The successful use of sorafenib to treat pediatric papillary thyroid carcinoma

2022 European Thyroid Association Guidelines for the management of pediatric thyroid nodules and differentiated thyroid carcinoma

At present, no European recommendations for the management of pediatric thyroid nodules and differentiated thyroid carcinoma (DTC) exist. Differences in clinical, molecular, and pathological characteristics between pediatric and adult DTC emphasize the need for specific recommendations for the pediatric population. An expert panel was instituted by the executive committee of the European Thyroid Association including an international community of experts from a variety of disciplines including pediatric and adult endocrinology, pathology, endocrine surgery, nuclear medicine, clinical genetics, and oncology. The 2015 American Thyroid Association Pediatric Guideline was used as framework for the present guideline. Areas of discordance were identified, and clinical questions were formulated. The expert panel members discussed the evidence and formulated recommendations based on the latest evidence and expert opinion. Children with a thyroid nodule or DTC require expert care in an experienced center. The present guideline provides guidance for healthcare professionals to make well-considered decisions together with patients and parents regarding diagnosis, treatment, and follow-up of pediatric thyroid nodules and DTC.

Long-term Follow-up of a Toddler with Papillary Thyroid Carcinoma: A Case Report with a Literature Review of Patients Under 5 Years of Age

Papillary thyroid cancer (PTC) is extremely rare in children. Herein, we present a case diagnosed with PTC at 15 months of age. We conducted a literature review of the published cases with PTC under five years of age. A 1.25-year-old male patient had initially presented with a complaint of progressively enlarging cervical mass that appeared four months earlier. On physical examination, a mass located in the anterior cervical region with the largest measurements of around 3x3 cm was detected. Cervical and thyroid ultrasonography showed a 50x27 mm solid mass in the right lateral neck. Excisional biopsy revealed a follicular variant of PTC with capsular invasion. Subsequently, he underwent a complementary total thyroidectomy. He was diagnosed with intermediate-risk (T3N0M0) PTC. He developed permanent hypoparathyroidism. In the first year of the operation, he was treated with radioiodine ablation (RAI) since basal and stimulated thyroglobulin (Tg) levels tended to increase. Whole-body scintigraphy was normal in the first year of RAI ablation. On levothyroxine sodium (LT4) treatment, levels of thyroid stimulating hormone (TSH) and Tg were adequately suppressed. He is now 8.5-years-old and disease-free on LT4 replacement therapy for seven years and three months. Pediatric PTC has different biological behavior and an excellent prognosis compared to adults. The optimal treatment strategy for pediatric TC is total thyroidectomy, followed by RAI ablation. Post-operative management should include regular follow-up, TSH suppression by adequate LT4 therapy, serial Tg evaluation, and radioiodine scanning when indicated.

Factors predicting the risk of biochemical incomplete response in well-differentiated thyroid cancer after total thyroidectomy

BACKGROUND

Differentiated thyroid cancer (DTC) is the most common endocrine carcinoma with an overall good prognosis. However, persistent or recurrent disease (P/R disease) and incomplete biochemical response (BIR) are causes of morbidity. Histopathology and TNM stage may not predict P/R disease and BIR in all patients. Various clinical parameters, histopathological features and preablative-stimulated thyroglobulin (presTg) have been proposed to predicts P/R disease. However, there is uncertainty for presTg cutoff and diagnostic accuracy. The study's objective was to predict the BIR before radioiodine ablation from available clinical, histopathological and biochemical parameters.

METHODS

A retrospective, single-center study, including DTC patients, was done. Demography and factors predicting BIR evaluated.

RESULT

In comparison to the patients in remission, patients with BIR were older (P = 0.042), had higher presTg (P < 0.001), and lymph nodes (LN) metastases [central or lateral compartment (P < 0.001)]. Visualization of LN on whole-body scan (P = 0.014), higher TNM stage (P = 0.001) and distance metastasis (P < 0.001) were also associated with BIR. On multivariate analysis, high presTg (P < 0.001) and LN metastases (LNscan and histopathologically proven LN involvement, P < 0.001) were associated with BIR. A presTg level ≥12.30 ng/ml has high sensitivity (90.6%) and specificity (80.6%) to predict the BIR (odds ratio 39.90).

