Thyroid cancer in children: the Royal Marsden Hospital experience

Pediatric Papillary Thyroid Carcinoma: Outcomes After Surgery Without Adjuvant Radioactive Iodine

CONTEXT

Pediatric papillary thyroid carcinoma (PTC) is usually treated with total thyroidectomy followed by radioactive iodine (RAI). Recently, RAI has been used more selectively based on surgical pathology and postoperative dynamic risk stratification (DRS).

OBJECTIVE

To describe patients with pediatric PTC not initially treated with RAI and their disease outcomes.

METHODS

This was an ambispective study at a tertiary cancer center of patients < 19 years diagnosed from January 1, 1990, to December 31, 2021, with stage 1 PTC who intentionally were not treated with RAI within a year of diagnosis. We assessed clinical characteristics, management, and disease outcomes using DRS.

RESULTS

Of 490 PTC patients, we identified 93 eligible patients (median age at diagnosis 16 years; 87% female), including 46 (49%) with cervical lymph node metastases. Initial management included total thyroidectomy ± neck dissection (n = 69, 75%), lobectomy ± neck dissection (n = 20, 21%), or a Sistrunk procedure for ectopic PTC (n = 4, 4%). After a median follow-up of 5.5 years (range 1-26), most patients (85/93; 91%) remained disease-free with no further therapy. Persistent (n = 5) or recurrent (n = 3) disease was found in 9% of the entire cohort. Four patients ultimately received RAI, of which only 1 clearly benefitted, and additional surgery was performed or planned in 4 patients, 2 of whom had an excellent response at last follow-up.

CONCLUSION

Selected pediatric PTC patients, even those with lymph node metastases, may not require therapeutic 131I and can avoid the unnecessary risks of RAI while still benefitting from the excellent long-term outcomes that are well described for this disease.

The Prognostic Power of Preablation Stimulated Thyroglobulin in Children With Differentiated Thyroid Cancer

OBJECTIVE

To analyze prognostic factors in children with differentiated thyroid carcinoma (DTC) who have been treated in a single center in the last 27 years.

METHODS

We studied 126 children (≤18 years old) who have been treated with near-total thyroidectomy followed by radioiodine therapy and thyroid hormone replacement. Follow-up of the patients was done 2, 6, and 12 months after treatment and then by yearly evaluation. Response to treatment was defined according to the American Thyroid Association guidelines.

RESULTS

Papillary thyroid cancer was the main pathology (93.7%), and 52.4% of the patients had lymph node metastasis at presentation, which was extensive (>5) in 30% of the patients. Distant metastasis was seen in 8.8%. The mean initial dose of I-131 was 74 ± 42.2 MBq/kg. The median follow-up was 59 months and the median time to achieve an excellent response was 29 months. The preablation stimulated thyroglobulin (psTg) level was 202.4 ± 301.8 ng/mL in patients with first-year incomplete response compared with 11.2 ± 17.5 ng/mL in others (P =.001). Furthermore, using logistic regression, the psTg level was found to be the only significant predictor of distant metastasis, and psTg ≥ 13.75 ng/mL was the most powerful predictor of first-year incomplete response. Moreover, distant metastasis was more common in boys than in girls, and it took longer time for boys to achieve an excellent response.

CONCLUSION

The psTg level was the only significant predictor of distant metastases in children with DTC, and psTg ≥ 13.75 ng/mL was the most powerful predictor of first-year incomplete response.

Clinical Significance of Tumor Size in Gross Extrathyroidal Extension to Strap Muscles (T3b) in Papillary Thyroid Carcinoma: Comparison with T2

The purpose of the present study was to compare the risk of recurrence between T2 and T3b papillary thyroid carcinoma (PTC) and the effect of tumor size on survival in T3b disease. A total of 634 patients with PTC who underwent thyroid surgery at a single center were retrospectively analyzed. Clinicopathological characteristics were compared according to the T category in the TNM staging system, with T3b divided into T3b-1 (tumor size, ≤2 cm) and T3b-2 (tumor size, 2–4 cm). Disease-free survival (DFS) and recurrence risk were compared between T2, T3b, T3b-1, and T3b-2. Tumor size was significantly larger in T2 than in T3b. A significant difference in recurrence was observed between T2 and T3b-2 but not between T2 and T3b-1. T3b-2 was identified as a significant risk factor for PTC recurrence. A significant difference in the DFS curve was observed between T2 and T3b-2. However, no significant differences in survival were observed between T2 and T3b or T3b-1. These results indicate that the prognostic impact of T3b may vary depending on tumor size. Further studies are required to determine the need for T classifications that account for tumor size and gETE invasion of the strap muscles.

Treatment of hypothyroidism in infants, children and adolescents

In 2014, treatment guidelines from the American Thyroid Association reflected the general consensus that levothyroxine (LT4), adjusted to maintain a normal thyrotropin (TSH) level, is the preferred method for treatment of hypothyroidism. Although this is generally applicable to children, there are subsets of children for whom the diagnosis and treatment of hypothyroidism are problematic. These include children with congenital hypothyroidism (CH), low birth weight (LBW) and very low birth weight (VLBW), Down syndrome (DS), subclinical hypothyroidism, and obesity. In this Review, we focus on the progress and remaining pitfalls in diagnosis and treatment of hypothyroidism in these and other groups.

