Medullary thyroid cancer: management guidelines of the American Thyroid Association

Altered Epigenetic Mechanisms in Thyroid Cancer Subtypes

Thyroid carcinoma (TC) is the most frequent malignant neoplasm of the endocrine system. Molecular methods for diagnosis of invasive thyroid disease can be effectively adopted. Epigenetic factors play an important role in the diversity patterns of gene expression and the phenotypic and biological characteristics of TC subtypes. We aimed to review epigenetic changes in the main subtypes of TC, along with a presentation of the methods that have examined these changes, and active clinical trials for the treatment of advanced TCs targeting epigenetic changes. A literature analysis was performed in MEDLINE using PubMed, Elsevier, and Google Scholar for studies published up to 2016, using the keywords: "Epigenetic alterations" OR "Epigenetic changes", "thyroid cancers", "papillary thyroid cancer", "medullary thyroid cancer", "follicular thyroid cancer", and "anaplastic thyroid cancer", which resulted in 310 articles in English. All related abstracts were reviewed and studies were included that were published in English, had available full text, and determined the details of the methods and materials associated with the epigenetic patterns of TC and its subtypes (100 articles). Analysis of epigenetic alterations in TC subtypes helps to identify pathogenesis and can play an important role in the classification and diagnosis of tumors. Epigenetic mechanisms, especially aberrant methylation of DNA and microRNAs (miRs), are likely to play an important role in thyroid tumorigenesis. Further studies are required to elucidate the role of histone modification mechanisms in TC development.

p.Val804Met, the Most Frequent Pathogenic Mutation in RET, Confers a Very Low Lifetime Risk of Medullary Thyroid Cancer

CONTEXT

To date, penetrance figures for medullary thyroid cancer (MTC) for variants in rearranged during transfection (RET) have been estimated from families ascertained because of the presence of MTC.

OBJECTIVE

To gain estimates of penetrance, unbiased by ascertainment, we analyzed 61 RET mutations assigned as disease causing by the American Thyroid Association (ATA) in population whole-exome sequencing data.

DESIGN

For the 61 RET mutations, we used analyses of the observed allele frequencies in ∼51,000 individuals from the Exome Aggregation Consortium (ExAC) database that were not contributed via The Cancer Genome Atlas (TCGA; non-TCGA ExAC), assuming lifetime penetrance for MTC of 90%, 50%, and unbounded.

SETTING

Population-based.

RESULTS

Ten of 61 ATA disease-causing RET mutations were present in the non-TCGA ExAC population with observed frequency consistent with penetrance for MTC of >90%. For p.Val804Met, the lifetime penetrance for MTC, estimated from the allele frequency observed, was 4% [95% confidence interval (CI), 0.9% to 8%].

CONCLUSIONS

Based on penetrance analysis in carrier relatives of p.Val804Met-positive cases of MTC, p.Val804Met is currently understood to have high-lifetime penetrance for MTC (87% by age 70), albeit of later onset of MTC than other RET mutations. Given our unbiased estimate of penetrance for RET p.Val804Met of 4% (95% CI, 0.9% to 8%), the current recommendation by the ATA of prophylactic thyroidectomy as standard for all RET mutation carriers is likely inappropriate.

Multiple endocrine neoplasia 2 in Cyprus: evidence for a founder effect

PURPOSE

Multiple endocrine neoplasia type 2 (MEN2) affects patients with RET proto-oncogene mutations. This cohort study refers to patients who were diagnosed with familial medullary thyroid carcinoma (MTC) and underwent RET genetic testing in Cyprus between years 2002 and 2017.

METHODS AND PATIENTS

Forty patients underwent RET testing by Sanger sequencing of exons 10-11 and 13-16. Genotyping with STR genetic markers flanking the RET gene along with Y-chromosome genotyping and haplogroup assignment was also performed.

RESULTS

RET mutations were identified in 40 patients from 11 apparently unrelated Cypriot families and two non-familial sporadic cases. Nine probands (69.2%) were heterozygous for p.Cys618Arg, one (7.7%) for p.Cys634Phe, one (7.7%) for the somatic delE632-L633 and two (15.4%) for p.Met918Thr mutations. The mean age at MTC diagnosis of patients carrying p.Cys618Arg was 36.8 ± 14.2 years. The age of pheo diagnosis ranged from 26 to 43 years and appeared simultaneously with MTC in 5/36 (13.9%) cases. The high frequency of the p.Cys618Arg mutation suggested a possible ancestral mutational event. Haplotype analysis was performed in families with and without p.Cys618Arg. Six microsatellite markers covering the RET gene and neighboring regions identified one core haplotype associated with all patients carrying p.Cys618Arg mutation.

CONCLUSIONS

The mutation p.Cys618Arg is by far the most prevalent mutation in Cyprus followed by other reported mutations of variable clinical significance. The provided molecular evidence speculates p.Cys618Arg mutation as an ancestral mutation that has spread in Cyprus due to a possible founder effect.

The RET C611Y mutation causes MEN 2A and associated cutaneous

BACKGROUND

Cutaneous lichen amyloidosis (CLA) has been reported in some multiple endocrine neoplasia type 2A (MEN 2A) families affected by specific germline RET mutations C634F/G/R/W/Y or V804M, as a characteristic of the clinical manifestation in ‘MEN 2A with CLA’, one of four variants of MEN 2A, which was strictly located in the scapular region of the upper back.

PATIENT FINDINGS

This study reports a large south-eastern Chinese pedigree with 17 individuals carrying the MEN 2A-harboring germline C611Y (c.1832G>A) RET mutation by Sanger sequencing. One individual presented MEN 2A-related clinical features, including typical CLA in the interscapular region; another individual exhibited neurological pruritus and scratching in the upper back but lacked CLA skin lesions. Both subjects presented with CLA or pruritic symptoms several years before the onset of medullary thyroid carcinoma (MTC) and/or pheochromocytoma. The remaining 15 RET mutation carriers did not exhibit CLA; of these, one presented with MTC and pheochromocytoma, nine with MTC only, two with elevated serum calcitonin and three younger subjects with normal serum calcitonin levels. This family’s clinical data revealed a later diagnosis of MTC (mean age, 45.9 (range: 23–73) years), a lower penetrance of pheochromocytoma (2/17, 11.8%) and CLA (1/17, 5.9%). However, no hyperparathyroidism and Hirschsprung disease were reported in this family.

SUMMARY AND CONCLUSIONS

This is the first description of a family with MEN 2A-related CLA due to a germline RET C611Y mutation, which might exhibit a novel and diversified genotype–phenotype spectrum in MEN 2A.

65 YEARS OF THE DOUBLE HELIX: Endocrine tumour syndromes in children and adolescents

As medicine is poised to be transformed by incorporating genetic data in its daily practice, it is essential that clinicians familiarise themselves with the information that is now available from more than 50 years of genetic discoveries that continue unabated and increase by the day. Endocrinology has always stood at the forefront of what is called today 'precision medicine': genetic disorders of the pituitary and the adrenal glands were among the first to be molecularly elucidated in the 1980s. The discovery of two endocrine-related genes, GNAS and RET, both identified in the late 1980s, contributed greatly in the understanding of cancer and its progression. The use of RET mutation testing for the management of medullary thyroid cancer was among the first and one of most successful applications of genetics in informing clinical decisions in an individualised manner, in this case by preventing cancer or guiding the choice of tyrosine kinase inhibitors in cancer treatment. New information emerges every day in the genetics or system biology of endocrine disorders. This review goes over most of these discoveries and the known endocrine tumour syndromes. We cover key genetic developments for each disease and provide information that can be used by the clinician in daily practice.