CONCLUSIONS

The presTg and LN involvement are robust markers that predict BIR. A raised presTg level with LN metastases and nonvisualization of the LN on the whole-body scan is a worrying feature for the future BIR. We propose the inclusion of high presTg as a high-risk factor in DTC.

Targeted Oncogene Therapy Before Surgery in Pediatric Patients With Advanced Invasive Thyroid Cancer at Initial Presentation: Is It Time for a Paradigm Shift?

Importance

Initial data suggest the effectiveness of oncogene-specific targeted therapies in inducing tumor regression of diverse cancers in children and adults, with minimal adverse effects.

Observations

In this review, preliminary data suggest that systemic therapy may be effective in inducing tumor regression in pediatric patients with unresectable invasive thyroid cancer. Although most pediatric patients with thyroid cancer initially present with operable disease, some children have extensive disease that poses substantial surgical challenges and exposes them to higher than usual risk of operative complications. Extensive disease includes thyroid cancer that invades the trachea or esophagus or encases vascular or neural structures. Previous efforts to manage extensive thyroid cancer focused on surgery with near-curative intent. With the recent development of oncogene-specific targeted therapies that are effective in inducing tumor regression, with minimal drug-associated adverse effects, there is an opportunity to consider incorporating these agents as neoadjuvant therapy. In patients with morbidly invasive regional metastasis or with hypoxia associated with extensive pulmonary metastasis, neoadjuvant therapy can be incorporated to induce tumor regression before surgery and radioactive iodine therapy. For patients with widely invasive medullary thyroid cancer, in whom the risk of surgical complications is high and the likelihood of surgical remission is low, these agents may replace surgery depending on the response to therapy and long-term tolerance.

Conclusions and Relevance

With oncogene-specific targeted therapy that is associated with substantial tumor regression and low risk of adverse reactions, there appears to be an opportunity to include children with advanced invasive thyroid cancer in clinical trials exploring neoadjuvant targeted oncogene therapy before or instead of surgery.

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

CONTEXT

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Management of Differentiated Thyroid Carcinoma in Pediatric Patients

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

Pediatric Thyroid Cancer: Genetics, Therapeutics and Outcome

An increasing number of children are diagnosed with thyroid cancer. Most patients do not have an identifiable cause; however, tumor predisposition syndromes may be associated with development of both differentiated and medullary thyroid cancer. With an excellent prognosis for most patients, the goal of therapy is to optimize outcome and reduce complications. The increased knowledge of the oncogenic drivers provides opportunities to improve the accuracy of diagnosis, stratify surgery, and select systemic therapy that may be considered for neoadjuvant and adjuvant treatment. Treatment complications can be reduced by referral to regional, high-volume pediatric thyroid centers.

Pediatric differentiated thyroid carcinoma: An update from the APSA Cancer Committee

BACKGROUND

Differentiated thyroid carcinomas (DTCs) are rare in young children but represent almost 10% of all malignancies diagnosed in older adolescents.

METHODS

This article reviews the recent literature describing surgical therapeutic approaches to pediatric DTC, associated complications, and long-term recurrence and survival outcomes.

RESULTS

Similar to adult thyroid cancers, pediatric DTCs are more common in females and are associated with thyroid nodules, family history of thyroid cancer, radiation exposure, iodine deficiency, autoimmune thyroid disease, and genetic syndromes. Management of thyroid cancers in children involves ultrasound imaging, fine needle aspiration, and surgical resection with treatment decisions based on clinical and radiological features, cytology and risk assessment.

CONCLUSIONS

Total thyroidectomy and compartment based resection of clinically involved lymph node basins form the cornerstone of treatment of DTC. There is an evolving literature regarding the use of molecular genetics to inform treatment strategies and the use of targeted therapies to treat iodine refractory and surgically unresectable progressive disease.

TYPE OF STUDY

Summary review.

LEVEL OF EVIDENCE

This is a review article of previously published Level 1-5 articles that includes expert opinion (Level 5).

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.

