was performed using a bootstrap validation technique.

RESULTS

The results of the study revealed that the nomogram incorporated several predictive variables, namely age, T staging, and positive nodes. The C-index had an excellent calibration value of 0.911 (95 % confidence interval: 0.876-0.946), and a notable C-index value of 0.884 was achieved during interval validation. The area under the ROC curve was determined to be 0.890, indicating its practicality and usefulness in this context.

CONCLUSIONS

This study has successfully developed a novel nomogram for predicting lung metastasis in children and adolescent patients diagnosed with thyroid cancer. Clinical decision-making can be enhanced by assessing clinicopathological variables that have a significant predictive value for the probability of lung metastasis in this particular population.

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.

Impact of lateral cervical lymph node metastasis on lung metastasis in pediatric thyroid cancer: A correlation study

BACKGROUND

Thyroid cancer (TC) frequently manifests with lung metastases in the pediatric population, occurring at a significant rate of 30 %. This study aims to evaluate the impact of regional patterns of cervical lymph node metastases on lung metastases in pediatric TC.

METHODS

Retrospective analysis was conducted on data from pediatric TC patients spanning the years 2000 to 2018. We compared the rates of lymph node metastasis (LNR), the number of lymph node metastases, and the number of dissected lymph nodes in the central and lateral cervical regions between patients with and without lung metastases. Statistical methods were employed to adjust for confounders during hypothesis testing.

RESULTS

A total of 227 pediatric patients, with a median age of 15.12 ± 2.84 years, were included in the study. Of these, 202 (89 %) exhibited LN metastasis, with 40(17.62 %) patients presenting with lung metastasis. Patients with lung metastases were found to be younger (13.40 ± 3.11 vs. 15.50 ± 2.64, p < 0.001), had larger primary tumor diameters (3.49 ± 1.98 vs. 2.31 ± 1.45, p < 0.001), and exhibited a higher number of lymph node metastases (23.40 ± 10.75 vs. 14.65 ± 13.16, p < 0.001). Notably, in patients with LN metastases, the presence of >12 lateral cervical lymph node metastases emerged as a significant risk factor for lung metastases. Among children with metachronous lung metastases, the median time to detection of lung metastases was 43 (12-132) months, and they appeared to receive a greater proportion of radioactive iodine (RAI) treatment compared to those with synchronous lung metastases.

CONCLUSION

Lateral cervical lymph node metastasis independently predicts the likelihood of lung metastases in pediatric TC. Furthermore, our findings emphasize the importance of thorough examination of the lungs during follow-up, particularly when the number of metastatic lateral cervical lymph nodes exceeds 12.

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

OBJECTIVE

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

STUDY DESIGN

Multicenter retrospective study of prospectively collected data.

SETTING

Tertiary referral center.

METHODS

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

RESULTS

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

CONCLUSION

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

Analysis of the clinical factors affecting excellent response of Iodine-131 treatment for pulmonary metastases from differentiated thyroid cancer

Background

Iodiene-131 (131I) treatment is the primary therapeutic approach for imaging 131I-avid pulmonary metastases. The response to radioiodine (RAI) treatment is an important prognostic factor in patients with pulmonary metastases from differentiated thyroid cancer (DTC). Patients who achieve an excellent response (ER) to 131I treatment show significantly reduced disease-related mortality. This study aimed to retrospectively analyse the clinical data and therapeutic effects of 131I treatment in patients with DTC and pulmonary metastases and to screen out the clinical factors affecting ER.

Materials and methods

The study included a total of 75 patients with exclusively Iodine-131 avid (131I-avid) pulmonary metastases who underwent 131I treatment. Relevant clinical data for these patients were collected. Following treatment, the status of DTC metastatic lesions was categorized as follows: excellent response (ER), biochemical incomplete response (BIR), structural incomplete response (SIR), or indeterminate response (IDR). Gender, age at diagnosis, pathological type, stages (TNM), stimulated thyroglobulin (sTg) value before initial 131I treatment, metastatic nodule size, and type of post-treatment whole body scan (Rx-WBS) were recorded. Mono-factor analysis and binary logistic regression analyses were used to identify the factors that might affect the ER in DTC pulmonary metastases. The receiver operating characteristic (ROC) curve of the sTg value was used to predict the ER of 131I treatment.

