Differentiated thyroid cancer

Radioiodine Therapy in Pediatric Differentiated Thyroid Cancer: Dosimetry, Clinical Care, and Future Challenges

ABSTRACT

Thyroid cancer is very rare in children. 131 I therapy after thyroidectomy is established in pediatric differentiated thyroid cancer (DTC). Pediatric DTC guideline is silent on the optimum amount of 131 I that could be safely and effectively administered to children who are more radiosensitive. Like adult DTC, children are also given 131 I therapy empirically based either on age or body weight. Pediatric DTC guideline recommends that patient-specific dosimetry is important in children. Still, due to the low incidence rate and the practical difficulties of dosimetry, it has neither been established nor adopted in routine practice. This review article aims to discuss current approaches of 131 I therapy in children and young adult patients with DTC and dosimetric data obtained by several investigators. Efforts are required to simplify dosimetric procedures and precise results, especially in determining lesion size. We prefer 3-dimensional dosimetry over planar dosimetry, where lesion size could be measured accurately. 124 I PET/CT-based dosimetry is expected to give accurate dosimetric results. The most challenging aspect is that no randomized controlled trials are available to compare the empiric 131 I therapy results versus dosimetry-based treatment outcomes in children and young adults. Suppose dosimetry-based 131 I therapy could be shown to have better outcomes, namely, successful ablation rate, better disease-free survival, and lesser treatment-emergent adverse events than empirical 131 I treatment. In that case, one can argue in favor of the former. Unfortunately, no convincing study is currently available. Thus, there is a need for a randomized control trial to settle this issue.

Molecular Landscape of Pediatric Thyroid Cancer: A Review

Thyroid carcinomas (TC) are rare in the pediatric population; however, they constitute the most common endocrine malignancy. Despite some similarities with adult carcinomas, they have distinct clinical behavior and responses to therapy due to their unique pathology and molecular characteristics. The age cut-off used for defining the pediatric age group has been variable across different studies, and the universally accepted recommendations influence accurate interpretation of the available data. Moreover, factors such as radiation exposure and germline mutations have greater impact in children than in adults. Papillary TC is the most common and the most evaluated pediatric TC. Others, including follicular, poorly differentiated and medullary carcinomas, are rarer and have limited available literature. Most studies are from the West. Asian studies are primarily from Japan, with few from China, India, Saudi Arabia and Republic of Korea. This review provides a comprehensive account of the well-established and novel biomarkers in the field, including point mutations, fusions, miRNA, and thyroid differentiation genes. Familial and syndromic associations are also discussed. Current management guidelines for pediatric patients are largely derived from those for adults. An awareness of the molecular landscape is essential to acknowledge the uniqueness of these tumors and establish specific diagnostic and therapeutic guidelines.

Applicability of Adults 2015 American Thyroid Association Differentiated Thyroid Cancer Guidelines for Postoperative Risk Stratification and Postradioiodine Treatment Dynamic Risk Stratification in Pediatric Population

Purpose  This retrospective study aimed to study the applicability of 2015 adult American Thyroid Association (ATA) differentiated thyroid cancer (DTC) postoperative risk stratification and guidelines in the pediatric population for evaluating the number of metastatic lymph nodes in the postoperative risk stratification and postradioactive iodine (RAI) treatment dynamic risk stratification (DRS) using response to treatment (RTT) reclassification. In addition, the effect of pubertal status and gender was assessed on disease presentation and prognosis.

Methods  Data of 63 DTC patients aged 20 years or less, stratified into prepubertal, pubertal, and postpubertal age groups, was divided into low, intermediate, and high-risk groups using pediatric ATA recurrence risk stratification. Forty-seven patients were classified as responders (excellent and indeterminate responses) and incomplete responders (biochemical and structurally incomplete responses) by assessing the RTT at 1.5 years follow-up similar to recommendation of 2015 adult DTC ATA guidelines.