Epidemiology and treatment of head and neck malignancies in the AYA generation

The Adolescent and Young Adult (AYA) population refers to the population of young adults and adolescents in the 15-39 years age group. This population subgroup experiences various important life events. Head and neck malignancies are rare tumors, in general, but they are extremely rare in the AYA population. When analyzed by the primary site of the tumors, thyroid gland, soft tissue, and nasopharyngeal malignancies are the most commonly encountered head and neck malignancies in the AYA generation. The most common histopathologic subtypes are carcinomas (thyroid carcinoma, nasopharyngeal carcinoma) and rhabdomyosarcoma. Therefore, in this review, the author discusses these three diseases in the AYA population in detail. Especially, patients with parameningeal rhabdomyosarcoma are at a high risk of dysfunction and facial deformity. Infertility problems may also occur as long-term sequelae of chemotherapy in this population. Radiation therapy might be associated with considerable morbidity. Complications such as cataract, xerostomia, hearing loss, neck fibrosis, and trismus are also common. Head and neck surgeons and medical oncologists should choose the optimal treatment taking into account the curability of the tumors relative to the long-term adverse events of treatment use. Finally, little evidence has been accumulated on head and neck malignancies in the AYA population, and it is urgently necessary to build a high level of evidence for the future.

Age, American Thyroid Association Risk Group, and Response to Therapy Are Prognostic Factors in Children With Differentiated Thyroid Cancer

CONTEXT

Against the background of increasing incidence, pediatric differentiated thyroid carcinoma (DTC) frequently presents with advanced disease and high recurrence rates while prognosis remains excellent.

BACKGROUND

We investigated the use of a pediatric classification and an adult response to therapy risk stratification for pediatric DTC patients and their implications for adaptation of treatment and follow-up.

METHODS

Data from patients aged <18 years with a diagnosis of primary DTC, registered with the German Pediatric Oncology Hematology-Malignant Endocrine Tumor registry since 1995, were analyzed. For risk prediction, patients were retrospectively assigned to the American Thyroid Association (ATA) risk groups and evaluated for response to therapy.

RESULTS

By October 2019, 354 patients with DTC had been reported (median age at diagnosis 13.7 years, range 3.6-17.9) with lymph node and distant metastases in 74.3% and 24.5%. Mean follow-up was 4.1 years (range 0-20.6). Ten-year overall and event-free survival (EFS) rates were 98.9% and 78.1%. EFS was impaired for patients with lymph node and distant metastases (P < .001), positive postoperative thyroglobulin (P = .006), incomplete resection (P = .002), sequential surgeries to achieve total thyroidectomy (P = .042), invasion of capsule (P < .001) and lymph vessels (P = .005), infiltration of surrounding soft tissues (P < .001), tumor multifocality (P < .001), ATA intermediate- and high-risk group (P < .001), and age <10 years (P < .001). Multivariate analysis revealed age <10 years at diagnosis, ATA high-risk level, and poor response to therapy as significant negative prognostic factors for EFS.

CONCLUSION

Age, ATA risk group, and response to therapy emerged as significant prognostic factors for EFS in pediatric patients with DTC, requiring risk-adapted individualized therapy and follow-up.

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.

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.

Management of pediatric differentiated thyroid cancer: An overview for the pediatric oncologist

Differentiated thyroid cancer (DTC) is the most common childhood thyroid malignancy. The standard of care for pediatric DTC is total thyroidectomy followed by radioactive iodine (RAI) treatment when indicated. Molecular changes and potential therapeutic targets have been recently described in pediatric thyroid cancer. Pediatric oncologists are increasingly involved in the evaluation of thyroid nodules in childhood cancer survivors and in the management of advanced thyroid cancer. In 2015, the American Thyroid Association published management guidelines for children with DTC. We provide an overview of the current standard of care and highlight available targeted therapies for progressive or RAI refractory DTC.

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.

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.

Factors associated with distant metastasis in pediatric thyroid cancer: evaluation of the SEER database

Objectives Controversies regarding factors associated with distant metastasis in pediatric thyroid cancer remain among the scientific community. The aim of this study was to investigate factors influencing distant metastasis in pediatric thyroid cancer. Methods We reviewed 1376 patients (aged 2 to 18 years) with thyroid cancer treated between 2003 and 2014. Data collected and analyzed included sex, race, age at diagnosis, year of diagnosis, pathological type, number of tumor foci, tumor extension, T-stage, N-stage, surgical procedure and radiation. Univariate and multivariate analyses were conducted to evaluate factors influencing distant metastasis of pediatric thyroid cancer. Results In the univariate analysis, factors influencing distant metastasis of thyroid cancer were age at diagnosis (P < 0.001), N-stage (P < 0.001), number of tumor foci (P = 0.003), tumor extension (P < 0.001) and T-stage (T1 vs T2 (P = 0.803), T3 (P < 0.001) and T4 (P < 0.001)). In multivariate analysis, factors influencing distant metastasis of thyroid cancer were age at diagnosis (P = 0.001), N-stage (P < 0.001) and T-stage (T1 vs T3 (P = 0.036) and T4 (P < 0.001)). Sex, race, year of diagnosis, pathological type, number of tumor foci, tumor extension, surgical procedure and radiation had no significant influence on distant metastasis (all P > 0.05). Furthermore, according to chi-squared test, younger pediatric thyroid cancer patients with higher T- and N-stages are more likely to have distant metastasis. Conclusion Age at diagnosis, T-stage and N-stage influence distant metastasis of thyroid cancer patients aged 2 to 18 years; accordingly, more radical treatments may need to be used for patients with those risk elements.