Update on Multiple Endocrine Neoplasia Type 2: Focus on Medullary Thyroid Carcinoma

Multiple endocrine neoplasia type 2 (MEN2) is an autosomal dominant hereditary cancer syndrome caused by missense gain-of-function mutations in the RET proto-oncogene on chromosome 10. Specific RET mutations can predispose toward a particular phenotype and clinical course, with strong genotype–phenotype correlations. MEN2 is highly penetrant in medullary thyroid carcinoma (MTC), and it can be associated with bilateral pheochromocytoma and primary hyperparathyroidism. Two different clinical variants of MEN2 are known: MEN2A, which includes the familial subtype, and MEN2B. Treatment includes early thyroidectomy. Recommendations on the timing and extent of surgery are based on the RET mutation risk categories (moderate-, high-, or highest-risk) regarding the age of MTC onset. Early identification of patients with hereditary MTC has improved treatment outcomes. Previously, MTC was diagnosed based on clinical tumors; in contrast, with genetic screening, MTC can be diagnosed at preclinical disease states. This approach has resulted in a high cure rate and a much better prognosis for MTC. However, classification into one of the three RET mutation risk groups for predicting aggressiveness and prognosis has had limited impact. Increasing evidence has shown that patients with RET mutations in different risk classifications exhibit a broad spectrum of MTC aggressiveness during follow-up, with no relevant difference in survival. The specific germline activating mutation of the RET proto-oncogene appears to be the first determinant of the age of MTC onset, but, presumably, different regulatory events determine long-term tumor behavior.

Multiple Endocrine Neoplasia Syndromes from Genetic and Epigenetic Perspectives

Multiple endocrine neoplasia (MEN) syndromes are infrequent inherited disorders in which more than one endocrine glands develop noncancerous (benign) or cancerous (malignant) tumors or grow excessively without forming tumors. There are 3 famous and well-known forms of MEN syndromes (MEN 1, MEN 2A, and MEN 2B) and a newly documented one (MEN4). These syndromes are infrequent and occurred in all ages and both men and women. Usually, germ line mutations that can be resulted in neoplastic transformation of anterior pituitary, parathyroid glands, and pancreatic islets in addition to gastrointestinal tract can be an indicator for MEN1. The medullary thyroid cancer (MTC) in association with pheochromocytoma and/or multiple lesions of parathyroid glands with hyperparathyroidism can be pointer of MEN2 which can be subgrouped into the MEN 2A, MEN 2B, and familial MTC syndromes. There are no distinct biochemical markers that allow identification of familial versus nonfamilial forms of the tumors, but familial MTC usually happens at a younger age than sporadic MTC. The MEN1 gene (menin protein) is in charge of MEN 1 disease, CDNK1B for MEN 4, and RET proto-oncogene for MEN 2. The focus over the molecular targets can bring some hope for both diagnosis and management of MEN syndromes. In the current review, we look at this disease and responsible genes and their cell signaling pathway involved.

Pheochromocytoma and Paraganglioma in Neurofibromatosis type 1: frequent surgeries and cardiovascular crises indicate the need for screening

Background

Pheochromocytomas and Paragangliomas (PCC/PGL) are rare endocrine tumors that are mostly benign, but often hormone producing, causing significant morbidity and mortality due to excess catecholamine secretion and cardiovascular crises. It is estimated that 30% of PCC/PGL are due to germline mutations, including Neurofibromatosis type 1 (NF1). There is little published data describing the phenotype of NF1-associated PCC/PGL and there are no established recommendations for PCC/PGL screening in NF1.

Methods

We conducted a retrospective chart review of 17 patients with NF1-associated PCC/PGL who received care at a large academic referral center between the years of 1992-2016.

Results

Average age of diagnosis was 42 years old. Both genders were equally affected. Average tumor size was 3.9 cm. Nine patients were hypertensive; one had orthostatic hypotension; three had tachycardia; the remaining two patients had normal BP and HR. Most tumors were benign, unilateral adrenal tumors that were hormonally active. Two had metastatic disease. Six patients experienced cardiovascular crises; three of which occurred during elective surgeries for neurofibroma removal, and a fourth occurred during labor and delivery.

Conclusion

These data highlight the importance of screening for PCC/PGL in NF1, especially prior to surgical procedures and pregnancy, labor and delivery as these events can trigger a cardiovascular crisis. Screening is easily accomplished with plasma or urine free fractionated metanephrine levels.

Diagnostic value and lymph node metastasis prediction of a custom‑made panel (thyroline) in thyroid cancer

Differentiation of benign and malignant thyroid nodules is crucial for clinical management. Here, we explored the efficacy of next-generation sequencing (NGS) in predicting the classification of benign and malignant thyroid nodules and lymph node metastasis status, and simultaneously compared the results with ultrasound (US). Thyroline was designed to detect 15 target gene mutations and 2 fusions in 98 formalin-fixed, paraffin-embedded (FFPE) tissues, including those from 82 thyroid cancer (TC) patients and 16 patients with benign nodules. BRAF mutations were found in 57.69% of the papillary thyroid cancer (PTC) cases, while RET mutations were detected among all the medullary thyroid cancer (MTC) cases. Multiple mutations were positive but none showed dominance in anaplastic thyroid cancer (ATC) and follicular thyroid cancer (FTC). The sensitivity and specificity of NGS prediction in differentiation of benign and malignant thyroid nodules were 79.27 and 93.75%, respectively, and the positive predictive value (PPV) and negative predictive value (NPV) were 98.48 and 46.88%, respectively. The sensitivity and specificity of US were 76.83 and 6.25%, respectively, and the PPV and NPV were 80.77 and 5.00%, respectively. The area under curve (AUC) of NGS and US were 0.865 and 0.415, respectively. A total of 27 patients had ≥1 metastases to lymph nodes, 19 of which carried mutations, including BRAF, RET, NRAS, PIK3CA, TP53, CTNNB1 and PTEN. However, there was no correlation between the variant allele frequency of specific gene mutations and the number of metastatic lymph nodes. In conclusion, the prediction value of NGS was higher than the US-based Thyroid Imaging Reporting and Data System (TI-RADS). NGS is valuable for the accurate differentiation of benign and malignant thyroid nodules, and pathological subtypes in FFPE samples. The findings of the present study may pave the way for the application of NGS in analyzing fine-needle aspiration (FNA) biopsy samples.