Results

All 75 patients with exclusively 131I-avid pulmonary metastases received 131I treatment and underwent follow-up. Out of the 75 patients, 26 achieved ER, resulting in an excellent response rate of 34.7 % (26/75). Among them, 25 (25/26, 96.2 %) achieved an ER after undergoing two rounds of 131I treatment. Binary logistic regression analysis showed that the factors influencing DTC pulmonary metastases excellent response were lower sTg levels [odds ratio (OR) = 0.998, P < 0.001], micronodular metastases (OR = 0.349, P = 0.001) and focal distribution on Rx-WBS imaging (OR = 0.113, P = 0.001). The area under the ROC curve for sTg value predicting ER was 0.876, and the cut-off value was 26.84 ng/mL, with a sensitivity and specificity of 87.9 % and 80.3 %, respectively.

Conclusions

131I treatment is effective for 131I-avid pulmonary metastases of DTC. Some patients who underwent 131I treatment achieved ER. Most patients with ER were obtained after two rounds of 131I treatments. Patients with sTg values before initial 131I treatment lower than 26.84 ng/mL, micronodular metastases, and focal distribution on Rx-WBS imaging were more likely to achieve ER.

Predictive risk factors for distant metastasis in pediatric differentiated thyroid cancer from Saudi Arabia

BACKGROUND

Despite their excellent prognosis, children and young adults (CAYA) with differentiated thyroid cancer (DTC) tend to have more frequent occurrence of distant metastasis (DM) compared to adult DTC. Data about DM in CAYA from Middle Eastern ethnicity is limited.

METHODS

Medical records of 170 patients with DTC ≤18 years were retrospectively reviewed. Clinico-pathological factors associated with lung metastasis in CAYA, their clinical presentation and outcome were analyzed. Rick factors related to distant metastasis-free survival (DMFS) for the whole cohort were evaluated.

RESULTS

DM was observed in 27 patients and all were lung metastasis. Lung metastasis was significantly associated with younger age (≤15 years), extrathyroidal extension (ETE), multifocal tumors, bilaterality, presence of lymph node (LN) disease and high post-operative stimulated thyroglobulin (sTg). Highest negative predictive values were seen with low post-operative sTg (97.9%), absence of LN disease (93.8%), absence of ETE (92.2%) and age older than 15 years (92.9%). Post-therapy whole body scan (WBS) identified most of the lung metastasis (21 of 27; 77.8%). Upon evaluating patients response according to ATA guidelines, excellent response was seen in only one patient, while biochemical persistence and structural persistence were seen in 11.1% (3/27) and 77.8% (21/27), respectively. Elevated post-operative sTg (>10ng/ml) was the only risk factor found to be significantly associated with both biochemical persistence (with or without structural persistence (p = 0.0143)) and structural persistence (p = 0.0433). Cox regression analysis identified age and post-operative sTg as independent risk factors related to DMFS. Based on these two risk factors for DMFS, patients were divided into 3 groups: low risk (no risk factors), intermediate risk (1 risk factor) and high risk (both risk factors). 20-year DMFS rates in the low-, intermediate- and high-risk groups were 100.0%, 81.3% and 23.7% respectively (p < 0.0001).

CONCLUSION

Higher suspicion for metastatic pediatric DTC should be considered in patients who are young, have LN disease, extrathyroidal extension and elevated post-operative sTg. Persistent disease, despite therapy, is very common and it appears to be related to post-operative sTg level. Hence, risk adaptive management is desirable in CAYA with DTC.

Children's Oncology Group's 2023 blueprint for research: Rare tumors

The Children's Oncology Group (COG) Rare Tumor Committee includes the Infrequent Tumor and Retinoblastoma subcommittees, encompassing a wide range of extracranial solid tumors that do not fall within another COG disease committee. Current therapeutic trial development focuses on nasopharyngeal carcinoma, adrenocortical carcinoma, pleuropulmonary blastoma, colorectal carcinoma, melanoma, and thyroid carcinoma. Given the rarity of these tumors, novel strategies and international collaborative efforts are necessary to advance research and improve outcomes.

The association between the interval of radioiodine treatment and treatment response, and side effects in patients with lung metastases from differentiated thyroid cancer

Objective

Repeat radioiodine (RAI) treatment has been widely implemented for RAI-avid lung metastases and is clinically effective for lung metastatic differentiated thyroid cancer (DTC). We aim to investigate the association between the interval of RAI treatment and short-term response, and the side effects in patients with lung metastases from DTC and to identify predictors for non-effective response to the next RAI treatment.