Results  Female-to-male ratio showed a trend of gradual increase with increasing age. Significantly more responders were observed in low- and intermediate-risk groups than in high-risk group ( p  = 0.0013; p  = 0.017, respectively), while prepubertal group had more extensive (N1b) disease. Using DRS at follow-up of 1.5 year, pubertal and postpubertal groups showed significantly better response to RAI. More female than male patients showed response and took significantly less time to respond to RAI ( p  = 0.003).

Conclusion  RAI response in pediatric DTC depends on pubertal status, gender, and number of malignant nodes. DRS using RTT classification may be applicable early at 1.5 years after initial therapy in different pubertal age and risk groups.

Factors Influencing Cervical Lymph Node Metastasis in Pediatric Differentiated Thyroid Cancers

Lymph node metastasis is a considerable variable influencing postoperative American Thyroid Association (ATA) risk stratification in pediatric differentiated thyroid cancer (DTC). The primary aim of this study was to ascertain the factors predicting nodal metastasis and describe the outcomes in relation to the ATA risk. Patients 18 years or younger operated between December 2005 and December 2019 were analyzed. Demographic, clinicopathological, treatment, and outcome data were recorded. Factors associated with nodal metastasis were assessed by univariate and multivariate regression analysis. Patients were stratified into low-, intermediate-, and high-risk as per the pediatric ATA guidelines. A total of 86 patients (43% male; median [IQR] age, 12 (10-14) years) underwent surgery during the study period. Lymph node metastases were present in 70 (82.4%) patients involving the lateral (8%) and central compartment (4.7%) alone and both (88.6%) compartments. Extrathyroid extension (ETE) was present in 65%; 35%, minimal; and 30%, extensive. On univariate analysis, nodal metastasis was more frequent in male patients, multifocal tumor, lymphovascular invasion, and ETE. On multivariate analysis, only ETE was predictive of nodal disease with an odds ratio of 8. Minimal and extensive ETEs were both significantly associated with lymph node metastases when compared to the absence of ETE. The 5-year disease-free survival was 100%, 95.7%, and 66% in the low-, intermediate-, and high-risk groups respectively (p < 0.0001). Pediatric DTCs have an exceptionally high incidence of lymph node metastasis. ETE is the single most important predictor of nodal disease. The ATA pediatric risk stratification is useful in predicting clinical outcomes.

Curcumin inhibits the viability, migration and invasion of papillary thyroid cancer cells by regulating the miR-301a-3p/STAT3 axis

Thyroid cancer is one of the most common malignant tumors, and the mortality rate associated with thyroid cancer has been increasing annually. Curcumin has been reported to exert an antitumor effect on papillary thyroid cancer (PTC), and the identification of additional mechanisms underlying the anticancer effect of curcumin on PTC requires further investigation. The present study aimed to explore the effects of curcumin on the viability, migration and invasion of PTC cells. TPC-1 cells were incubated with different concentrations of curcumin, and then, cell viability, migration and invasion, and wound healing were examined by CCK-8, Transwell and wound healing assays, respectively. Subsequently, microRNA (miR)-301a-3p mimics, miR-301a-3p inhibitors and signal transducer and activator of transcription (STAT)3 overexpression vector were transfected into TPC-1 cells, and cell viability, migration, and invasion were reassessed in these transfected cells. Matrix metallopeptidase (MMP)-2, MMP-9, epithelial-mesenchymal transition (EMT)-related markers, and Janus kinase (JAK)/STAT signaling pathway components were assessed by western blot analysis. Curcumin significantly inhibited cell viability, migration and invasion and downregulated MMP-2, MMP-9 and EMT marker expression. Additionally, curcumin decreased STAT3 expression by upregulating miR-301a-3p expression, and the inhibition of miR-301a-3p and the overexpression of STAT3 reversed the effects of curcumin on cell viability, migration and invasion, and MMP-2, MMP-9 and EMT marker expression in TPC-1 cells. Furthermore, curcumin suppressed the JAK/STAT signaling pathway through the miR-301a-3p/STAT3 axis. The data of the present study indicated that curcumin could inhibit the viability, migration and invasion of TPC-1 cells by regulating the miR-301a-3p/STAT3 axis. These findings may provide a possible strategy for the clinical treatment of PTC.