Update on multiple endocrine neoplasia Type 1 and 2

Multiple endocrine neoplasia type 1 is a rare genetic syndrome, characterized by the co-occurrence, in the same individual or in related individuals of the same family, of hyperparathyroidism, duodenopancraetic neuroendocrine tumors, pituitary adenomas, adrenocortical tumors, and neuroendocrine tumors (carcinoids) in the thymus, the bronchi, or the stomach. Multiple endocrine neoplastic type 2 is a rare genetic syndrome, characterized by the familial occurrence of medullary thyroid carcinoma either isolated or associated with pheochromocytoma, primary hyperparathyroidism, or typical features (Marfanoid habitus, mucosal neuromas). Subjects with clinical MEN1 and those who carry a mutation in the MEN1 gene should be offered biochemical and imaging screening in order to detect tumors and evaluate their progression over time. Children with mutation in the RET gene should have prophylactic total thyroidectomy according to the category of aggressiveness of the detected mutation whereas those with clinical MEN2 should be operated on upon diagnosis. In MEN1 patients, special attention should be paid to evaluate the progression duodenopancraetic neuroendocrine tumors because of their malignant potential. Also, thymic neuroendocrine tumors should be detected as soon as possible because they represent the most lethal tumor. In MEN2, calcitonin and carcinoembryonic antigen (CEA) serve as excellent tumor markers for medullary thyroid carcinoma. Their preoperative levels are correlated with tumor size and predict postoperative cure. Moreover, calcitonin or CEA doubling time has important prognostic value. In both MEN syndromes, multidisciplinary approaches are very important in the care of affected patients. Moreover, those patients should be comprehensively informed and enabled to participate in the decision-making procedure. In addition to multidisciplinary approaches, every effort should be made to follow the recommendations and guidelines issued by national (the French Group of Endocrine Tumors) and international groups.

American Thyroid Association Guidelines and Statements: Past, Present, and Future

BACKGROUND

The American Thyroid Association (ATA) is continually striving to improve the quality of its publications. The ATA Guidelines Policies and Procedures Task Force was active during 2017. It recently recommended convening a formal standing committee to review and update policies and procedures for the development of clinical practice guidelines (CPGs) and Statements on an ongoing basis.

OBJECTIVE

This statement reviews the history of official ATA publications and discusses the challenges and findings identified by the Task Force. We also wish to present our "work in progress" and propose future directions for the new ATA Guidelines and Statements Committee (ATA GSC).

METHODS

Our Task Force reviewed the publication record of the ATA with respect to CPGs. We also reviewed existing ATA policies for CPGs and other official statements, examined policies of other organizations, solicited input from external experts and organizations, and convened five conference calls and two in-person meetings.

RESULTS

The ATA has a rich history of developing official publications that have been influential based on download and citation records as well as changes in practice trends. Key future issues to be further addressed by the ATA GSC include the following: (i) striving to improve the methodologic rigor of development of CPGs while balancing considerations of feasibility and timeliness and the role of transparently communicated expert opinion; (ii) formalizing a framework and process for development of new Statements; (iii) increasing stringency and transparency of management of competing interests of individuals being considered for CPG/Statement panel membership; (iv) encouraging consideration of equity and diversity in CPG/Statement development group composition; (v) increasing relevant stakeholder representation (including patient representatives) in development of CPGs/Statements; and (vi) expanding future guideline implementation strategies.

CONCLUSIONS

As shown by the completed literature search, the ATA has a long history of producing CPGs and Statements with global impact on informing clinical management, education, and research in thyroid diseases. The ATA remains committed to a process of continual improvement of its publications and to meeting stakeholder information needs. Based on the work of our Task Force, we have identified many elements that are needed to achieve this goal and areas of challenge for our new committee.

Incidence and prevalence of sporadic and hereditary MTC in Denmark 1960-2014: a nationwide study

Recent studies have shown a significant increase in the temporal trend of medullary thyroid carcinoma (MTC) incidence. However, it remains unknown to which extent sporadic medullary thyroid carcinoma (SMTC) and hereditary MTC (HMTC) affect the MTC incidence over time. We conducted a nationwide retrospective study using previously described RET and MTC cohorts combined with review of medical records, pedigree comparison and relevant nationwide registries. The study included 474 MTC patients diagnosed in Denmark between 1960 and 2014. In the nationwide period from 1997 to 2014, we recorded a mean age-standardized incidence of all MTC, SMTC and HMTC of 0.19, 0.13 and 0.06 per 100,000 per year, respectively. The average annual percentage change in incidence for all MTC, SMTC and HMTC were 1.0 (P = 0.542), 2.8 (P = 0.125) and -3.1 (P = 0.324), respectively. The corresponding figures for point prevalence at January 1, 2015 were 3.8, 2.5 and 1.3 per 100,000, respectively. The average annual percentage change in prevalence from 1998 to 2015 for all MTC, SMTC and HMTC was 2.8 (P < 0.001), 3.8 (P < 0.001) and 1.5 (P = 0.010), respectively. We found no significant change in the incidence of all MTC, SMTC and HMTC possibly due to our small sample size. However, due to an increasing trend in the incidence of all MTC and opposing trends of SMTC (increasing) and HMTC (decreasing) incidence, it seems plausible that an increase for all MTC seen by others may be driven by the SMTC group rather than the HMTC group.

Genotypic characteristics and their association with phenotypic characteristics of hereditary medullary thyroid carcinoma in Korea

BACKGROUND

Hereditary medullary thyroid carcinoma can present as a part of multiple endocrine neoplasia syndrome by rearranged during transfection gene mutation. We evaluated the prevalence of rearranged during transfection gene mutation in patients who have medullary thyroid carcinoma and the correlations of genotype with medullary thyroid carcinoma, pheochromocytoma, and hyperparathyroidism according to the revised American Thyroid Association risk level.

METHODS

A total of 331 patients were diagnosed with medullary thyroid carcinoma, 172 of whom were tested for the rearranged during transfection germline mutation by sequencing of exon 8, 10, 11, and 13-16. These patients were diagnosed during the years 1982-2012 at 2 Korean tertiary hospitals. Patients were analyzed according to the route of diagnosis (screened versus index cases) or the mutational site of rearranged during transfection gene (the American Thyroid Association risk group).

RESULTS

Rearranged during transfection mutation was found in 23.8% of patients tested, showing a decreasing trend with time. The most commonly mutated codon was codon 634 (37.1%), followed by codon 918 (14.3%). rearranged during transfection-positive patients were younger than rearranged during transfection-negative patients, although no other clinicopathologic characteristics differed. Screened cases were younger and had smaller tumors than index cases. Among rearranged during transfection-positive patients, pheochromocytoma manifested in 35.1% and hyperparathyroidism in 7.0%. Notably, pheochromocytoma and hyperparathyroidism emerged at any time after the diagnosis of medullary thyroid carcinoma. The American Thyroid Association risk-group analysis demonstrated that medullary thyroid carcinoma patients in the highest risk group were younger, had larger tumors, and higher disease-specific mortality. Similar results for pheochromocytoma were found, according to the American Thyroid Association risk group, although the results were not significant.

CONCLUSIONS

Korean patients who have medullary thyroid carcinoma showed a similar distribution of rearranged during transfection gene mutation with those in Western countries. The American Thyroid Association risk classification was shown to be useful for pheochromocytoma, as well as for medullary thyroid carcinoma. Familial screening for rearranged during transfection mutation and lifelong monitoring for associated pheochromocytoma should be emphasized in hereditary medullary thyroid carcinoma.

Quantitative Proteomics Analysis of Sporadic Medullary Thyroid Cancer Reveals FN1 as a Potential Novel Candidate Prognostic Biomarker

BACKGROUND

Sporadic medullary thyroid cancer (MTC) is a rare neuroendocrine tumor. Currently, although the diagnosis of sporadic MTC is relatively simple, the need to discover novel candidate prognostic biomarkers for sporadic MTC and investigate the underlying mechanism involved in this rare disease is urgent.