Methods

A total of 282 course pairs from 91 patients were established and categorized into two groups by the interval of neighboring RAI treatment (<12 and ≥12 months), and the characteristics and treatment response between the two groups were compared. Multivariate logistic regression was used to identify predictors associated with treatment response. The side effects in the former course and the latter course were compared while taking into account the interval.

Results

No significant difference was found between the two groups in treatment response in the latter course (p > 0.05). In the multivariate analysis, age ≥ 55 years (OR = 7.29, 95% CI = 1.66-33.35, p = 0.008), follicular thyroid cancer (OR = 5.00, 95% CI = 1.23-22.18, p = 0.027), and a second RAI treatment as the former course (OR = 4.77, 95% CI = 1.42-18.61, p = 0.016) were significantly associated with a non-effective response. There was no significant difference in the side effects in the former and latter courses between the two groups (p > 0.05).

Conclusion

The interval of RAI treatment does not affect short-term response and side effects of DTC patients with RAI-avid lung metastases. It was feasible to defer repeat evaluation and treatment with an interval of at least 12 months to obtain an effective response and reduce the risk of side effects.

Prepubertal Children with Papillary Thyroid Carcinoma Present with More Invasive Disease Than Adolescents and Young Adults

Introduction: Pediatric papillary thyroid carcinomas (PTCs) are more invasive than adult PTCs. No large, contemporary cohort study has been conducted to determine whether younger children are at higher risk for advanced disease at presentation compared to adolescents. We aimed to describe pediatric PTC and contextualize its characteristics with a young adult comparison cohort. Methods: The National Cancer Database was interrogated for pediatric and young adult PTCs diagnosed between 2004 and 2017. Clinical variables were compared between prepubertal (≤10 years old), adolescent (11-18 years old), and young adult (19-39 years old) groups. Multivariable logistic regression modeling for independent predictors of metastases was conducted. A subanalysis of microcarcinomas (size ≤10 mm) was performed. Results: A total of 4860 pediatric (prepubertal n = 274, adolescents n = 4586) and 101,159 young adult patients were included. Prepubertal patients presented with more extensive burden of disease, including significantly larger primary tumors, higher prevalence of nodal and distant metastases, and increased frequency of features such as lymphovascular invasion, and extrathyroidal extension (ETE). Prepubertal age was an independent predictor of positive regional nodes (adjusted odds ratio [AOR] = 1.36 [95% confidence interval {CI} 1.01-1.84], p = 0.04) and distant metastatic disease (AOR = 3.12 [CI 1.96-4.96], p < 0.001). However, there was no difference in survival between groups (p = 0.32). Prepubertal age independently predicted lymph node metastases for microcarcinomas (AOR = 2.19 [CI 1.10-4.36], p = 0.03). Prepubertal (n = 41) versus adolescent (n = 937) patient age was associated with gross ETE (p = 0.004), even with primary tumors ≤1 cm in size. Conclusions: Patients aged <11 years old present with more advanced disease than adolescents, with a higher likelihood of nodal and distant metastatic disease at time of diagnosis, although survival is high. Prepubertal children undergo more extensive treatment, likely reflective of more invasive disease at the outset, even in the setting of a subcentimeter primary tumor.

Prognostic value of 12-month response to therapy in pediatric patients with differentiated thyroid cancer

PURPOSE

In pediatric patients with differentiated thyroid cancer (DTC) we assessed the prognostic value of the 12-month response to therapy after initial treatment with surgery and radioactive iodine (RAI).

METHODS

We retrospectively evaluated 94 pediatric patients with DTC, treated with surgery and RAI who were initially classified as low, intermediate or high risk of relapse of disease according to the American Thyroid Association (ATA) guidelines. Twelve months after RAI administration the response to therapy was assessed by serum thyroglobulin (Tg) measurement and neck ultrasound and patients were classified as having excellent response (ER) or no-ER.

RESULTS

At the 12 months evaluation, 62 (66%) patients had ER and 32 (34%) no-ER. During a mean follow-up time of 86 months (range 9-517), 19 events occurred (20% cumulative event rate). Events occurred more frequently in younger patients (p < 0.05), in those at ATA intermediate/high risk (p < 0.01) and with a pre-RAI therapy Tg level > 10 ng/mL (p < 0.001), and in those with no-ER (p < 0.001). At multivariate analysis, the evidence of no-ER was the only independent predictor of events.