BRAF V600E and TERT promoter mutations in paediatric and young adult papillary thyroid cancer and clinicopathological correlation

Objectives The primary objective of this study was to determine the prevalence of BRAF V600E and TERTpromoter mutations in paediatric and young adult patients with papillary thyroid carcinoma (PTC) and the secondary objective, to assess their association with clinicopathological features. Methods Patients ≤20 years who underwent surgery for differentiated thyroid cancer (DTC) from 2005 to 2018 were consecutively enrolled for BRAF V600E and TERTpromoter mutations analysis and records analysed for the association of aggressive features. Univariate analysis and multivariate logistic regression were used to identify the independent predictors of BRAF V600E mutations. Results Among 100 patients with DTC, 68 patients were ≤18 years and the remaining 30 patients were >18 years of age with a median age of 17 years (IQR 14-19 years) 98 patients had PTC and 2 had FTC. BRAF V600E mutation was present in 14/98 (14.3%) PTC and TERTpromoter mutation noted in none. Multivariate analysis identified RAI refractoriness (OR:10.57, 95% CI: 2.6 to 41.6, P-0.0008) as an independent factor associated with BRAF V600E mutation. 17 patients with distant metastases were negative for both BRAF V600E or TERTpromoter mutation. No significant association was observed between age, gender, PTC variants, extra-thyroidal extension, lymphovascular invasion, multifocality, RAI administration and event rate with BRAF V600E mutation. Irrespective of BRAF V600E mutation, radioiodine refractory status (p-0.0001) had a reduced EFS probability. Conclusion In paediatric & young adult PTC, TERTpromoter mutation is absent and BRAFV600E mutation is not associated with distant metastasis. The prevalence rate of the BRAF V600E mutation is much lower compared to adult PTC patients.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Thyroid Cancer in the Pediatric Population

Thyroid cancer is rare in the pediatric population, but thyroid carcinomas occurring in children carry a unique set of clinical, pathologic, and molecular characteristics. In comparison to adults, children more often present with aggressive, advanced stage disease. This is at least in part due to the underlying biologic and molecular differences between pediatric and adult thyroid cancer. Specifically, papillary thyroid carcinoma (which accounts for approximately 90% of pediatric thyroid cancer) has a high rate of gene fusions which influence the histologic subtypes encountered in pediatric thyroid tumors, are associated with more extensive extrathyroidal disease, and offer unique options for targeted medical therapies. Differences are also seen in pediatric follicular thyroid cancer, although there are few studies of non-papillary pediatric thyroid tumors published in the literature due to their rarity, and in medullary carcinoma, which is most frequently diagnosed in the pediatric population in the setting of prophylactic thyroidectomies for known multiple endocrine neoplasia syndromes. The overall shift in the spectrum of histotypes and underlying molecular alterations common in pediatric thyroid cancer is important to recognize as it may directly influence diagnostic test selection and therapeutic recommendations.

Efficacy and Affecting Factors of 131I Thyroid Remnant Ablation After Surgical Treatment of Differentiated Thyroid Carcinoma