Clinicopathological Features Predict Outcomes in Patients with Radioiodine-Refractory Differentiated Thyroid Cancer Treated with Sorafenib: A Real-World Study

BACKGROUND

Because beneficial response and progression-free survival (PFS) were achieved by well-designed clinical trials with tyrosine kinase inhibitors (TKIs) in patients with progressive radioiodine-refractory differentiated thyroid cancer (RR-DTC), the overall survival (OS) and improvement of therapeutic outcomes in the real world have been anticipated.

SUBJECTS, MATERIALS, AND METHODS

This prospective, single-center, real-world study assessed the predictive significance of clinicopathological features on disease control rate (DCR), objective response rate (ORR), PFS, and OS in a cohort of 72 patients with progressive RR-DTC treated with sorafenib at an initial dose of 200 mg twice daily.

RESULTS

Disease control, objective response, and biochemical effectiveness were achieved in 73.3%, 21.7%, and 77.9% of patients, respectively. The median PFS and OS were 17.6 and 28.9 months, respectively. Multivariate analyses showed that hand-foot syndrome (HFS) was an independent predictor for better DCR and ORR, and ¹³¹ I-avidity for higher ORR. In univariate analyses, longer PFS and OS were observed in patients with Eastern Cooperative Oncology Group performance status (ECOG PS) ≤2, pathologically well DTC, lung-only metastasis, absence of bone metastasis, biochemically nonineffective response, HFS, or radiological disease control. In multivariate analyses, only well DTC and ECOG PS ≤2 remained as independent prognostic factors for more favorable PFS and OS, respectively, whereas the absence of bone metastasis and biochemically nonineffective response independently predicted superior PFS and OS.

CONCLUSION

This study demonstrated that clinicopathological features might play a vital role in predicting therapeutic outcomes in patients with progressive RR-DTC treated with sorafenib, warranting further optimization of candidates for TKIs.

IMPLICATIONS FOR PRACTICE

This prospective, single-center, real-world study was designed to investigate the significance of clinicopathological features in predicting response, progression-free survival, and overall survival in patients with progressive radioiodine-refractory differentiated thyroid cancer (DTC) treated with sorafenib. Multivariate analyses showed that hand-foot syndrome was an independent predictor for better response. Meanwhile, well DTC, Eastern Cooperative Oncology Group performance status ≤2, biochemically nonineffective response, and the absence of bone metastasis were independent prognostic factors for more favorable survival. This study demonstrated that clinicopathological features might play a vital role in predicting outcomes in sorafenib-treated patients with radioiodine-refractory DTC, warranting optimization of indications.

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.

Response to Lenvatinib in Children with Papillary Thyroid Carcinoma

BACKGROUND

Papillary thyroid carcinoma (PTC) is the most common thyroid malignancy in children and adolescents. Infrequently, children with PTC may present with or develop disease not amenable to surgery or radioactive iodine (RAI), and systemic therapy may be an option. Lenvatinib is an oral tyrosine kinase inhibitor that is approved by the Food and Drug Administration for the treatment of adults with locally recurrent or metastatic, progressive, RAI-refractory well-differentiated thyroid carcinoma. The effect of lenvatinib in children with PTC has not been reported.

PATIENT FINDINGS

Three children with metastatic PTC not amenable or refractory to RAI who responded to lenvatinib are reported. All of them developed respiratory distress requiring oxygen caused by extensive bilateral metastatic pulmonary disease. The first patient is a 14-year-old female who was initially treated with sorafenib for extensive PTC not amenable to upfront surgery or RAI. She had progressive pulmonary disease after five months, and was subsequently treated with oral lenvatinib (14 mg/m²/day). She was weaned to room air after eight weeks. The second patient is a 15-year-old male who was treated with lenvatinib (14 mg/m²/day) for iodine non-avid diffuse pulmonary disease after initial total thyroidectomy and cervical lymph node dissection. He was weaned off oxygen in six weeks. The third patient is a five-year-old male who was treated with lenvatinib (14 mg/m²/day) for pulmonary disease progression 24 months after treatment with total thyroidectomy, cervical lymph node dissection, and RAI treatment. He was weaned off oxygen one day after starting lenvatinib. Two of the patients required dose adjustments secondary to proteinuria. Otherwise, all patients tolerated lenvatinib well. The first two patients remained clinically stable on lenvatinib 23 months and 11 months after initiation of therapy, respectively, and the third patient transitioned to a tumor-specific targeted therapy after one month.