CONCLUSION

In pediatric patients with DTC, the response to therapy evaluated 12 months after initial treatment has an independent prognostic impact and is able to predict mid-term outcome. Patients with no-ER at 12 months after RAI therapy should be closely followed-up.

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

CONTEXT

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Pediatric thyroid cancer: Recent developments

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

Health-Related Quality of Life at Diagnosis for Pediatric Thyroid Cancer Patients

CONTEXT

Pediatric thyroid cancer (TC) incidence rates are increasing, yet TC has one of the highest survival rates. Despite increased prevalence, little is known about youth adjustment to TC, particularly compared to other pediatric cancers.

OBJECTIVE

The current study sought to describe health-related quality of life (HRQoL) in pediatric TC patients early after diagnosis compared to other pediatric cancer patients and healthy youth and examine predictors of HRQoL.

DESIGN

Patients completed psychosocial questionnaires as part of a clinic-based screening program around time of surgery. TC HRQoL was compared to other pediatric cancer and healthy youth reported norms. Clinical and demographic data extracted from the medical record were examined for predictors of HRQoL.

SETTING

Pediatric Thyroid Center.

PATIENTS AND OTHER PARTICIPANTS

Pediatric TC patients (ages 8.5-23.4 years) and their caregivers.

MAIN OUTCOME MEASURES

Pediatric Quality of Life Inventory (HRQoL) and distress thermometer.

RESULTS

Findings evidenced significantly higher HRQoL for TC patients than other pediatric cancers for all but emotional and school functioning. Compared to healthy youth, TC patients reported significantly lower functioning, except comparable social functioning. No significant differences in HRQoL were identified based on disease severity, thyroid disease history, or treatment. Patient distress was associated with HRQoL.

CONCLUSIONS

The findings suggest general resilience in TC patients compared to youth with other cancers, yet worse HRQoL than peers. Early universal screening is warranted due to a short TC treatment regimen. If administrative barriers preclude comprehensive screening, the single-item distress thermometer may identify patients for further comprehensive screening.

Risk Factors for Pulmonary Metastasis in Differentiated Thyroid Carcinoma Patients and the Significance of Changes in Matrix Metalloproteinase 13 and microRNA-142 Levels

This work aims to explore the risk factors of lung metastasis (LM) in differentiated thyroid cancer (DTC) (LM-DTC) and the effect of treatment and to detect the relationship between LM-DTC and the levels of matrix metalloproteinase-13 (MMP-13) and micro ribonucleic acid (RNA)-142 (miR-142) in peripheral blood. The data of 420 patients with DTC who are admitted from March 2020 to December 2021 are collected and divided into a non-metastasis group (non-LM group) of 400 cases and metastasis group (LM group) of 20 cases according whether the mung metastasis is found. In addition, risk factors of LM-DTC are analysed and compared. The results of multivariate logistic analysis show that age, disease course, and imaging timing are independent influencing factors of the radionuclide treatment effect. Follicular carcinoma, abnormal expressions of MMP-13, and miR-142 can increase the risk of LM-DTC. MMP-13 and miR-142 can be undertaken as auxiliary diagnostic biological indicators.

Nomogram individually predicts the risk for distant metastasis and prognosis value in female differentiated thyroid cancer patients: A SEER-based study

Objective

Distant metastasis (DM) is an important prognostic factor in differentiated thyroid cancer (DTC) and determines the course of treatment. This study aimed to establish a predictive nomogram model that could individually estimate the risk of DM and analyze the prognosis of female DTC patients (FDTCs).

Materials and methods

A total of 26,998 FDTCs were retrospectively searched from the Surveillance, Epidemiology, and End Results (SEER) database from 2010 to 2018 and randomly divided into validation and training cohorts. Univariate and multivariate analyses were performed to screen for prognostic factors and construct a prediction nomogram. The performance of the nomogram was assessed by the area under the receiver operating characteristic curve (AUC), concordance index (C-index), and a calibration curve. The overall survival (OS) and cancer-specific survival (CSS) were evaluated by Kaplan-Meier (K-M) analysis.

Results

A total of 263 (0.97%) FDTCs were reported to have DM. K-M analysis showed the association of multiple-organ metastases and brain involvement with lower survival rates (P < 0.001) in patients. Tumor size, age at diagnosis, thyroidectomy, N1 stage, T3-4 stage, and pathological type were independent predictive factors of DM in FDTCs (all P < 0.001). Similarly, age at diagnosis, Black, DM, T3-4 stage, thyroidectomy, and lung metastasis were determined as independent prognostic factors for FDTCs (all P < 0.001). Several predictive nomograms were established based on the above factors. The C-index, AUC, and calibration curves demonstrated a good performance of these nomogram models.

