Thyroid Cancer in Pediatrics

MANAGEMENT OF DIFFERENTIATED THYROID CANCER: THE STANDARD OF CARE

In the past decade the management of differentiated thyroid cancer (DTC) underwent a paradigm shift towards the use of risk-stratification with the goal of maximizing benefit and minimizing morbidity of radioiodine (¹³¹I) therapy. ¹³¹I therapy is guided by information derived from surgical histopathology, molecular markers, postoperative diagnostic radioiodine scintigraphy and thyroglobulin (Tg) levels. ¹³¹I is used for diagnostic imaging and therapy of DTC based on physiologic sodium-iodine symporter expression in normal and neoplastic thyroid tissue. We summarize the essential information at the core of multidisciplinary DTC management, which emphasizes individualization of ¹³¹I therapy according to the patient's risk for tumor recurrence.

Treating papillary and follicular thyroid cancer in children and young people: Single UK-center experience between 2003 and 2018

AIM

Differentiated thyroid cancer (DTC) in children and adolescents is rare and data about its presentation and management are not well known. The aim of this study was to provide evidence of the current practice in the United Kingdom before the launch of the Rare National Paediatric Endocrine Tumours Guidelines (to be published in 2020).

METHODS

Seventy-two children and adolescents with DTC (<18 years) who were treated at our institution between 2003 and 2018 were identified and their presentation, treatment and outcomes were reviewed.

RESULTS

Median age at presentation was 12.7 years [range: 1-18] and fifty-two (72%) were girls. Fifty (69.4%) children and adolescents presented with a thyroid nodule. Thirteen (18%) had cervical adenopathy and seven of them (54%) underwent an excision biopsy under GA. Eight patients (11%) had evidence of lung metastases at presentation. Twenty-four patients (33%) underwent a hemithyroidectomy and 22 of those had a completion thyroidectomy subsequently, ten (14%) a total thyroidectomy alone and 37 (51%) a total thyroidectomy with lymph nodes dissection. Seventy patients (97%) underwent adjuvant RAI at our institution. The median number of children and adolescents managed per year was five [range: 0-10]. After an overall median follow-up of 40 months, eight patients (11%) had developed recurrent disease. The 1- and 5-year recurrence-free-survival-rates were 93% and 87%, respectively. Overall survival was 100%, with eight children and adolescents (11%) being alive with disease.

CONCLUSION

This study confirms that DTC in children and adolescents is uncommon, is frequently advanced at presentation and has considerable recurrence rates. Despite this, overall survival is excellent. Although the work-up was generally appropriate (image-guided cytology), open biopsy for the diagnosis of lymph node involvement was still employed. The introduction of a specific UK guideline for this age-group will likely result in more tailored-made treatment-pathways and thereby hopefully improve quality and outcomes even further.

TYPE OF STUDY

Prognosis study.

LEVEL OF EVIDENCE

Level IV.

EV PD-L1 is Correlated With Clinical Features and Contributes to T Cell Suppression in Pediatric Thyroid Cancer

CONTEXT

The contribution of blood extracellular vesicular (EV) programmed death-ligand 1 (PD-L1) and programmed death-1 (PD-1) in papillary thyroid cancer (PTC) is uncertain.

OBJECTIVE

We sought to determine the relationship of EV PD-L1/PD-1 with the clinical features of pediatric PTC and the role of EV PD-L1 in immunosuppression.

MAIN OUTCOME MEASURES

Plasma levels of EV and soluble PD-L1 and PD-1 and levels of plasma cytokines in children with PTC and controls were determined by enzyme-linked immunosorbent assay. Levels of tumor PD-L1 and the tumor-infiltrating lymphocyte (TIL) score were determined by immunohistochemistry. Correlations of the plasma PD-L1/PD-1 level with clinicopathological characteristics, levels of plasma cytokines, tumor PD-L1 expression, and TIL score were analyzed. T-cell suppression by EVs from PTC patients was determined by incubation of PD-L1high or PD-L1low EVs with activated CD8+ T cells. Changes in CD69 and PD-1 expression and changes in tumor necrosis factor-α (TNFα) and interferon-γ (IFNγ) secretion were measured by flow cytometry.