SUMMARY

Three pediatric patients are reported with metastatic PTC not amenable or refractory to RAI who achieved a response on lenvatinib.

CONCLUSION

Lenvatinib therapy is well tolerated and demonstrated clinical activity in children with advanced PTC. Lenvatinib should be considered in children with PTC that is refractory or not amenable to conventional management.

Sorafenib treatment for papillary thyroid carcinoma with diffuse lung metastases in a child with autism spectrum disorder: a case report

BACKGROUND

Pediatric papillary thyroid carcinoma frequently presents with lymph node involvement and distant metastases. Sorafenib, an oral multikinase inhibitor, has been used to treat radioactive iodine (RAI) therapy-refractory thyroid carcinoma in adults; however, pediatric experience is limited. Medical procedures and hospitalization for children with autism spectrum disorder may be challenging.

CASE PRESENTATION

An 11-year-old boy with autism spectrum disorder and moderate intellectual impairment presented with dyspnea on exertion with thyroid carcinoma and diffuses lung metastases. Total thyroidectomy and adjuvant RAI therapy is the standard treatment; however, the latter therapy was impractical because of his respiratory status and challenging behaviors. He was therefore started on sorafenib 200 mg/day (150 mg/m²/day) and this dosage was increased to 400 mg/day (300 mg/m²/day). The adverse effects were mild and tolerable. After administration of medication, his dyspnea improved and surgery was performed. We attempted to administer RAI therapy after surgery; however, we abandoned it because he had difficulty taking care of himself according to isolation room rules. Thyrotropin suppression therapy was therefore started and sorafenib treatment (400 mg/day) resumed. Follow-up imaging showed regression of pulmonary metastases. The metastases have remained stable for over 24 months on continuous sorafenib treatment without serious adverse events.

CONCLUSION

We inevitably used sorafenib as an alternative to standard therapy because of the patient's specific circumstances. Individualized strategies for pediatric cancer patients with autism spectrum disorder are needed.

Risk prediction in children and adults less than 45 years old with papillary thyroid cancer

The incidence of papillary thyroid cancer is increasing faster than any other cancer in young patients. The purpose of this review is to discuss the most recent determinants of risk of recurrence and compromised outcomes in this population. Areas covered: This review discusses the most updated data on patient age, including children and young adults, extent of disease and subsequent dynamic staging over time, molecular markers for disease aggressiveness, adequacy of surgical resection and surgeon volume, and novel therapies for advanced non-resectable disease as predictors of patient outcomes. Expert commentary: Young patients enjoy excellent outcomes, with long-term survivorship, but face higher risks of short-term complications and disease recurrence. Thoughtful evaluation of the extent of disease, tumor features associated with more aggressive behavior, the presence of locoregional or distant metastases, and an understanding of molecular changes in their tumors are important areas of consideration. High-volume surgeons should work collaboratively with endocrinologists, radiologists, and pathologists specializing in thyroid cancer to help patients achieve excellent outcomes. Emerging data challenging the status quo regarding the relative importance of patient age, tumor features, and dynamic risk-adjustment for overall prognosis of these patients will likely impact future care and staging systems.

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.

Phase 2 trial of sorafenib in children and young adults with refractory solid tumors: A report from the Children's Oncology Group

BACKGROUND

Sorafenib is an oral small molecule inhibitor of multiple kinases controlling tumor growth and angiogenesis. The purpose of the phase 2 study was to determine the response rate of sorafenib and gain further information on the associated toxicities, pharmacokinetics, and pharmacodynamics of sorafenib in children and young adults with relapsed or refractory tumors including rhabdomyosarcoma, Wilms tumor, hepatocellular carcinoma (HCC), and papillary thyroid carcinoma (PTC).

PROCEDURE

Sorafenib, 200 mg/m(2) /dose, was administered every 12 hr continuously for 28 day cycles using a two-stage design in two primary strata (rhabdomyosarcoma and Wilms tumor) and two secondary strata (HCC and PTC). Correlative studies in consenting patients included determination of sorafenib steady state trough concentrations and assessments of VEGF and sVEGFR2.