MATERIALS AND METHODS

We employed tandem mass tag-based liquid chromatography-mass spectrometry to identify and analyze differentially expressed proteins (DEPs) in sporadic MTC. Western blotting was used to validate the DEPs. Immunohistochemistry was performed to investigate FN1 and RPS6KA3 in an independent set of sporadic MTC tissues. Immunohistochemical data were analyzed by different statistical methods.

RESULTS

Three hundred eighty-eight DEPs were identified in mass spectrometry, mainly involved in the extracellular matrix, cytoskeletal remodeling, or oxidoreductase activity. Among them, THBS1, MMP9, FN1, RPS6KA3, SYT1, and carcinoembryonic antigen were successfully validated by Western blot. In addition, FN1 and RPS6KA3, enriched in extracellular matrix (ECM) remodeling and the mitogen-activated protein kinase (MAPK) signaling pathway, respectively, were investigated in an independent set of sporadic MTC tissues. Receiver-operator characteristic curve analysis showed that FN1 and RPS6KA3 can be used for discriminating sporadic MTC tumorous tissues from paired normal thyroid tissues, and the clinical biomarker calcitonin was positively correlated with FN1 and RPS6KA3 in tumorous tissues. Furthermore, the immunohistochemical scores of FN1 in tumorous tissue showed an inverse relationship with tumor classification, lymph node classification, and American Joint Committee on Cancer stage. Through univariate and multivariate analysis for progression-free survival, we also found that low FN1 expression in tumorous tissues was an independent worse prognostic factor for progression-free survival.

CONCLUSION

We identified that the pathophysiology of sporadic MTC involve numerous pathways, including the synaptic vesicle pathway, the MAPK signaling pathway, and the ECM remodeling pathway. Furthermore, our study also identified FN1 as novel prognostic biomarkers related to the pathophysiologic changes in sporadic MTC.

IMPLICATIONS FOR PRACTICE

Proteomic dissection and prognostic biomarkers are scarce in sporadic medullary thyroid cancer (MTC). This article reports the use of proteomics technology to comprehensively investigate the molecular mechanisms of sporadic MTC, which resulted in the identification of FN1 as a novel candidate prognostic biomarker.

Multiple Endocrine Neoplasia and Hyperparathyroid-Jaw Tumor Syndromes: Clinical Features, Genetics, and Surveillance Recommendations in Childhood

Children and adolescents who present with neuroendocrine tumors are at extremely high likelihood of having an underlying germline predisposition for the multiple endocrine neoplasia (MEN) syndromes, including MEN1, MEN2A and MEN2B, MEN4, and hyperparathyroid-jaw tumor (HPT-JT) syndromes. Each of these autosomal dominant syndromes results from a specific germline mutation in unique genes: MEN1 is due to pathogenic MEN1 variants (11q13), MEN2A and MEN2B are due to pathogenic RET variants (10q11.21), MEN4 is due to pathogenic CDKN1B variants (12p13.1), and the HPT-JT syndrome is due to pathogenic CDC73 variants (1q25). Although each of these genetic syndromes share the presence of neuroendocrine tumors, each syndrome has a slightly different tumor spectrum with specific surveillance recommendations based upon tumor penetrance, including the age and location for which specific tumor types most commonly present. Although the recommended surveillance strategies for each syndrome contain similar approaches, important differences do exist among them. Therefore, it is important for caregivers of children and adolescents with these syndromes to become familiar with the unique diagnostic criteria for each syndrome, and also to be aware of the specific tumor screening and prophylactic surgery recommendations for each syndrome. Clin Cancer Res; 23(13); e123-e32. ©2017 AACRSee all articles in the online-only CCR Pediatric Oncology Series.

Secondary and tertiary preventions of thyroid disease

INTRODUCTION

Secondary and tertiary preventions are concerned with the recognition of the disease process in a very early stage and delay in progression to complete disease and minimization of complications and the impact of illness.

METHODS

All articles related to secondary and tertiary prevention of thyroid diseases were reviewed. Using related key words, articles published between 2001 and 2015 were evaluated, categorized, and analyzed.

RESULTS

In secondary prevention, congenital hypothyroidism and subclinical hypo and hyperthyroidism are equally important. Routine screening of patients with multinodular goiter by either ultrasonography or calcitonin is a controversial issue, while calcitonin assessments in medullary cancer and RET in family members are recommended. Screening of thyroid disease in pregnancy is limited to those with risk factors. Views regarding the importance of thyroid autoimmunity in secondary prevention are also presented. In tertiary prevention, prescribing excessive doses of levothyroxine, in the elderly in particular and appropriate care of all patients to avoid progression and complications are the key issues.

CONCLUSION

Optimization of management of thyroid diseases requires timely screening, prevention of progression to more sever disease, optimal medical care, and avoidance of iatrogenic conditions.

Prophylactic thyroidectomy in children with multiple endocrine neoplasia type 2

BACKGROUND

In patients with multiple endocrine neoplasia type 2 (MEN2) syndrome, genetic testing offers early diagnosis, stratifies the risk of developing medullary thyroid cancer (MTC) and informs the timing of thyroidectomy. The efficacy of treatment, which depends on timely and safe surgery, is not well established.

METHODS

This was a retrospective review of diagnostic and clinicopathological outcomes of prophylactic thyroidectomy in children with MEN2 between 1995 and 2013 in the UK. American Thyroid Association (ATA) 2009 guidelines were used as a benchmark for adequate treatment.

RESULTS

Seventy-nine children from 16 centres underwent total thyroidectomy. Thirty-eight patients (48 per cent) underwent genetic testing and 36 (46 per cent) had an operation performed above the age recommended by the ATA 2009 guidelines; pathology showed MTC in 30 patients (38 per cent). Late surgery, above-normal preoperative calcitonin level and MTC on pathology correlated with late genetic testing. Twenty-five children had lymphadenectomy; these patients had more parathyroid glands excised (mean difference 0·61, 95 per cent c.i. 0·24 to 0·98; P = 0·001), and were more likely to have hypocalcaemia requiring medication (relative risk (RR) 3·12, 95 per cent c.i. 1·54 to 6·32; P = 0·002) and permanent hypoparathyroidism (RR 3·24, 1·29 to 8·11; P = 0·010) compared with those who underwent total thyroidectomy alone. Age did not influence the development of complications.

CONCLUSION

Late genetic testing may preclude age-appropriate surgery, increasing the risk of operating when MTC has already developed. Early genetic testing and age-appropriate surgery may help avoid unnecessary lymphadenectomy and improve outcomes.

Genomic sequencing identifies secondary findings in a cohort of parent study participants

PURPOSE

Clinically relevant secondary variants were identified in parents enrolled with a child with developmental delay and intellectual disability.

METHODS

Exome/genome sequencing and analysis of 789 "unaffected" parents was performed.

RESULTS

Pathogenic/likely pathogenic variants were identified in 21 genes within 25 individuals (3.2%), with 11 (1.4%) participants harboring variation in a gene defined as clinically actionable by the American College of Medical Genetics and Genomics. These 25 individuals self-reported either relevant clinical diagnoses (5); relevant family history or symptoms (13); or no relevant family history, symptoms, or clinical diagnoses (7). A limited carrier screen was performed yielding 15 variants in 48 (6.1%) parents. Parents were also analyzed as mate pairs (n = 365) to identify cases in which both parents were carriers for the same recessive disease, yielding three such cases (0.8%), two of which had children with the relevant recessive disease. Four participants had two findings (one carrier and one noncarrier variant). In total, 71 of the 789 enrolled parents (9.0%) received secondary findings.