A scoring system to predict recurrence in patients with differentiated thyroid cancer

OBJECTIVES

Though predictive models have been constructed to determine the risk of recurrence in differentiated thyroid carcinoma, various aspects of these models are inadequate. Therefore, we aimed to construct, internally validate and implement on a mobile application a scoring system to determine this risk within 10 years.

DESIGN

A retrospective cohort study in 1984-2016.

SETTING

A Spanish region.

PARTICIPANTS

We enrolled 200 patients with differentiated thyroid carcinoma without distant metastasis at diagnosis.

MAIN OUTCOME MEASURES

Time-to-recurrence. A risk table was constructed based on the sum of points to estimate the likelihood of recurrence. The model was internally validated and implemented as a mobile application for Android.

RESULTS

Predictive factors were follicular histology, T, N and multifocality. This risk table had a C-statistic of 0.723. The calibration was satisfactory.

CONCLUSIONS

This study provides an instrument able to predict rapidly and very simply which patients with differentiated thyroid carcinoma have a greater risk of recurrence.

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

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

Fusion Oncogenes Are the Main Genetic Events Found in Sporadic Papillary Thyroid Carcinomas from Children

BACKGROUND

Previous studies reported significant differences in the clinical presentation and outcomes of papillary thyroid carcinoma (PTC) in pediatric patients compared with adults. Previous studies have suggested that the clinicopathological differences observed between pediatric and adult PTCs may be due the existence of distinct genetic alterations. However, the knowledge of genetic events in pediatric PTCs is based primarily on studies in radiation-exposed PTCs or in the few studies that enrolled predominantly adolescent patients. The aim of this study was to characterize the known oncogenic alterations of the MAPK pathway found in adult and radiation-exposed PTCs in a cohort of predominantly sporadic pediatric PTC patients.

METHODS

Thirty-five pediatric PTCs were screened for the most prevalent fusions (RET/PTC1, RET/PTC2, RET/PTC3, ETV6-NTRK3, and AGK-BRAF) and point mutations (BRAFV600E and NRASQ61) described in sporadic pediatric PTCs. The mutational status was correlated with clinicopathological data.

RESULTS

Mutations were found in 20 out of 35 (57%) PTC cases. Fusion oncogenes were the main genetic alterations found. RET/PTC1-3 rearrangements were found in 13 (37%), ETV6-NTRK3 in 3 (9%), AGK-BRAF in 4 (11%), and BRAFV600E in 3 (9%). No mutation was found in NRASQ61. BRAFV600E was associated with older age and larger tumor size (p < 0.05), and RET/PTC3 was associated with a larger tumor size and multifocality (p < 0.05).

CONCLUSIONS

The genetic signature in this cohort was remarkably different than that observed in adults. Although observed at a lower prevalence, the spectrum of mutations was quite similar to that described in radiation-exposed pediatric PTCs. As mutations were unidentifiable in over 40% of the PTC cases, more comprehensive studies conducted in these patients will help to decipher the genetic landscape of sporadic pediatric PTCs.

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

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

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.

Predictors of Regional Lymph Node Recurrence after Initial Thyroidectomy in Patients with Thyroid Cancer

Background. Regional lymph node recurrence (RLNR) is common in patients with thyroid cancer but clinicopathological predictors are unclear. We aimed to clarify these predictors and identify patients who would benefit from prophylactic lymph node dissection the most. Method. 343 patients with different types of thyroid cancer were analyzed retrospectively. All patients underwent total thyroidectomy between 2007 and 2013. Results. The median ± interquartile range of patients' age was 40 ± 25 years. 245 (71.4%) patients were female. Regarding the risk of regional lymph node recurrence, we found that male gender, age ≥45 years, non-PTC (i.e., medullary, follicular, and anaplastic types) histopathology, T3 (i.e., tumor size >4 cm in the greatest dimension limited to the thyroid or any tumor with minimal extrathyroid extension), stage IVa, and isolated cervical lymphadenopathy as initial manifestation (ICL) are significant risk factors. T3 (p < 0.001; odds ratio = 156.41, 95% CI [55.72–439.1]) and ICL (p < 0.001; odds ratio = 77.79, 95% CI [31.55–191.81]) were the strongest predictors of regional lymph node recurrence. Conclusion. We found easily achievable risk factors for RLNR in thyroid cancers patients. We suggested that patients with specific clinicopathological features like male gender, age ≥45 years, larger tumor size, and extrathyroidal extension be considered as prophylactic lymphadenectomy candidates.

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.