RESULTS

Twenty patients (median age of 11 years; range, 5-21) enrolled. No objective responses (RECIST) were observed in the 10 evaluable patients enrolled in each of the two primary disease strata of rhabdomyosarcoma and Wilms tumor. No patients with HCC or PTC were enrolled. Sorafenib was not associated with an excessive rate of dose-limiting toxicity (DLT). The mean ± SD steady state concentration during cycle 1 day 15 was 6.5 ± 3.9 μg/ml (n = 10).

CONCLUSIONS

Sorafenib was well tolerated in children at 200 mg/m(2) /dose twice daily on a continuous regimen with toxicity profile and steady state drug concentrations similar to those previously reported. Single agent sorafenib was inactive in children with recurrent or refractory rhabdomyosarcoma or Wilms tumor.

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.

Sorafenib for the treatment of thyroid cancer: an updated review

INTRODUCTION

Sorafenib (Nexavar) is an oral multi-kinase inhibitor targeting B-type Raf kinase (BRAF) (both wild type and BRAF(V600E)), VEGFR1, VEGFR2, VEGFR3, PDGFRβ and RET (also RET/PTC) influencing both differentiated thyroid cancer (DTC) cell proliferation and angiogenesis.

AREAS COVERED

Encouraging results achieved in numerous Phase II trials were confirmed in a Phase III study conducted in radioiodine-refractory DTC. Sorafenib compared to placebo significantly prolongs progression-free survival, 10.8 versus 5.8 months, respectively. However, its administration resulted mainly in disease stabilization. No complete remission was obtained in any study. Beneficial effects were also demonstrated for medullary and anaplastic thyroid cancer; however further studies fulfilling evidence based medicine criteria are necessary. Its toxicity profile is convergent with other VEGFR inhibitors. The most common treatment-related side-effects involve skin toxicity (predominantly hand-foot skin reaction, different rashes and alopecia), gastrointestinal disturbances (diarrhea, abdominal pain), constitutional adverse reactions (anorexia, weight loss, fatigue) and hypertension. Although most adverse reactions are manageable, > 50% of patients required dose reduction.

EXPERT OPINION

Sorafenib constitutes the first line treatment option in advanced, radioiodine-refractory DTC. However, there are still no data on its efficacy in patients progressed after another tyrosine kinase inhibitor. Other applications of the drug, such as use as adjuvant therapy to 131-I treatment, requires further studies.

Binding interaction of sorafenib with bovine serum albumin: Spectroscopic methodologies and molecular docking

The binding interaction of sorafenib with bovine serum albumin (BSA) was studied using fluorescence, circular dichrosim (CD) and molecular docking methods. The results revealed that there was a static quenching of BSA induced by sorafenib due to the formation of sorafenib-BSA complex. The binding constant and number of binding site of sorafenib with BSA under simulated physiological condition (pH=7.4) were 6.8×10(4) M(-1) and 1 at 310 K, respectively. Base on the sign and magnitude of the enthalpy and entropy changes (ΔH(0)=-72.2 kJ mol(-1) and ΔS(0)=-140.4J mol(-1) K(-1)) and the results of molecular docking, it could be suggested that the binding process of sorafenib and BSA was spontaneous and the main interaction forces of sorafenib with BSA were van der Waals force and hydrogen bonding interaction. From the results of site marker competitive experiments and molecular docking, it could be deduced that sorafenib was inserted into the subdomain IIA (site I) of BSA and leads to a slight change of the conformation of BSA. And, the significant change of conformation of sorafenib occurred in the binding process with BSA to increase the stability of the sorafenib-BSA system, implying that the flexibility of sorafenib played an important role in the binding process.

Response to sorafenib in a pediatric patient with papillary thyroid carcinoma with diffuse nodular pulmonary disease requiring mechanical ventilation

BACKGROUND

Papillary thyroid cancer (PTC) presents with local and distant metastases more frequently in children than in adults. However, hypoxemia secondary to pulmonary metastases has not been reported in the literature. Sorafenib is a small-molecule multikinase inhibitor used in radioactive iodine ((131)I)-refractive papillary thyroid carcinoma.