CONCLUSION

We provide an overview of the rates and types of clinically relevant secondary findings, which may be useful in the design and implementation of research and clinical sequencing efforts to identify such findings.

Genetic diagnosis of a Chinese multiple endocrine neoplasia type 2A family through whole genome sequencing

Approximately 98% of patients with multiple endocrine neoplasia type 2A (MEN 2A) have an identifiable RET mutation. Prophylactic or early total thyroidectomy or pheochromocytoma/parathyroid removal in patients can be preventative or curative and has become standard management. The general strategy for RET screening on family members at risk is to sequence the most commonly affected exons and, if negative, to extend sequencing to additional exons. However, different families with MEN 2A due to the same RET mutation often have significant variability in the clinical exhibition of disease and aggressiveness of the MTC, which implies additional genetic loci exsit beyond RET coding region. Whole genome sequencing (WGS) greatly expands the breadth of screening from genes associated with a particular disease to the whole genome and, potentially, all the information that the genome contains about diseases or traits. This is presumably due to additive effect of disease modifying factors. In this study, we performed WGS on a typical Chinese MEN 2A proband and identified the pathogenic RET p.C634R mutation. We also identified several neutral variants within RET and pheochromocytoma-related genes. Moreover, we found several interesting structural variants including genetic deletions (RSPO1, OVCH2 and AP3S1, etc.) and fusion transcripts (FSIP1-BAZ2A, etc.).

Temporal Trends in the Presentation, Treatment, and Outcome of Medullary Thyroid Carcinoma: An Israeli Multicenter Study

BACKGROUND

The widespread use of neck sonography in recent years has led to a dramatic increase in the detection of thyroid cancer, accompanied by changes in the clinicopathologic features of the disease. However, small papillary carcinomas account for the bulk of this increase, while little is known about temporal changes in medullary thyroid carcinoma (MTC). The aim of this study was to evaluate trends in the presentation, treatment, and outcome of MTC.

METHODS

Patients treated for MTC at four medical centers in Israel were divided into three groups by year of diagnosis: 19811995 (period A), 1996-2005 (period B), and 2006-2016 (period C). Clinicopathologic and survival data were collected retrospectively from the medical files and compared between the groups.

RESULTS

The cohort included 182 patients (54.9% female) with a mean age of 49.2 ± 18.7 years: 43 (23.6%) diagnosed in period A, 54 (29.7%) in period B, and 85 (46.7%) in period C. No significant differences were found between the groups in primary tumor size (25.7 ± 18.9 mm, 26.6 ± 18 mm, and 23.7 ± 17.6 mm, respectively), proportion of micro-MTC (30.8%, 20.0%, and 25.3%, respectively), or TNM staging. Age at diagnosis significantly increased over time (38.7 ± 17.2 years, 51.7 ± 18.4 years, and 53.7 ± 17.7 years, respectively; p < 0.001), and the rate of familial MTC significantly decreased (41.9%, 14.8%, and 8.2%, respectively; p = 0.002). Although the implementation of cervical lymph node dissection increased (62.1%, 78.4%, and 85%, respectively; p = 0.01), detection of metastatic lymph nodes decreased from 88.9% in period A to 65.0% in periods B and C (p = 0.06). There was no difference between the groups in disease-specific survival or disease-free state at one year from diagnosis (37.5%, 43.1%, and 50%, respectively) and last follow-up (27%, 41.2%, and 48%, respectively). Similar findings on MTC presentation and outcomes were obtained when only patients with non-familial MTC were analyzed.

CONCLUSIONS

Unlike differentiated thyroid cancer, most of the presenting features of MTC have not changed over time. The most significant temporal change is a decreased rate of familial MTC. Despite more extensive surgery and the use of new treatment modalities in recent years, significant improvement in disease-related outcomes were not found.

Clinical characteristics and treatment of thyroid cancer in children and adolescents: a retrospective analysis of 83 patients

OBJECTIVE

To study the clinical characteristics, treatment, and prognosis of thyroid cancer in children and adolescents.

METHODS

We performed a retrospective analysis of clinical data from 83 cases of thyroid cancer in children and adolescents from January 1990 to December 2010. We compared extra-thyroid extension, lymph node metastasis, distant metastasis, and prognosis between pediatric patients ≤12 years of age (27 cases) and those >12 years of age (56 cases). All the patients agreed to undergo thyroidectomy and endocrine therapy, and the consent was obtained from parents or guardians.

RESULTS

Histopathology included papillary carcinoma in 67 cases, papillary carcinoma with partial follicular growth pattern in 1 case, papillary carcinoma with squamous metaplasia in 4 cases, follicular carcinoma in 7 cases, medullary carcinoma in 3 cases, and poorly differentiated carcinoma in 1 case. The total lymph node metastasis rate was 78.31%. Patients ≤12 years of age showed a higher rate of lymph node metastasis than the older group (92.59% vs. 71.43%, P=0.028). The incidence rate in females in the older group was higher than that in the younger group (80.36% vs. 59.26%, P=0.041). There were no significant differences in extra-thyroid extension, distant metastasis, survival rate, or recurrent disease between the two groups.

CONCLUSIONS

The lymph node metastasis of thyroid cancer is higher in patients ≤12 years of age than in those >12 years of age; the incidence rate is higher in females than in males. Childhood thyroid cancer has a good prognosis, surgery being the most effective treatment. Choosing a reasonable surgery method and comprehensive postoperative treatment can achieve a cure and satisfactory survival rate.

The Clinical Spectrum of Multiple Endocrine Neoplasia Type 2A with Cutaneous Lichen Amyloidosis in Ethnic Han Chinese

This study systematically reviewed previous literatures and analyzed the genotype-phenotype relationship between the multiple endocrine neoplasia type 2A (MEN 2A)-cutaneous lichen amyloidosis (CLA) and RET/OSMR/IL31RA mutations. RET/OSMR/IL31RA screening was performed on 8 RET-carriers from 3 independent Chinese MEN 2A families. Besides, 51 MEN 2A-CLA patients in 116 RET carriers from literatures were clustered and analyzed. Our results indicated that almost all MEN 2A-CLA patients exhibited CLA which was located in the scapular region and carried RET mutation at codon 634. Meanwhile, we firstly described MEN 2A-CLA here in Chinese Han patient with RET p.C634F mutation.