Pediatric papillary thyroid carcinoma: outcomes and survival predictors in 2504 surgical patients

OBJECTIVE

To evaluate outcomes and predictors of survival of pediatric thyroid carcinoma, specifically papillary thyroid carcinoma.

METHODS

SEER was searched for surgical pediatric cases (≤20 years old) of papillary thyroid carcinoma diagnosed between 1973 and 2011. Demographics, clinical characteristics, and survival outcomes were analyzed using standard statistical methods. All papillary types, including follicular variant, were included.

RESULTS

A total of 2504 cases were identified. Overall incidence was 0.483/100,000 persons per year with a significant annual percent change (APC) in occurrence of 2.07 % from baseline (P < 0.05). Mean age at diagnosis was 16 years and highest incidence was found in white, female patients ages 15-19. Patients with tumor sizes <1 cm more likely received lobectomies/isthmusectomies versus subtotal/total thyroidectomies [OR = 3.03 (2.12, 4.32); P < 0.001]. Patients with tumors ≥1 cm and lymph node-positive statuses [OR = 99.0 (12.5, 783); P < 0.001] more likely underwent subtotal/total thyroidectomy compared to lobectomy/isthmusectomy. Tumors ≥1 cm were more likely lymph node-positive [OR = 39.4 (16.6, 93.7); p < 0.001]. Mortality did not differ between procedures. Mean survival was 38.6 years and higher in those with regional disease. Disease-specific 30-year survival ranged from 99 to 100 %, regardless of tumor size or procedure. Lymph node sampling did not affect survival.

CONCLUSIONS

The incidence of pediatric papillary thyroid cancer is increasing. Females have a higher incidence, but similar survival to males. Tumors ≥1 cm were likely to be lymph node-positive. Although tumors ≥1 cm were more likely to be resected by subtotal/total thyroidectomy, survival was high and did not differ based on procedure.

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

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

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

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

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

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

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.

Clinical risk factors for central lymph node metastasis in papillary thyroid carcinoma: a systematic review and meta-analysis

BACKGROUND

Prophylactic central lymph node dissection (CLND) in clinically node-negative patients remains controversial, and predictive factors for central lymph node metastasis (CLNM) in patients with papillary thyroid carcinoma (PTC) are not well defined. Herein, we conducted a systematic review to quantify the clinicopathologic factors predictive for CLNM in patients with PTC.

METHODS

A systematic search of electronic databases (PubMed, Embase, Cochrane CENTRAL, Scopus and Wanfang Database) for studies published until July 2014 was performed. Cohort, case-control studies and randomized controlled trials that examined clinical risk factors of CLNM were included.

RESULTS

Twenty-five studies (4 prospective and 21 retrospective studies) involving 7,719 patients met final inclusion criteria. From the pooled analyses, male gender (OR 1.93, 95% CI 1.40 to 2.64), tumour multifocality (OR 1.93, 95% CI 1.62 to 2.30), tumour size >0.5 cm (OR 3.48, 95% CI 2.24 to 5.41), capsular invasion (OR 1.91, 95% CI 1.36 to 2.67), extrathyroidal extension (OR 2.42, 95% CI 1.58 to 3.71), lymphovascular invasion (OR 13.29, 95% CI 5.61 to 31.48) and lateral lymph node metastasis (OR 14.33, 95% CI 5.34 to 38.50) were significantly associated with increased risk of CLNM, while age >45 years (OR 0.65, 95% CI 0.51 to 0.83) and lymphocytic thyroiditis (OR 0.70, 95% CI 0.53 to 0.92) resulted in decreased risk of CLNM. Bilaterality and tumour location were not significantly associated with CLNM development (all P > 0.05).

CONCLUSIONS

Our analysis identified several clinicopathologic factors associated with CLNM. These findings may guide the necessity and extent of prophylactic CLND and ultimately improve the outcomes of patients with PTC.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Cerebral metastases from thyroid carcinoma: complete remission following radioiodine treatment

BACKGROUND

Brain metastases arise in roughly 0.9% of all cases of differentiated thyroid cancer. The median survival of adult patients with thyroid carcinoma that has metastasized to the brain is less than one year. Radioactive iodine treatment is only rarely given because its efficacy is not documented. In children, the situation may be different.

METHOD

In 2005, a 15-year-old girl underwent thyroidectomy, and an oxyphilic variant of papillary thyroid carcinoma was found in ectopic thyroid tissue. The patient underwent oral, high-dose radioactive iodine treatment. The post-therapeutic I-131 whole-body scan revealed multiple metastases in the skeleton, lungs, and the soft tissues, along with physiological uptake of the residual thyroid tissue. Magnetic resonance imaging of the head revealed two brain metastases.

RESULTS

When the initial treatment was completed, additional age-adapted high-dose radioactive iodine treatment was given, up to a total activity level of 35 GBq. There followed a complete remission of all metastases in the brain, bones, lungs, and soft tissues. Computed tomography of the chest revealed stable residuals. Over the ensuing 7.5 years of follow-up, the thyroglobulin values steadily declined to less than 2 ng/mL. The patient was asymptomatic at her last follow-up in May 2013. She did not develop any delayed reaction to high-dose radioactive iodine treatment (in particular, she did not develop leukemia or any other secondary malignancy). She remained fertile: after completion of the treatment, she had two healthy children.