PATIENT FINDINGS

An eight-year-old boy presented with fever and hypoxemia and was found to have H1N1 viral pneumonia requiring mechanical ventilation and antiviral and glucocorticoid treatment. After initial improvement, he was readmitted one month later because of persistent hypoxemia. A high-resolution computed tomography of the chest and neck revealed multiple 1-4 mm nodules and necrotic lymph nodes on the right side of the neck. Left lung wedge resection and right deep cervical node biopsies were consistent with PTC. He underwent a total thyroidectomy with a central neck node dissection and postoperatively required prolonged mechanical ventilation. Due to the inability to be weaned from mechanical ventilation, treatment with sorafenib 200 mg daily (10 mg/kg/day, 250 mg/m(2)) was initiated. Eight days thereafter, ventilation support was discontinued and the child was extubated. However, he failed extubation secondary to supraglottic edema, and seven days later tracheostomy was performed. The dosage of sorafenib was increased to 200 mg twice daily (20 mg/kg/day, 500 mg/m(2)). After 52 days of therapy, a repeat computed tomography scan showed reduction in the lung nodule size to 1-2 mm. He underwent (131)I therapy 87 days after sorafenib was started. A post-treatment scan showed extensive uptake throughout the lungs and thyroid bed, supraclavicular nodes, and cervical nodes.

CONCLUSIONS

This is the first reported case of a pediatric patient with respiratory failure possibly secondary to diffuse micronodular PTC requiring mechanical ventilation and subsequent delay in definitive therapy. Sorafenib could be considered for gap therapy when (131)I therapy cannot be administered in a timely manner. Treatment with this multikinase inhibitor does not seem to adversely affect the uptake of (131)I in radiation-naïve patients.

Thyroid cancer in children and adolescents

PURPOSE OF REVIEW

Paediatric thyroid cancer is a rare disease, but its incidence is rising in recent reports. This review aims at integrating recent findings into the current optimal diagnostic and therapeutic approach.

RECENT FINDINGS

The causal relationship of differentiated thyroid cancer (DTC) to radiation exposure is increasingly unravelled. Research progressively uncovers the genetic basis, such as RET (rearranged during transfection)/papillary thyroid cancer (PTC) rearrangement and RET-mutations. Knowledge of oncogenic signalling pathways nowadays starts to help finetuning diagnosis, prognosis and treatment. This knowledge complements the current state-of-the-art of paediatric thyroid cancer treatment. In childhood, DTC presents at a more advanced stage and implies higher recurrence rates, recurrences often occurring decades later. Treatment should minimize not only these recurrences but also long-term treatment sequelae. Total thyroidectomy and central compartment dissection by a high-volume surgeon and radioactive iodine is the preferred approach for most children with DTC. For children with medullary thyroid cancer within the MEN2 framework, when possible, prophylactic thyroidectomy is performed. Unfortunately, frequently, the diagnosis is still made at a later stage, and then requires total thyroidectomy with dissection of the central compartment and the lateral neck, when involved.

SUMMARY

The management complexity, the essential long-term follow-up and the lifetime burden of eventual complications demands management of paediatric thyroid cancer by physicians with the highest expertise. In such hands, excellent results can be obtained.

The Use of Sorafenib in the Thyroid Cancer

There are not effective therapies for metastatic unresectable, non-RAI-avid thyroid carcinomas. Fortunately, thyroid carcinomas represent a promising paradigm for targeted therapy due to the presence of activing mutations of genes coding the kinase tyrosines which are involved in all functions of cancer cells (such as: growth or invasion). In this paper an efficacy and toxicity of sorafenib, one of the multi-kinase inhibitors in thyroid carcinomas treatment is presented.

Pediatric thyroid cancer

Thyroid cancer is an uncommon childhood malignancy that presents primarily in young children or adolescent females and may be related to radiation exposure or genetic predisposition. Gene alterations, such as RET mutation or RET/PTC rearrangement, are not uncommon. Recent studies have lead to an increased understanding of the role of these particular gene alterations in the diagnosis, prognosis, and treatment of thyroid cancer. Surgery remains the mainstay of treatment for thyroid cancer followed by radioactive iodine when appropriate. In patients with MEN2, prophylactic thyroidectomy is recommended, although a delay in the initial diagnosis is common. With early aggressive treatment and long-term follow-up, these patients generally have excellent outcomes. Recent research suggests potential usefulness of novel therapies directed at oncogenic signaling pathways, modulators of growth, angiogenesis inhibitors, immunomodulators, and gene therapy.