6. MEN syndromes

MEN1 and MEN2 are rare inherited cancer syndromes which express a variety of endocrine and nonendocrine tumors. The improved knowledge of molecular and clinical physiopathology of MEN syndromes, together with the availability of genetic testing, have led to earlier detection and intervention, with consequent reduction of mortality and morbidity for MEN-associated tumors. Genetic testing has gained a key role in the detection of asymptomatic patients harbouring mutations responsible for these syndrome, and allows institution of early and tailored intervention with a positive impact on the course of disease. Free full text available at www.tumorionline.it

Genetic and epigenetic background and protein expression profiles in relation to telomerase activation in medullary thyroid carcinoma

Medullary thyroid carcinomas (MTCs) exhibit telomerase activation in strong association with shorter patient survival. To understand the background of telomerase activation we quantified TERT copy numbers and TERT promoter methylation in 42 MTCs and normal thyroid references. Gain of TERT was demonstrated by quantitative PCR in 5/39 sporadic MTC. Increased methylation index (MetI) for CpG methylation at the TERT promoter was found in sporadic MTCs (P < 0.0001) and in MEN 2 associated MTCs (P = 0.011) vs. normal thyroid tissues. MetI correlated positively with TERT gene expression (r = 0.432, P = 0.006) and negatively with telomere length (r = −0.343, P = 0.032). MTC cases with MetI above the median of 52% had shorter survival as compared to cases with lower MetI (P = 0.005 for overall survival and P = 0.007 for disease-related survival). Protein expression profiles obtained by mass spectrometry were then studied in relation to telomerase activation in MTCs. Comparing protein levels between tumors defined by telomerase activity status, 240 proteins were associated with telomerase activity. Among telomerase activation positive cases a set of proteins was found to discriminate between MTCs with high and low TERT gene expression with enrichment for proteins involved in telomerase regulation. XRCC5 mRNA expression was found increased in MTCs vs. normal thyroid (P = 0.007). In conclusion the findings suggest a role for TERT copy number gain, TERT promoter methylation and XRCC5 expression in telomerase activation and telomere maintenance of MTC.

Apatinib-treated advanced medullary thyroid carcinoma: a case report

Medullary thyroid carcinoma (MTC) is a rare malignancy originating from calcitonin-producing parafollicular C cells of the thyroid. Neither radiotherapy nor chemotherapy has demonstrated durable objective responses in patients with advanced MTC. Vandetanib and cabozantinib are the 2 tyrosine kinase inhibitors recently approved by the US Food and Drug Administration, which are not affordable for most Chinese patients. Herein, we report a case of an MTC patient who responded to apatinib, a Chinese homemade tyrosine kinase inhibitor-targeted vascular endothelial growth factor receptor. The patient was treated with thyroid lobectomy but developed MTC with extensive metastasis. The levels of serum calcitonin and carcino-embryonic antigen were much higher than the normal range. Apatinib was given at a dose of 500 mg daily and adjusted according to tolerance. Sixteen weeks following apatinib administration, the patient achieved a partial response, which lasted more than 9 weeks. No severe toxicity or drug-related side effect was observed during the treatment. Therefore, apatinib could be a new option for the treatment of advanced MTC.

Medullary Thyroid Carcinoma With Exon 2 p.L56M RET Variant: Clinical Particular Features in Two Patients

RET (REarranged during Transfection) proto-oncogene variants are essential for the development of familial and sporadic forms of medullary thyroid carcinoma (MTC). The most frequent variants are usually located in exons 10, 11, and 13 through 16 of the RET gene. We report two cases of apparently sporadic MTC associated with the variant in exon 2 of RET gene. Patient 1, a 62-year old man who had undergone adrenalectomy for a 5 cm pheochromocytoma, was screened for type 2 multiple endocrine neoplasia (MEN 2) which showed elevated basal and post-intravenous calcium gluconate calcitonin levels. A fine needle aspiration biopsy (FNAB) confirmed the suspicion of MTC. The patient underwent total thyroidectomy and lymphadenectomy, and the histology showed C-cell hyperplasia with medullary microcarcinoma. Patient 2, a 57 years old woman, underwent total thyroidectomy for toxic multinodular goiter. Pre-operative FNAB had shown benign features, while basal calcitonin levels were only borderline increased. Final histology revealed medullary multifocal microcarcinoma. Genetic testing for RET protoncogene on DNA extracted from peripheral blood was performed in both patients and a missense variant on exon 2 (c.166C>A, p.L56M) was identified. To our knowledge, these are the first time two cases of MTC associated to RET p.L56M variant. Interestingly, one patient had also a pheochromocytoma suggesting a possible pathogenetic role of this variant in the genesis of MEN2A. While the association of this variant with MTC or MEN2A has been never reported, it has been described in association with Hirschsprung's disease.

Survival in patients with medullary thyroid cancer after less than the recommended initial operation

BACKGROUND AND OBJECTIVES

We aimed to evaluate the disease specific-survival (DSS) of patients with Medullary Thyroid Cancer (MTC) confined to the central neck based on the extent of the initial operation.

METHODS

This retrospective review of patients with MTC from the SEER registry from 2004 to 2012 excluded patients with lateral neck involvement or distant metastases.

RESULTS

The cohort (n = 766) included 85(11%) less than total thyroidectomies (TT), 212(28%) TT alone, and 469(61%) TT with lymph node excision. Mean tumor size was similar (2.2cm for <TT, 1.9 for TT alone, and 2.2 for TT with nodes, p=0.13). Patients receiving a TT with nodal excision were more likely to have multifocal tumors (8% <TT, 22% TT alone, and 27% TT with nodes, P < 0.001), and extrathyroidal extension (1% <TT, 4% TT alone, and 9% TT with nodes, P = 0.005). Even after controlling for significant predictors of DSS, extent of the initial operation did not predict survival (HR 0.28 for <TT, 95% CI 0.26-3.11 and HR 0.62 for TT alone, 95% CI 0.17-2.22 compared to TT with nodes, P = NS for all).

CONCLUSION

According to population-based SEER registry data, the extent of initial resection may not significantly change DSS in patients with MTC confined to the central neck.

Nationwide French Study of RET Variants Detected from 2003 to 2013 Suggests a Possible Influence of Polymorphisms as Modifiers

BACKGROUND

The presence of single nucleotide polymorphisms (SNPs) in the REarranged during Transfection (RET) gene has been investigated with regard to their potential role in the development or progression of medullary thyroid cancer or pheochromocytomas (PHEO) in patients with the multiple endocrine neoplasia type 2 (MEN2) syndrome. The aim of this study was to evaluate the spectrum of RET variants in France between 2003 and 2013, and to evaluate the impact of SNPs on the MEN2 A phenotype.

METHODS

In this retrospective cohort study, RET variants were screened in 5109 index cases, and RET pathogenic variants were screened in 2214 relatives. Exons 5, 8, 10, 11, 13, 14, 15, and 16 were characterized by Sanger sequencing. RET pathogenic variants, RET variants with unknown functional significance (VUS), and four RET SNP variants-G691S (rs1799939), L769L (rs1800861), S836S (rs1800862), and S904S (rs1800863)-were characterized and are reported in index cases. In silico analysis and classification following the recommendation of the American College of Medical Genetics and Genomics was performed for RET VUS. Each patient's age at the time of diagnosis, sex, and the endocrine neoplasias present at molecular diagnosis were recorded.

RESULTS

Twenty-six single VUS in RET without any well-defined risk profiles were found in 33 patients. Nine of these were considered probably pathogenic, 11 of uncertain significance, and six as probably benign. Three double pathogenic variants found in three patients were classified as pathogenic. A study of the entire cohort showed that patients carrying pathogenic variants or VUS in RET together with PHEO were diagnosed earlier than the others. The presence of the G691S SNP, or a combination of SNPs, increased the risk of developing PHEO but did not modify the date of the diagnosis. No association was found between SNPs and medullary thyroid cancer or hyperparathyroidism.

CONCLUSIONS

The findings propose a classification of 15 of the 26 VUS in RET without any well-defined risk profiles and suggest that the G691S SNP, or a combination of SNPs, may be associated with the development of PHEO.