CONCLUSION

In this patient with multifocal thyroid carcinoma, a rare entity, radioactive iodine treatment was successful as the single treatment. This case illustrates the point that a given therapeutic modality might succeed in an individual case despite a total or near-total lack of efficacy for most patients in the same situation.

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

BACKGROUND

Cancer of the thyroid gland is rare in children and adolescents. A history of neck irradiation is a well-established risk factor for tumor development, and most previous reports focused on cases that were induced by radiation exposure. We present here a retrospective review of the clinical features, treatment, and long-term outcome of children and adolescents with papillary thyroid cancer (PTC) without a history of radiation exposure who were treated at our institution over a period of ~50 years.

METHODS

We retrospectively investigated 142 PTC patients without an irradiation history who were younger than 20 years of age when treated from 1961 to 2005 (17 males and 125 females; mean age = 16.3 ± 2.7 years; follow-up = 21.8 ± 12.0 years). The clinicopathological results were evaluated using the medical records. Disease-free survival (DFS) and cause-specific survival (CSS) were assessed with the Kaplan-Meier method and compared with the log-rank test. Parametric analyses were performed using Student's t test and nonparametric analyses were performed using the Mann-Whitney U test.

RESULTS

At diagnosis, three patients had distant lung metastasis and 33 had gross neck lymph node (LN) metastasis. All patients were treated with surgery (hemi/partial thyroidectomy in 45 patients, subtotal thyroidectomy in 85, total thyroidectomy in 12, no LN dissection in 50, central compartment dissection in 20, and modified radical neck dissection in 72), and postoperative external beam radiation therapy was administered to 59. Postoperative ablative therapy using I(131) was not performed in this series. Recurrence was found for regional LN (n = 25), lung (n = 9), remnant thyroid (n = 5), and others (n = 4). DFS and CSS at 40 years were 74.1 and 97.5%, respectively. DFS was significantly worse in patients aged <16 years with a family history of thyroid cancer, preoperative neck gross LN metastasis, maximum tumor diameter, and extrathyroidal invasion. Preoperative gross neck LN metastasis and distant metastasis at diagnosis were significant factors for CSS. No other factors contributed to DFS and CSS. When the clinical features of children and adolescents were compared, the incidence of preoperative gross neck LN metastasis and distant metastasis at diagnosis and tumors with a maximum diameter >10 mm were significantly higher in the children group than in the adolescent group. DFS was significantly shorter in the children group than in the adolescent group, but no significant difference was found in CSS between these two groups.

CONCLUSIONS

The prognosis of PTC in children and adolescents is excellent, regardless of the extent of thyroidectomy and LN dissection. We recommend that only children or adolescents with preoperative gross neck LN metastasis and distant metastasis at diagnosis should be subjected to postoperative ablative therapy.

Management of thyroid carcinoma in children and young adults

Thyroid cancers represent the largest group of pediatric carcinomas. Unlike other cancers of childhood, they have not been prospectively studied; instead adult data has been extrapolated to childhood and adolescent treatment. In this article we review the treatment of both well differentiated thyroid cancer (WDTC), as well as medullary thyroid cancer (MTC). The approach to both cancers relies on a low threshold of suspicion, and a willingness to biopsy suspicious lesions. Surgery remains the primary method of curing these patients, although radioactive iodine (RAI) may offer some benefit in WDTC for selected patients. For patients with MTC new medications, such as Vandetanib, may offer some adjuvant benefit following surgery. Lastly, suppression of thyroid stimulating hormone (TSH) may be one of the most beneficial treatments for WDTC.

Thyroid cancer in children: a 20-year study at a Romanian oncology institute

Thyroid carcinoma (TC) has an increasing incidence in the last decade and continues to represent the most frequent form of endocrine tumor. The aim of the study was to analyze the pediatric files of TC from the registry of "Prof. Dr. Ion Chiricuta" Institute of Oncology Cluj-Napoca, Romania (IOCN) and to provide the data related to the impact of nuclear fallout of Chernobyl on this pathology. We studied 72 children with TC treated between 1991 and 2010. The mean age was 15.3 years; the ratio female/male was 6.2:1. Twenty-nine children (40.2%) revealed metastasis in regional lymph nodes or lungs at the initial diagnostic. There were 63 differentiated thyroid carcinoma (DTC), 6 cases with medullary cancer (MC), 1 case with anaplastic carcinoma (AC), and 2 mixed cases. All patients underwent total thyroidectomy and the radioiodine was administered in 64 cases (activities between 1.1 - 28.1 GBq I-131). Fifty-two children (80.5%) are free of disease, 8 are in partial remission and 4 children are in evolution of the disease at minimum 12 months of follow-up. The incidence of TC was significantly increased 10 years after the accident. In the years after, the increasing trendline was stopped and at 25 years, the number of cases is stationary. The diagnosis of pediatric TC is made frequently in metastatic disease and the therapies must be conducted for many years till complete remission. A more clear strategy adapted to children is needed in the future.