Purpose: Radioiodine (¹³¹I) thyroid remnant ablation is an important treatment of differentiated thyroid carcinoma (DTC) and various factors affecting its efficacy have been reported but not well defined. The aim of our study was to evaluate the efficacy and the affecting factors of ¹³¹I ablation after total or near-total thyroidectomy in a relative large DTC cohort. Methods: 261 DTC patients with negative thyroglobulin antibody received 100-200 mCi ¹³¹I for thyroid remnant ablation after total or near-total thyroidectomy between January 2012 and October 2015 in our hospital. The efficacy and affecting factors of ¹³¹I ablation therapy were retrospectively investigated. Results: The success rate of the first ¹³¹I thyroid remnant ablation was 65.90%. Univariate analysis demonstrated that larger tumor size, higher level of pre-ablation stimulated thyroglobulin (sTg), intermediate to high risk stratification for recurrence, and lymph node and distant metastases were associated with a lower success rate of the first ¹³¹I ablation (all p < 0.05). Multivariate logistic regression analysis showed that tumor size, pre-ablation sTg, and lymph node and distant metastases were independent factors affecting the efficacy of the first ¹³¹I ablation. Areas under receiver operating characteristic curves for sTg, sTg/TSH ratio, and tumor size to predict unsuccessful ablation were 0.831, 0.824, and 0.648, respectively. The threshold values were 4.595 ng/ml, 0.046 mg/IU, and 1.350 cm, respectively. The sensitivities were 95.51, 96.63, and 73.03% and the specificities were 64.54, 61.63, and 49.41%, respectively. The excellent response (ER) ratio of the successful group was significantly higher than that of the unsuccessful group. Conclusions: The efficacy of the first ¹³¹I thyroid remnant ablation after surgical treatment of DTC is well demonstrated, and tumor size, pre-ablation sTg, lymph node, and distant metastases are independent factors affecting its efficacy.

Thyroid Cancer in Pediatrics

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

Management Guidelines for Children with Thyroid Nodules and Differentiated Thyroid Cancer

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Pediatric thyroid cancers: an Indian perspective

Pediatric thyroid cancer is a rare entity accounting for less than 5% of all thyroid cancers. This intriguing disease is characterized by advanced presentation, coupled with frequent lymph nodal metastases and often pulmonary metastases. It perhaps exhibits a distinct biology and behaviour, because in spite of its aggressiveness, survival is extremely good. This mandates meticulous treatment decisions that are well executed, because the complications of therapy in patients with good survival may spell prolonged morbidity. Being an unusual disease, it is unlikely that level I evidence guiding the management will come forth. There have been controversies regarding management, and the current consensus comes from large prospective studies. There have been only a few studies from India detailing pediatric thyroid cancers. In the current discussion, we review the existing evidence about pediatric thyroid cancers, and try to have an Indian perspective at the problem.

Non-hematological tumors of head and neck region in the pediatric age group in a tertiary care cancer center

PURPOSE

To analyze the clinical profile, management and outcome of non-hematological tumors in head and neck region in children less than 18 years of age.

PATIENTS AND METHODS

Medical records of patients (0-18 years) presenting with non-hematological tumors of head and neck region from 2000 to 2010 were reviewed.

RESULT

Out of the 78 patients identified, 50 were males with median age of 14 years (3 months to 18 years). Histologically, 58 out of the 78 patients had malignant tumors and 20 were metastatic at presentation. Common site of tumor origin was noted as thyroid (23/78), salivary glands (21/78) and nasopharynx (13/78). Out of 78 patients, 44 patients were treated by surgery, 26 patients received radiation and 13 patients received chemotherapy, while 9 patients received radio-iodine (I-131) treatment. Median follow up of all cases was 22 months (range 1 month to 8 years). The event free survival was 74.1% and overall survival was 89.6%. Subset analysis revealed patients with thyroid and salivary gland malignancies have excellent survival, while those with squamous cell carcinoma and high risk neuroblastoma had poor outcome.

CONCLUSION

This study reveals the interesting profile of head and neck tumors in children, and important role of surgery for favorable outcome.

Thyroid cancer epidemiology and prognostic variables

Thyroid cancer comprises a broad spectrum of diseases with variable prognoses. Although most patients with this disease have excellent overall survival, there are some who do not fare so well. With the worldwide increase in incidence, the need to identify which tumours pose the greatest risk to patients is more acute than ever. This paper will discuss this rising trend in incidence with an analysis of the possible reasons for the increase. In addition, the paper will explore the factors that portend a worse prognosis for the individual patient. Finally, the limitations of the current staging systems will be discussed, with particular emphasis on why they are not as informative in the management of patients with thyroid cancer.