Approach to the patient with advanced differentiated thyroid cancer

Patients with advanced thyroid cancer may benefit from l-thyroxine treatment at doses that suppress serum TSH level, local treatment interventions, and radioiodine therapy. In those patients who are refractory to radioiodine therapy and in whom progressive disease has been documented, the efficacy of cytotoxic chemotherapy is poor. Encouraging results have been obtained with the use of kinase inhibitors that should be offered as first-line treatment, preferably in the context of a prospective trial.

[Refractory thyroid cancers]

Refractory thyroid cancers include medullary and differentiated cancers with locally advanced disease that is not amenable to surgery or with distant metastases, differentiated thyroid carcinomas being refractory to radio-iodine treatment and all anaplastic carcinomas. These carcinomas are rare, with an estimated incidence in France of 350 new cases per year. Their management may benefit from the TUTHYREF network. Kinase inhibitors inhibit kinases of the VEGF receptors, and this inhibits angiogenesis, and some of these agents also inhibit other kinases of the MAPkinase pathway. These inhibitors are effective in differentiated and medullary thyroid cancers, and induce a partial response or a long-term stabilisation in more than half of patients. Their toxicity is significant and these treatments should be given only to selected patients with locally advanced or metastatic disease, with progression or with clinical symptoms.

[Management of refractory thyroid cancers]

During the last two decades, the understanding of molecular biology of thyroid cancers has greatly improved, and this has permitted the development of novel therapeutic tools in patients with refractory disease. Kinase inhibitors inhibit kinases of the VEGF receptors, and by doing this inhibit angiogenesis, and some of these agents also inhibit other kinases of the Mitogen-Activated Protein kinases (MAPkinase) pathway. These inhibitors are effective in differentiated and medullary thyroid cancers, and induce a partial response or a long-term stabilisation in more than half of patients.

Targeted therapies for thyroid tumors

Systemic chemotherapies for advanced or metastatic thyroid carcinomas have been of only limited effectiveness. For patients with differentiated or medullary carcinomas unresponsive to conventional treatments, novel therapies are needed to improve disease outcomes. Multiple novel therapies primarily targeting angiogenesis have entered clinical trials for metastatic thyroid carcinoma. Partial response rates up to 30% have been reported in single-agent studies, but prolonged disease stabilization is more commonly observed. The most successful agents target the vascular endothelial growth factor receptors, with potential targets including the mutant kinases associated with papillary and medullary oncogenesis. Two drugs approved for other malignancies, sorafenib and sunitinib, have had promising preliminary results reported, and are being used selectively for patients who do not qualify for clinical trials. At least one randomized, placebo-controlled phase III trial has been successfully completed, showing improved progression-free survival in patients with advanced or metastatic medullary thyroid carcinoma treated with vandetanib. Randomized trials for other agents are currently underway. Treatment for patients with metastatic or advanced thyroid carcinoma now emphasizes clinical trial opportunities for novel agents with considerable promise. Alternative options now exist for use of tyrosine kinase inhibitors that are well tolerated and may prove worthy of regulatory approval for this disease.

Response to sorafenib at a low dose in patients with radioiodine-refractory pulmonary metastases from papillary thyroid carcinoma

BACKGROUND

Sorafenib has shown promise in the treatment of patients with advanced or metastatic thyroid carcinoma. However, the optimal dose has not been established and data on Chinese population are not available. We conducted a study to assess the responses to sorafenib at a low dose of 200 mg twice daily in patients with progressive radioiodine-refractory pulmonary metastases from papillary thyroid carcinoma (PTC).

PATIENTS AND METHODS

Eligible patients received sorafenib 200 mg orally twice daily. Responses were assessed using Response Evaluation Criteria in Solid Tumors and adverse events were assessed periodically. The end points included response rate and progression-free survival.