Notch3 as a novel therapeutic target in metastatic medullary thyroid cancer

BACKGROUND

Medullary thyroid cancer portends poor survival once liver metastasis occurs. We hypothesize that Notch3 overexpression in medullary thyroid cancer liver metastasis will decrease proliferation and growth of the tumor.

METHODS

TT cells were modified genetically to overexpress Notch3 in the presence of doxycycline, creating the TT-Notch3 cell line. Mice were injected intrasplenically with either TT-Notch3 or control vector TT-TRE cells. Each cell line had 3 treatment groups: control with 12 weeks of standard chow, early DOX with doxycycline chow at day 0 and for 70 days thereafter, and late DOX with doxycycline chow at 8 weeks. Each animal underwent micro-computed tomography to evaluate for tumor formation and tumor quantification was performed. Animals were killed at 12 weeks, and the harvested liver was stained with Ki-67, hematoxylin and eosin, and Notch3.

RESULTS

Induction of Notch3 did not prevent formation of medullary thyroid cancer liver metastases as all mice in the early DOX group developed tumors. However, induction of Notch after medullary thyroid cancer liver tumor formation decreased tumor size, as seen on micro-computed tomography scans (late DOX group). This translated to a 37-fold decrease in tumor volume (P = .001). Notch3 overexpression also resulted in decreased Ki-67 index (P = .038). Moreover, Notch3 induction led to increased areas of neutrophil infiltration and necrosis on hematoxylin and eosin staining of the tumors CONCLUSION: Notch3 overexpression demonstrates an antiproliferative effect on established metastatic medullary thyroid cancer liver tumors and is a potential therapeutic target in treatment.

CXCR4/CXCR7/CXCL12 axis promotes an invasive phenotype in medullary thyroid carcinoma

Background:

Medullary thyroid carcinoma (MTC) is a rare and challenging endocrine malignancy. Once spread, the therapeutic options are limited and the outcome poor. For these patients, the identification of new druggable biological markers is of great importance. Here, we investigated the prognostic and biological role of the C-X-C chemokine receptors type 4 and 7 (CXCR4/7) in MTC.

Methods:

Eighty-six MTC and corresponding non-neoplastic thyroid specimens were immunohistochemically stained for CXCR4/7 using tissue microarray technology and expression levels correlated with clinicopathological variables. Medullary thyroid carcinoma cell line TT was treated with recombinant human SDF1α/CXCL12 (rh-SDF1α) and CXCR4 antagonists AMD3100 and WZ811. Changes in cell cycle activation, tumour cell invasiveness as well as changes in mRNA expression levels of genes associated with epithelial–mesenchymal transition (EMT) were investigated.

Results:

High CXCR4 expression was associated with large tumour size and metastatic disease. CXCR4 antagonists significantly reduced tumour cell invasiveness, while the treatment with rh-SDF1α stimulated invasive growth, caused cell cycle activation and induced EMT.

Conclusions:

The CXCR4/CXCR7/CXCL12 axis plays an important role in MTC. We provide first evidence that the chemokine receptors might serve as potential therapeutic targets in patients with advanced MTC and offer new valuable insight into the underlying molecular machinery of metastatic MTC.

Hypercalcemic Disorders in Children

Hypercalcemia is defined as a serum calcium concentration that is greater than two standard deviations above the normal mean, which in children may vary with age and sex, reflecting changes in the normal physiology at each developmental stage. Hypercalcemic disorders in children may present with hypotonia, poor feeding, vomiting, constipation, abdominal pain, lethargy, polyuria, dehydration, failure to thrive, and seizures. In severe cases renal failure, pancreatitis and reduced consciousness may also occur and older children and adolescents may present with psychiatric symptoms. The causes of hypercalcemia in children can be classified as parathyroid hormone (PTH)-dependent or PTH-independent, and may be congenital or acquired. PTH-independent hypercalcemia, ie, hypercalcemia associated with a suppressed PTH, is commoner in children than PTH-dependent hypercalcemia. Acquired causes of PTH-independent hypercalcemia in children include hypervitaminosis; granulomatous disorders, and endocrinopathies. Congenital syndromes associated with PTH-independent hypercalcemia include idiopathic infantile hypercalcemia (IIH), William's syndrome, and inborn errors of metabolism. PTH-dependent hypercalcemia is usually caused by parathyroid tumors, which may give rise to primary hyperparathyroidism (PHPT) or tertiary hyperparathyroidism, which usually arises in association with chronic renal failure and in the treatment of hypophosphatemic rickets. Acquired causes of PTH-dependent hypercalcemia in neonates include maternal hypocalcemia and extracorporeal membrane oxygenation. PHPT usually occurs as an isolated nonsyndromic and nonhereditary endocrinopathy, but may also occur as a hereditary hypercalcemic disorder such as familial hypocalciuric hypercalcemia, neonatal severe primary hyperparathyroidism, and familial isolated primary hyperparathyroidism, and less commonly, as part of inherited complex syndromic disorders such as multiple endocrine neoplasia (MEN). Advances in identifying the genetic causes have resulted in increased understanding of the underlying biological pathways and improvements in diagnosis. The management of symptomatic hypercalcemia includes interventions such as fluids, antiresorptive medications, and parathyroid surgery. This article presents a clinical, biochemical, and genetic approach to investigating the causes of pediatric hypercalcemia. © 2017 American Society for Bone and Mineral Research.

National Trends in the Surgical Treatment of Non-advanced Medullary Thyroid Cancer (MTC): An Evaluation of Adherence with the 2009 American Thyroid Association Guidelines

BACKGROUND

Medullary thyroid cancer (MTC) represents the third most common type of thyroid cancer, and the prognosis depends on the stage of the disease at diagnosis and completeness of tumor resection. In 2009, the American Thyroid Association (ATA) published guidelines with evidence-based recommendations for the treatment of MTC. This study aimed to determine national adherence rates of the treatment according to the ATA guidelines specific for MTC.

METHODS

Patients diagnosed with MTC from 2004 to 2013 were identified from the National Cancer Database. Guideline adherence rates for the treatment of MTC before and after the publication of ATA guidelines were analyzed and compared to determine patient and clinical variables that affected treatment.

RESULTS

A total of 3693 patients diagnosed with MTC were identified. We found 60.3 % of the patients had localized MTC and 39.7 % had regional metastases. Older age, female sex and having Medicaid or being uninsured were directly correlated with more advanced disease upon diagnosis (p < 0.001). Overall, a greater proportion of patients received care in accordance with the recommendations following the ATA guidelines' publication in 2009: 61.4 % of patients treated between 2004 and 2008 versus 66.8 % of patients treated between 2009 and 2013 received care in accordance with the recommendations (p < 0.01). Factors such as older age, African American race, localized disease at diagnosis, lower estimated median zip code household income and being treated in a community versus an academic hospital were associated with a lower likelihood of receiving care in accordance with the guidelines.

CONCLUSION

Adherence rates to the ATA recommendations for the treatment of MTC increased modestly following the publication of guidelines in 2009 with the largest increase seen in community hospitals. Being older, African American, diagnosed with localized disease and treated in a community hospital rather than in an academic institution was correlated with a lower likelihood of receiving treatment in accordance with the guidelines. Efforts should be made to continuously increase the adherence rates to the MTC ATA guidelines and to decrease socioeconomic disparities that continue to exist in the treatment of MTC.