The treatment of differentiated thyroid cancer in children: emphasis on surgical approach and radioactive iodine therapy

Pediatric thyroid cancer is a rare disease with an excellent prognosis. Compared with adults, epithelial-derived differentiated thyroid cancer (DTC), which includes papillary and follicular thyroid cancer, presents at more advanced stages in children and is associated with higher rates of recurrence. Because of its uncommon occurrence, randomized trials have not been applied to test best-care options in children. Even in adults that have a 10-fold or higher incidence of thyroid cancer than children, few prospective trials have been executed to compare treatment approaches. We recognize that treatment recommendations have changed over the past few decades and will continue to do so. Respecting the aggressiveness of pediatric thyroid cancer, high recurrence rates, and the problems associated with decades of long-term follow-up, a premium should be placed on treatments that minimize risk of recurrence and the adverse effects of treatments and facilitate follow-up. We recommend that total thyroidectomy and central compartment lymph node dissection is the surgical procedure of choice for children with DTC if it can be performed by a high-volume thyroid surgeon. We recommend radioactive iodine therapy for remnant ablation or residual disease for most children with DTC. We recommend long-term follow-up because disease can recur decades after initial diagnosis and therapy. Considering the complexity of DTC management and the potential complications associated with therapy, it is essential that pediatric DTC be managed by physicians with expertise in this area.

Surgical and pathological characteristics of papillary thyroid cancer in children and adolescents

Background. Thyroid carcinoma is a relatively rare pediatric pathology, comprising around 3% of all childhood tumors. We investigated parameters of tumor aggressiveness, multicentricity, and locoregional metastatic spread patterns in patients up to 18 years of age and made comparison with the older group. All patients were operated upon with total thyroidectomy, with or without lymph-node neck dissection. Results. Patients with papillary carcinoma present with more advanced stage, larger primary tumor, and more commonly present with palpable thyroid and/or neck node. Overall, papillary cancer demonstrated pathological aggressiveness as defined by our criteria in 60%, multicentricity in 40%, and locoregional metastatic foci in 77% of cases. Multicentric tumor foci in both thyroid lobes and tumor aggressiveness were identified as a risk factor for metastatic development. Conclusion. By observing clinicopathological parameters, we demonstrated that papillary thyroid cancer behaves more aggressively in the younger group. We recommend total thyroidectomy with careful intraoperative exploration of thyroid bed and lateral neck in search for possible metastatic spread. In case of positive findings, it is obligatory to perform a standard neck dissection, keeping in mind that neck lymphonodes are primary site of locoregional recurrence. With meticulous attention to technical aspects of operation, perioperative morbidity should be minimal.

An individualized approach to the child with thyroid cancer

Children with differentiated thyroid cancer (DTC) often present with extensive disease that inclined clinicians in prior decades toward aggressive treatment including total thyroidectomy, radical neck dissection and universal prescription of radioactive iodine (RAI). Recent series with 40 years of follow-up have shown that fewer than 2% of children ultimately die from DTC, but they may have increased all-cause mortality from second malignancies that might be related to previous radiation exposure. In this article, we review data to support the notion that an individualized, risk-stratified approach to therapy should be used for children with DTC. Ideally this will provide aggressive therapy for those in whom aggressive treatment is warranted, but withhold aggressive and risk-associated therapy from those who are not likely to benefit.

Papillary thyroid cancer in children and adolescents does not differ in growth pattern and metastatic behavior

OBJECTIVE

To provide comprehensive clinicopathologic data, comparing the growth pattern and metastatic behavior of papillary thyroid cancer between children and adolescents.

STUDY DESIGN

This clinicopathologic investigation included 83 consecutive patients ages 6 to 18 years operated on for papillary thyroid cancer at a tertiary referral center in Germany (1994 to 2009).

RESULTS

There was no difference in sex distribution, re-operation rate, medical history of external radiation, multifocal tumor growth, number of thyroid cancers, extrathyroidal tumor growth, lymph node metastasis, numbers of involved and removed nodes or distant metastasis among patients ages 6 to 11, 12 to 15, and 16 to 18 years. Patients with extrathyroidal growth, unlike those with intrathyroidal growth, had larger tumors, especially in the oldest age group (means of 20, 26, and 44 mm for patients ages 6 to 11, 12 to 15, and 16 to 18 years; P=.015); the statistical significance was lost after correction for multiple testing.

CONCLUSION

Having comparable extent of disease, children should not undergo less extensive neck operations than adolescents for papillary thyroid cancer.

Long-term outcome in 215 children and adolescents with papillary thyroid cancer treated during 1940 through 2008

BACKGROUND

Controversy exists regarding the aggressiveness of initial therapy in childhood papillary thyroid cancer (PTC). Few studies with long-term outcome exist and second primary malignancies have rarely been analyzed.

METHODS

We studied 215 PTC patients younger than 21 years old managed during 1940 through 2008. The patients were aged 3-20 year old (median age = 16 years); the median follow-up was 29 years. Recurrence and mortality details were taken from a computerized database.