RESULTS

The levels of plasma PD-L1/PD-1 were significantly higher in children with PTC than in controls. The levels of plasma EV PD-L1 significantly correlated with tumor T stage, tumor PD-L1 expression, TIL score, and plasma cytokine content. Levels of plasma soluble PD-1 significantly correlated with patient age, plasma EV PD-L1, and IFNα concentration. PD-L1high EVs significantly inhibited the activation of CD8+ T cells.

CONCLUSIONS

Plasma levels of EV PD-L1, but not soluble PD-L1, were associated with tumor T stage in children with PTC. Plasma EV PD-L1 emerges as a useful metric for assessing tumor T stage and T cell suppression in PTC.

Pediatric Differentiated Thyroid Cancer: Our Experience

Objectives: To report our experience in the management of thyroid cancer in children and adolescents in a tertiary referral hospital and regional cancer institute as compared to previously published data.

Methods: A retrospective study was conducted for patients diagnosed with differentiated thyroid cancer (DTC) who received treatment during the period from January 2014 to August 2018. Medical reports from our hospital database were extracted and information of those under 18 years old were discussed regarding their demographics, treatment received, and follow-up outcomes.

Results: Out of 300 patients with DTC diagnosed in the period of study, 12 were 18 years old or less (4%). Female to male ratio was 5:1. Their ages ranged from nine to 18 years old (average: 13.1 years). One patient had a positive family history for DTC, and one patient had lung metastasis. Total thyroidectomy and postoperative ¹³¹I were performed for all patients. The median follow-up period was 1.75 years (range: six months to four years). Eleven patients have shown complete remission after treatment (91.6%), and one case has had persistent disease.

Conclusions: Pediatric thyroid cancer is not uncommon. Despite its aggressiveness in this age group, outcomes are more favorable than in adults. We report our experience in the diagnosis and management of pediatric DTC in our community with satisfactory outcomes and comparable results to literature reports. Future studies are needed to evaluate the long-term complications of radioiodine therapy.

Thyroid Ultrasound: More Sensitive than Radioactive Iodine Imaging in Detecting Recurrence of Papillary Thyroid Cancer in Two Pediatric Patients

BACKGROUND

Papillary thyroid cancer (PTC) is an uncommon pediatric disease with an excellent prognosis. In follow-up surveillance, neck ultrasound (US), basal and thyroid-stimulating hormone-stimulated serum thyroglobulin (Tg) levels, and diagnostic whole-body radioactive iodine scans (DxWBS) have been traditionally used in both adults and children for the detection of recurrence or metastases of PTC.

METHODS

Two pediatric patients with metastatic PTC were followed after standard ablative treatment with routine neck US and serum Tg levels, as well as periodic DxWBS.

RESULTS

Neck US identified recurrent and metastatic PTC which DxWBS failed to detect.

CONCLUSION

Neck US was superior to DxWBS in the detection of recurrent PTC in these 2 pediatric patients. These findings are consistent with the 2015 American Thyroid Association (ATA) Guidelines that neck US is an ideal imaging modality in pediatric patients for the surveillance of PTC local recurrence or lymph node metastases.

Up-regulated lipocalin-2 in pediatric thyroid cancer correlated with poor clinical characteristics

BACKGROUND

The incidence of thyroid cancer is fast increasing in both adults and children. The pediatric thyroid cancer had often already progressed to a more advanced stage of the disease at diagnosis. Early detection of pediatric thyroid cancer has been a problem for many years. Lipocalin-2 (Lcn2) has been reported to be over-expressed in cancers of diverse histological origin and it facilitates tumorigenesis by promoting survival, growth, and metastasis.

METHODS

The plasma Lcn2 concentration of 28 Chinese papillary thyroid cancer (PTC) children and 24 healthy controls was measured. Immunostaining for Ki-67 of tumor tissue from PTC children was performed. The expression levels of Lcn2 and NFκB in PTC tissue and peri-carcinoma tissue of PTC children were measured through Western blot.

RESULTS

The plasma concentration of Lcn2 was significantly elevated in pediatric PTC patients compared with healthy controls. Besides, the plasma Lcn2 concentration significantly correlated with clinical characteristics, NFκB level, and Ki-67 positive rate of nucleus in tissue of PTC.

CONCLUSION

This is the first study to evaluate the plasma Lcn2 in pediatric PTC patients. It is possible that the plasma Lcn2 may be a new biomarker of pediatric thyroid cancer. Further studies are needed to explore the definite role and mechanism of Lcn2 in thyroid cancer, which will help to explore novel diagnostic or therapeutic strategies.