Thyroid papillary carcinoma in a 3-year-old American boy with a family history of thyroid cancer: a case report and literature review

Differentiated thyroid carcinoma is a rare malignancy in children. It represents 0.4% to 3.0% of all childhood malignancies, with greater than 70% of cases presenting between the ages of 11 to 17 years and is exceptionally rare in children under 5 years of age. The most common type of differentiated thyroid carcinoma in children is papillary thyroid carcinoma, most of which are believed to be related to radiation exposure and only approximately 5% of cases have a family history of papillary thyroid cancer. In this report, we present a papillary thyroid carcinoma in a 3-year-old American boy with a family history of thyroid cancer and no known history of radiation exposure. A literature review with discussion on the management and treatment of pediatric papillary thyroid carcinoma follows.

Review of Distribution of Nodal Disease in Differentiated Thyroid Cancers in an Oncosurgical Center in Sri Lanka

BACKGROUND

There are not many publications on the prognostic implications of nodal disease in patients with papillary thyroid cancers (PTC). This study explored the distribution of nodes with respect to the levels, optimal management of the neck for patients with PTC, and its survival advantages.

METHODS

Followup of 79 patients with thyroid cancer (59 with PTC) at the National Cancer Institute, Maharagama, Sri Lanka, was analyzed.

RESULTS

The most common histologic type of all thyroid cancers presenting to the Institute was differentiated PTC which affected 59 patients (74.7%). Of them, 29 (50.0%) had positive lymph node metastases in the neck these nodes were found on clinical examination and confirmed by ultrasound in all. Therefore necessitating a comprehensive neck dissection. Among the patients with nodal disease, 5 had nodes in Level 1 at the time of presentation. All patients in this group had multiple levels of positive nodes. Metachronous nodal disease was found in 9 (31.4%) patients, with a disease-free period ranging from 2 months to 37 years. Among the patients with nodal disease, 13 had a single nodal group involvement and the majority of these were Level 4 nodes (46.2%). Central node (Level 6) involvement was found in nine (15.3%) patients. Multiple nodal group involvement indicating multifocal disease was present in 16 (27.6%) patients. Extracapsular nodal spread at presentation and extracapsular thyroid disease at presentation was 10 (16.9%) and 17 (28.8%), respectively. Nodal neck recurrences during followup were present in 2 patients.

CONCLUSIONS

Level 1 nodal metastases was present if 5 (8.5%) patients in our group. It is recommended that Level 1 nodes be explored during neck resection for PTC. Because 27.6% of the patients had multifocal disease, it may be important to recommend inclusion of a Level 1 clearance in the presence of multiple nodal involvement. There is a subgroup of patients who had highly aggressive nodes, indicated by extracapsular penetration, which even after radical clearance and external beam radiotherapy have a tendency to recur locally. This indicates an important prognostic feature of the nodal disease in PTC. Because 27.6% of the patients studies had multifocal nodal disease, we consider a comprehensive nodal clearance is necessary for patients with clinically positive nodes.

Importance of thyroglobulin levels for diagnosis and monitoring of follicular thyroid carcinoma in an adolescent with severe iodine deficiency

Optimal management of differentiated thyroid cancer in childhood is undetermined. During monitoring of thyroid carcinoma, serum thyroglobulin (hTG) levels provide valuable information. hTG levels not only increase in differentiated thyroid cancers but also in iodine deficiency because of compensation by the thyroid gland. A 14.6 year-old girl was diagnosed with nodular goiter, subclinical hypothyroidism and severe iodine deficiency. She had a very high hTG level. Despite benign fine-needle aspiration biopsy (FNAB), because the hTG level was still very high after treatment with LT4, thyroidectomy was undergone. Cytopathological examination showed minimally invasive follicular thyroid carcinoma. During follow-up, to exclude the presence of persistent/recurrent disease, the hTG level rose to an undesirably high level after withdrawal of TSH suppressive therapy, and radioiodine ablation therapy was applied. This report shows that even if there is an explanation for nodular goiter and high hTG levels, such as iodine deficiency, malignancy cannot be ruled out without thyroidectomy. FNAB is not reliable especially in iodine deficient areas. Serum hTG measurement is a valuable tool for both diagnosis and follow-up of differentiated thyroid carcinoma in children.