RESULTS

Median primary tumor size was 2.2 cm. Six percent had distant metastases at presentation, 5% had incomplete tumor resection, 86% had nodes removed at initial surgery, and 78% had nodal metastases. After complete surgical resection, PTC recurred in 32% by 40 years. At 20 years, the recurrence rates at local, regional, and distant sites were 7, 21, and 5%, respectively. During 1940-1969, local and regional recurrence rates after unilateral lobectomy (UL) were significantly (P < 0.001) higher than after bilateral lobar resection (BLR). During 1950-2008 radioiodine remnant ablation (RRA) was administered within 18 months to 32%; it did not diminish the 25-year regional recurrence rate of 16% seen after BLR alone (P = 0.86). Only two fatal events from PTC occurred at 28 and 30 years, for a cause-specific mortality at 40 years of only 2%. All-causes mortality rates did not exceed expectation through 20 years, but from 30 through 50 years, the number of deaths was significantly (P < 0.001) higher than predicted. Fifteen of 22 deaths (68%) resulted from nonthyroid malignancy.

CONCLUSION

Survival from childhood PTC should be expected, but later death from nonthyroid malignancy is disconcerting. Seventy-three percent of those who died from nonthyroid malignancy had received postoperative therapeutic irradiation.

Differentiated thyroid carcinoma in pediatric patients: comparison of presentation and course between pre-pubertal children and adolescents

OBJECTIVE

To evaluate the clinical characteristics, course, and outcome of differentiated thyroid carcinoma (DTC) in pre-pubertal children compared with adolescents.

STUDY DESIGN

The records of 10 pre-pubertal and 17 pubertal patients in whom DTC was diagnosed and who were observed in our tertiary pediatric endocrine clinic were reviewed. Extension of tumor at presentation, treatment modality, course, and outcome were analyzed.

RESULTS

A positive family history of DTC was more prevalent in the pre-pubertal group (P = .037). At diagnosis, they had a greater degree of extrathyroid extension (P = .012), lymph node involvement (P = .009), and lung metastases (P = .009). The extent of surgery was similar in both groups, whereas the weight-adjusted radioiodine (I(131)) ablative dose was higher in the pre-pubertal group (P = .004). During the median follow-up of 5 years, the overall survival rate was 100% for both groups, with no significant difference in evidence of residual tumor after initial therapy or the recurrence rate.

CONCLUSION

DTC has a more aggressive presentation in pre-pubertal children. Rigorous initial surgical and I(131) treatment, followed by thyrotropin suppression, was found to result in an outcome similar to that achieved in the pubertal group.

UICC-2002 TNM classification is not suitable for differentiated thyroid cancer in children and adolescents

BACKGROUND

Recently the UICC-TNM classification for differentiated thyroid cancer (DTC) was changed neglecting the special circumstances for children affected by the disease. While the 1997 TNM classification grouped tumours </=1 cm as T1, the 2002 system changed this to a margin of </=2 cm. The consequences of this change were evaluated by analysing patients enrolled in the multicentre interdisciplinary therapy study of the German Society of Paediatric Oncology and Haematology (GPOH) on malignant endocrine tumours in children and adolescents, GPOH-MET 97.

PROCEDURE

Between 1998 and 2005, 82 patients with histologically proven DTC entered the study. Patients classified according to UICC-TNM classification 1997 were reclassified according to the new classification (2002/2003) and vice versa by cross checking with original pathologist's reports.

RESULTS

Twenty males and 62 females at a mean age of 12.5 years were evaluated. We observed a definite shift from patients formerly classified as T2 (1-4 cm) to category T1 (</=2 cm) according to the 2002 TNM classification. Among these patients a threefold increase of lymph node involvement and/or distant metastases could be demonstrated.

CONCLUSIONS

The 2002 UICC-classification may have a disadvantage for children with tumours measuring between 1 and 2 cm, as those are now classified as T1. A high rate of lymph node involvement in this group reflects the risk of under-diagnosis and -treatment of this group. The current TNM classification for DTC in children should be changed taking the physiological and anatomical differences between children and adults into consideration.

Differentiated Pediatric Thyroid Cancer: Correlates With Adult Disease, Controversies in Treatment

The biologic behavior of differentiated thyroid cancer can differ between adults and children, especially in those children younger than 10 years of age. Unlike adults, young children typically present with advanced disease at diagnosis. Despite this, children respond rapidly to therapy and have an excellent prognosis that is significantly better than that of their adult counterparts with advanced disease. In contradistinction to adults, children with thyroid cancer also have higher local and distant disease recurrences with progression-free survival of only 70% at 5 years, mandating life-long surveillance. Although thyroid cancer is the most common carcinoma in children, overall incidence is low, a factor that has prevented performance of a controlled, randomized, prospective study to determine the most efficacious treatment regimen in this age group. So, although extensively investigated, treatment of pediatric patients with differentiated thyroid cancer remains controversial. This article reviews the current controversies in the treatment of pediatric differentiated thyroid cancer, focusing on issues of optimal initial and subsequent therapy as well as that of long-term follow-up. Our approach to treatment is presented. In so doing, similarities and differences between adults and children with differentiated thyroid cancer as regards unique considerations in epidemiology, diagnosis, staging, treatment, therapy-related late effects, and disease surveillance are presented. The expanding use of and appropriate roles for thyrogen and fluorine-18-fluorodeoxyglucose positron emission tomography in disease evaluation and surveillance will be addressed.