RESULTS

Nine patients with radioiodine-refractory PTC were enrolled in the study and treated for a minimum of 13 weeks. The objective partial response rate was 33%. The stable disease rate was 44%. The mean progression-free survival was 42 weeks (95% confidence interval, 29.5 to 53.9). Two patients showed disease progression, and one of them died at 4 months after beginning of treatment. There was a marked and rapid change in the serum thyroglobulin level after start of treatment, with a mean decrease of 60% within 12 weeks, consistent with radiographic findings. Although the types of toxicities were consistent with other sorafenib trials, their severity was relatively mild. None of the patients discontinued sorafenib or reduced their dose because of treatment-related adverse events.

CONCLUSION

Sorafenib at a dose of 200 mg twice daily has a potential therapeutic effect and is well tolerated in Chinese patients with PTC and radioiodine-refractory pulmonary metastases. Further study is warranted with a larger cohort of patients.

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.

Molecular targeted therapies for patients with refractory thyroid cancer

The recent availability of molecular targeted therapies leads to reconsideration of the treatment strategy in patients with distant metastases from differentiated thyroid carcinoma who are resistant to radioiodine therapy, and in patients with metastatic medullary thyroid carcinoma. In patients with progressive disease, treatment with kinase inhibitors should be offered, preferably in the context of a prospective trial.

Targeted therapy of thyroid cancer

Systemic chemotherapies for advanced or metastatic thyroid carcinomas have been of only limited effectiveness. For patients with differentiated or medullary carcinomas unresponsive to conventional treatments, novel therapies are needed to improve disease outcomes. Multiple novel therapies primarily targeting angiogenesis have entered clinical trials for metastatic thyroid carcinoma. Partial response rates up to 30% have been reported in single agent studies, but prolonged disease stabilization is more commonly seen. The most successful agents target the vascular endothelial growth factor receptors, with potential targets including the mutant kinases associated with papillary and medullary oncogenesis. Two drugs approved for other malignancies, sorafenib and sunitinib, have had promising preliminary results reported, and are being used selectively for patients who do not qualify for clinical trials. Additional agents targeting tumor vasculature, nuclear receptors, epigenetic abnormalities, and the immune response to neoplasia have also been investigated. Randomized trials for several agents are underway that may lead to eventual drug approval for thyroid cancer. Treatment for patients with metastatic or advanced thyroid carcinoma now emphasizes clinical trial opportunities for novel agents with considerable promise. Alternative options now exist for use of tyrosine kinase inhibitors that are well tolerated and may prove worthy of regulatory approval for this disease.

Molecularly targeted therapies for thyroid cancers

OBJECTIVE

To review the emerging evidence that therapies targeting key oncogenic and signaling kinases can be effective in treatment of advanced thyroid carcinomas.

METHODS

With use of PubMed and Google Scholar, a systematic review was performed of publications and scientific presentations summarizing pertinent clinical trials.

RESULTS

Studies of numerous inhibitors of BRAF, vascular endothelial growth factor receptor, and RET kinases indicate that patients with progressive or metastatic thyroid carcinoma can benefit from therapy with these novel agents. Severe toxic effects, however, are associated with these treatments, and caution is recommended in their use.

CONCLUSION

Further trials and identification of improved therapeutic targeting should lead to development of more effective treatments of thyroid carcinomas.

Tyrosine kinase inhibitors and the thyroid

Protein tyrosine kinase inhibitors (TKIs) have emerged as significant targets for novel cancer therapies. For patients with differentiated or medullary carcinomas unresponsive to conventional treatments, multiple novel therapies primarily targeting angiogenesis have entered clinical trials. Partial response rates up to 30% have been reported in single-agent studies, but prolonged disease stabilisation is more commonly seen. The most successful agents target the vascular endothelial growth factor receptors. Sorafenib and sunitinib have had promising preliminary results reported and are being used selectively for patients who do not qualify for clinical trials. Treatment for patients with metastatic or advanced thyroid carcinoma now emphasises clinical trial opportunities for novel agents with considerable promise. Adverse effects on thyroid function and thyroid hormone metabolism have also been seen with several TKIs, necessitating prospective thyroid function testing for all patients starting therapy.