Conclusion

Our study was successful in establishing and validating nomograms that could predict DM, as well as CSS and OS in individual patients with FDTC based on a large study cohort. These nomograms could enable surgeons to perform individualized survival evaluation and risk stratification for FDTCs.

A Predictive Model for the 10-year Overall Survival Status of Patients With Distant Metastases From Differentiated Thyroid Cancer Using XGBoost Algorithm-A Population-Based Analysis

Purpose: To explore clinical and non-clinical characteristics affecting the prognosis of patients with differentiated thyroid cancer with distant metastasis (DTCDM) and establish an accurate overall survival (OS) prognostic model.

Patients and methods: Study subjects and related information were obtained from the National Cancer Institute’s surveillance, epidemiology, and results database (SEER). Kaplan‐Meier analysis, log-rank test, and univariate and multivariate Cox analysis were used to screen for factors influencing the OS of patients with DTCDM. Nine variables were introduced to build a machine learning (ML) model, receiver operating characteristic (ROC) was used to evaluate the recognition ability of the model, calibration plots were used to obtain prediction accuracy, and decision curve analysis (DCA) was used to estimate clinical benefit.

Results: After applying the inclusion and exclusion criteria, a total of 3,060 patients with DTCDM were included in the survival analysis from 2004 to 2017. A machine learning prediction model was developed with nine variables: age at diagnosis, gender, race, tumor size, histology, regional lymph node metastasis, primary site surgery, radiotherapy, and chemotherapy. After excluding patients who survived <120 months, variables were sub-coded and machine learning was used to model OS prognosis in patients with DTCDM. Patients 6–50 years of age had the highest scores in the model. Other variables with high scores included small tumor size, male sex, and age 51–76. The AUC and calibration curves confirm that the XGBoost model has good performance. DCA shows that our model can be used to support clinical decision-making in a 10-years overall survival model.

Conclusion: An artificial intelligence model was constructed using the XGBoost algorithms to predict the 10-years overall survival rate of patients with DTCDM. After model validation and evaluation, the model had good discriminative ability and high clinical value. This model could serve as a clinical tool to help inform treatment decisions for patients with DTCDM.

A Predictive Model to Differentiate Between Second Primary Lung Cancers and Pulmonary Metastasis

RATIONALE AND OBJECTIVES

To develop and validate a nomogram for differentiating second primary lung cancers (SPLCs) from pulmonary metastases (PMs).

MATERIALS AND METHODS

A total of 261 lesions from 253 eligible patients were included in this study. Among them, 195 lesions (87 SPLCs and 108 PMs) were used in the training cohort to establish the diagnostic model. Twenty-one clinical or imaging features were used to derive the model. Sixty-six lesions (32 SPLCs and 34 PMs) were included in the validation set.

RESULTS

After analysis, age, lesion distribution, type of lesion, air bronchogram, contour, spiculation, and vessel convergence sign were considered to be significant variables for distinguishing SPLCs from PMs. Subsequently, these variables were selected to establish a nomogram. The model showed good distinction in the training set (area under the curve = 0.97) and the validation set (area under the curve = 0.92).

CONCLUSION

This study found that the nomogram calculated from clinical and radiological characteristics could accurately classify SPLCs and PMs.

Diverse Oncogenic Fusions and Distinct Gene Expression Patterns Define the Genomic Landscape of Pediatric Papillary Thyroid Carcinoma