Childhood thyroid cancer in Belarus, Russia, and Ukraine after Chernobyl and at present

Thyroid cancer in children is usually rare, but in the individuals exposed to radiation risk of disease increases considerably. After the Chernobyl accident in 1986, an over 10-fold maximal elevation in the incidence of thyroid cancer was registered about a decade later, cumulatively resulting in more than a thousand of newly diagnosed cases in children who lived in the territories of Belarus, Russia, and Ukraine affected by radioactive fallouts. Experience from the epidemic substantially promoted knowledge in clinical pediatric oncology, pathology and basic sciences. This article overviews epidemiology, clinical features, results of treatment and follow-up of childhood patients with radiation-induced Chernobyl thyroid cancer in comparison to sporadic cases diagnosed at present. In addition, we discuss general issues of pathology and molecular findings in childhood thyroid carcinomas.

Comprehensive clinical assessment of 740 cases of surgically treated thyroid cancer in children of Belarus

OBJECTIVE

A retrospective study was designed to evaluate the results of surgical treatment and follow-up data in thyroid cancer patients less than 15 years old at the time of surgery.

SUMMARY BACKGROUND DATA

Pediatric thyroid carcinomas have a high rate of lymph nodal and distant metastases. Risk factors for recurrences and postoperative morbidity have not been assessed yet in a representative series.

METHODS

The group included 740 pediatric patients with thyroid cancer. Total thyroidectomy was performed in 426 (57.6%), lobectomy in 248 (33.5%), subtotal thyroidectomy in 58 (7.8%) cases, and 8 patients (1.1%) underwent partial lobectomy.

RESULTS

The mean follow-up period was 115.8 months (range, 1.5-236.4 months). Recurrence was diagnosed in 204 cases (27.6%), including 73 local relapses (9.9%), 90 distant metastases (12.2%), and a combination of local and distant recurrences in 41 (5.5%) patients. Multivariate statistical assessment revealed the following independent parameters significantly associated with the risk of recurrent nodal disease: a young age at diagnosis, multifocal carcinomas, N1 status, and lack of neck lymph node dissection. For lung metastases, the significant risk factors were female gender, young age at diagnosis, and presence of symptoms. The observed 5- and 10-year survival for the entire group was 99.5% and 98.8%, respectively. Postoperative hypoparathyroidism was significantly associated with multifocal tumors, central compartment removal, and ipsilateral dissection.

CONCLUSIONS

Total thyroidectomy followed by radioiodine therapy is an optimal treatment strategy that makes it possible to achieve a cure in a vast majority of pediatric patients with differentiated thyroid carcinomas. Risk of recurrence is strongly associated with tumor stage, extent of surgery, the young patient's age, and presence of symptoms at diagnosis.

Papillary thyroid cancer: medical management and follow-up

The incidence of epithelial derived thyroid cancer (papillary thyroid cancer and follicular thyroid cancer, known collectively as differentiated thyroid cancer) is rising. About 80% of patients with thyroid cancer have PTC and are best treated with thyroidectomy and functional lymph node dissection, followed by radioiodine ablation or therapy and performance of a posttreatment whole-body scan, followed by thyroid stimulating hormone (TSH) suppression. One year after radioiodine administration, the use of sensitive thyroglobulin (Tg) assays can separate the vast majority of patients with persistent disease from those who are free of disease and unlikely to have recurrent disease all without the need for repeat whole-body radioiodine imaging. Patients with detectable serum Tg during TSH suppression (Tg-on) or Tg that rises above 2 ng/mL after TSH stimulation (TSH-Tg) are highly likely to harbor residual tumor. TSH stimulation can be achieved using either thyroid hormone withdrawal or recombinant human TSH (rhTSH). Highly skilled screening neck ultrasonography can identify a few additional patients with subcentimeter residual neck lymph node metastases not detected by TSH-Tg. However, ultrasonography and chest computed tomography (CT) are most critical for tumor localization in those patients with Tg values that suggest residual disease or in those patients with persistent antithyroglobulin antibodies (TgAb) that falsely lower Tg measurement. TgAb quantitative titers typically resolve steadily over just a few years in patients free of disease after initial therapy. Another paradigm shift is the recognition that most patients who eventually achieve freedom from disease do so by surgery with fewer patients cured by repetitive radioiodine treatments, and even fewer cured with external beam radiation. Patients who appear to be free of disease require a lifetime of follow-up to optimize levothyroxine treatment, and they will undergo periodic stimulation testing because some will still manifest recurrent disease. Patients with persistent disease despite negative ultrasonography, chest CT, and whole-body radioiodine imaging may have a tumor identified by fluorodeoxyglucose positron emission tomography, optimally performed with combined TSH stimulation and image fusion with CT or magnetic resonance imaging. Patients with metastatic disease who are unresponsive to conventional treatment are encouraged to participate in increasingly available thyroid cancer-specific clinical trials using targeted experimental oral or intravenous chemotherapeutic agents to address this tumor that has historically proven resistant to conventional chemotherapeutic agents.