Pediatric papillary thyroid carcinoma (PPTC) is clinically distinct from adult-onset disease. Although there are higher rates of metastasis and recurrence in PPTC, prognosis remains highly favorable. Molecular characterization of PPTC has been lacking. Historically, only 40% to 50% of childhood papillary thyroid carcinoma (PTC) were known to be driven by genomic variants common to adult PTC; oncogenic drivers in the remainder were unknown. This contrasts with approximately 90% of adult PTC driven by a discrete number of variants. In this study, 52 PPTCs underwent candidate gene testing, followed in a subset by whole-exome and transcriptome sequencing. Within these samples, candidate gene testing identified variants in 31 (60%) tumors, while exome and transcriptome sequencing identified oncogenic variants in 19 of 21 (90%) remaining tumors. The latter were enriched for oncogenic fusions, with 11 nonrecurrent fusion transcripts, including two previously undescribed fusions, STRN-RET and TG-PBF. Most fusions were associated with 3' receptor tyrosine kinase (RTK) moieties: RET, MET, ALK, and NTRK3. For advanced (distally metastatic) tumors, a driver variant was described in 91%. Gene expression analysis defined three clusters that demonstrated distinct expression of genes involved in thyroid differentiation and MAPK signaling. Among RET-CCDC6-driven tumors, gene expression in pediatric tumors was distinguishable from that in adults. Collectively, these results show that the genomic landscape of pediatric PTC is different from adult PTC. Moreover, they identify genomic drivers in 98% of PPTCs, predominantly oncogenic fusion transcripts involving RTKs, with a pronounced impact on gene expression. Notably, most advanced tumors were driven by a variant for which targeted systemic therapy exists. SIGNIFICANCE: This study highlights important distinctions between the genomes and transcriptomes of pediatric and adult papillary thyroid carcinoma, with implications for understanding the biology, diagnosis, and treatment of advanced disease in children.

Oncogene-specific inhibition in the treatment of advanced pediatric thyroid cancer

Papillary thyroid cancer (PTC) is the most common form of differentiated thyroid cancer in the pediatric population and represents the second most common malignancy in adolescent females. Historically, PTC has been classified on the basis of histology, however, accumulating data indicate that molecular subtyping based on somatic oncogenic alterations along with gene expression profiling can better predict clinical behavior and may provide opportunities to incorporate oncogene-specific inhibitory therapy to improve the response to radioactive iodine (RAI). In this issue of the JCI, Y.A. Lee, H. Lee, and colleagues showed that oncogenic fusions were more commonly associated with invasive disease, increased expression of MAPK signaling pathway genes (ERK score), and decreased expression of the sodium-iodine symporter, which was restored by RET- and NTRK-inhibitory therapy. These findings lend credence to the idea of reclassifying pediatric thyroid cancers using a three-tiered system, rather than the two-tiered adult system, and open avenues for the treatment of progressive, RAI-refractory PTC in patients.

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

CONTEXT

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

High Incidence of Distant Metastasis Is Associated With Histopathological Subtype of Pediatric Papillary Thyroid Cancer - a Retrospective Analysis Based on SEER

OBJECTIVE

Children with papillary thyroid cancer (PTC) have a higher invasive rate and distant metastasis rate, but the mortality rate is lower with unknown reasons. The majority of PTC cases comprise classical papillary thyroid carcinoma (CPTC) and follicular variant papillary thyroid carcinoma (FVPTC). This study aimed to determine the relationship between histopathological subtype and rate of distant metastasis and investigate factors influencing distant metastasis in pediatric PTC.

METHODS

A total of 102,981 PTC patients were recruited from SEER registry, 2004-2015. Proportion of distant metastasis between children (≤18 years) and adults with different histopathological subtypes was compared by propensity score matching. The cut-off age for distant metastasis in children was calculated by receiver operating characteristic (ROC) curve, and the risk factors for distant metastasis in pediatric patients were analyzed by logistic regression models.

RESULTS

Among the 1,484 children and 101,497 adults included in the study, the incidence of CPTC patients with distant metastasis in children was higher than that in adults (p<0.001). The ROC curve was calculated, which yielded a cut-off age for distant metastasis in CPTC children as 16 years old. In CPTC, the proportion of young children (2-16 years) with distant metastasis was higher than that of adolescents (17-18 years) and adults (>18 years) (both p<0.001). While there was no such trend in FVPTC. In young children (2-16 years), the incidence of CPTC with distant metastasis was higher than FVPTC (p=0.006). There was no difference between the proportion of CPTC and FVPTC with distant metastasis in adolescents (17-18 years) and adults. Logistic regression models revealed that extrathyroidal extension, lymph node metastasis and CPTC histopathological subtype were risk factors for distant metastasis in young children aged 2 -16 years.

CONCLUSIONS

In CPTC, the incidence of distant metastasis in young children (2-16 years) was significantly higher than that in adolescents (17-18 years) and adults (>18 years). In patients with distant metastasis aged 2-16 years, the proportion of CPTC was higer than that of FVPTC. Extrathyroidal extension, lymph node metastasis, and CPTC histopathological subtype were risk factors for distant metastasis in young children aged 2-16 years.