Maternal and obstetrical outcome in 35 cases of well-differentiated thyroid carcinoma during pregnancy

OBJECTIVES/HYPOTHESIS

Thyroid cancer, with 6% to 10% of cancer diagnoses, is one of the most common malignancies during pregnancy. Its treatment poses a risk for the pregnancy, as the thyroid gland plays a crucial role in the evolution of pregnancy. The aim of this study is to evaluate treatment of primary well-differentiated thyroid carcinoma during pregnancy and fetal and maternal outcomes.

STUDY DESIGN

This is an international cohort study.

METHODS

Primary thyroid cancer patients were identified from the database of the International Network on Cancer, Infertility, and Pregnancy registration study. Data on histopathological characteristics, diagnostic and therapeutic interventions, outcome (obstetrical, neonatal, and maternal) and maternal follow-up were analyzed.

RESULTS

Thirty-five patients with well-differentiated thyroid carcinoma were eligible. All 35 patients underwent surgery, 29 (83%) of which during pregnancy. Procedures during pregnancy were mainly total thyroidectomies (n = 24). The median number of days between diagnosis and surgical treatment was different between the groups with surgery during and after pregnancy (27 vs. 139 days, P < .001). Both maternal and neonatal outcomes were uncomplicated, regardless of gestational age during surgery.

CONCLUSIONS

Well-differentiated thyroid carcinoma diagnosed during pregnancy has a favorable outcome for both mother and child. Surgical management during pregnancy has no negative impact on the pregnancy regardless of the trimester at the time of surgery. However, the potential negative effects of thyroid surgery early in pregnancy demand management of these patients in an experienced multidisciplinary team to provide the best possible care for these patients and their unborn babies.

LEVEL OF EVIDENCE

4. Laryngoscope, 128:1493-1500, 2018.

Predictive and prognostic value of 18F-DOPA PET/CT in patients affected by recurrent medullary carcinoma of the thyroid

INTRODUCTION

Medullary thyroid carcinoma (MTC) is a malignancy accounting for about 5-8% of thyroid cancers. Serum calcitonin and carcinoembryonic antigen (CEA) levels are widely used to monitor disease progression. However, prognostic factors able to predict outcomes are highly desirable. We, therefore, aimed to assess the prognostic role of ¹⁸F-DOPA PET/CT in patients with recurrent MTC.

MATERIALS AND METHODS

60 patients (mean age 64 ± 13 years, range 44-82) with recurrent MTC were eligible from a multicenter database. All patients underwent a restaging ¹⁸F-DOPA PET/CT, performed at least 6 months after surgery. CEA/calcitonin levels, local recurrences, nodal involvement and metastases at PET/CT were recorded. SUVmax, SUVmean (also normalized to mediastinal uptake) and metabolic tumor volume were automatically calculated for each lesion, by placing a volume of interest around the lesion with 40% of peak activity as threshold for the automatic contouring. The patients were clinically and radiologically followed up for 21 ± 11 months. Rate of progression-free survival (PFS), disease-specific survival (DSS) and incremental prognostic value of ¹⁸F-DOPA PET/CT over conventional imaging modalities were assessed by Kaplan-Meier curves and Log-Rank test. Cox regression univariate and multivariate analyses were performed for assessing predictors of prognosis.

RESULTS

¹⁸F-DOPA PET/CT showed abnormal findings in 27 patients (45%) and resulted unremarkable in 33 (55%). PFS was significantly longer in patients with an unremarkable PET/CT scan (p = 0.018). Similarly, an unremarkable PET/CT study was associated with a significantly longer DSS (p = 0.04). ¹⁸F-DOPA PET/CT added prognostic value over other imaging modalities both for PFS and for DSS (p < 0.001 and p = 0.012, respectively). Neither semiquantitative PET parameters nor clinical or laboratory data were predictive of a worse PFS and DSS in patients with recurrent MTC.

CONCLUSION

¹⁸F-DOPA PET/CT scan has an important prognostic value in predicting disease progression and mortality rate.

A large Chinese pedigree of multiple endocrine neoplasia type 2A with a novel C634Y/D707E germline mutation in RET exon 11

The present study identified the clinical features of the largest multiple endocrine neoplasia type 2 (MEN2) A pedigree from China, with a novel double missense rearranged during transfection (RET) mutation (C634Y/D707E). To the best of our knowledge, the D707E mutation has not been identified to date. In the present study, a total of 101 family members who originated from a large pedigree (134 members in total) underwent RET mutation screening by next-generation sequencing and polymerase chain reaction (PCR) amplification, followed by direct bidirectional DNA sequencing. The clinical features of this pedigree were carefully reviewed retrospectively, and statistical analyses were conducted using SPSS software. A total of 33 (32.67%) carriers were identified to exhibit the C634Y/D707E RET germline mutation. The mean age of the patients with medullary thyroid carcinoma (MTC) identified by RET screening was 38.4±16.5 years (n=11; range, 14–65 years). Only 4 patients with pheochromocytoma with a median age of 37 years were identified. No hyperparathyroidism was diagnosed. Persistent or recurrent disease developed in the patients of the present study who underwent inappropriate initial thyroid surgeries that were performed in previous decades (III10, III23, III24, III27 and IV46, as they had undergone two surgeries prior to the present study). A total of 66.70% (6/9) of patients, following thyroidectomy, continued to develop persistent or recurrent disease during the present screening study. In total, 3 patients succumbed to MTC or distant metastasis in the present study. The increase in carcinoembryonic antigen (CEA) levels correlated with the increase in basal serum calcitonin (Ct) levels according to Pearson correlation analysis in patients with MTC without surgery. Ct and CEA levels were also significantly correlated with tumor volumes. To the best of our knowledge, the present study is the first to identify a novel double RET missense mutation in the largest MEN2A pedigree from China. Additional in-depth study is necessary to elucidate the molecular mechanisms of the D707E mutation and its potential joint effects with the other C634Y mutation in the pedigree of the present study.

Calcitonin receptor expression in medullary thyroid carcinoma

Background

Calcitonin expression is a well-established marker for medullary thyroid carcinoma (MTC); yet the role of calcitonin receptor (CTR), its seven-transmembrane G-protein coupled receptor, remains to be established in C-cells derived thyroid tumors. The aim of this work was to investigate CTR expression in MTC and to correlate such expression with clinicopathological features in order to evaluate its possible role as a prognostic indicator of disease aggressiveness and outcome.

Methods

Calcitonin receptor expression was analyzed in a series of 75 MTCs by immunohistochemistry, and by qPCR mRNA quantification in specimens from four patients. Statistical tests were used to evaluate the correlation between CTR expression and the clinicopathological and molecular characteristics of patients and tumors.

Results

Calcitonin receptor expression was detected in 62 out of 75 samples (82.7%), whereas 13 of the 75 samples (17.3%) were completely negative. CTR expression was significantly associated with expression of cytoplasmatic phosphatase and tensin homologue deleted on chromosome 10 and osteopontin, as well as with wild type RET/RAS genes and absence of tumor stroma, suggesting that CTR expression do not associate with clinicopathological signs of worse prognosis.

Discussion

Calcitonin receptor expression appears to be associated in MTC with more differentiated status of the neoplastic cells.

United States and European Multicenter Prospective Study for the Analytical Performance and Clinical Validation of a Novel Sensitive Fully Automated Immunoassay for Calcitonin

BACKGROUND

The objective of this study is the validation and proof of clinical relevance of a novel electrochemiluminescence immunoassay (ECLIA) for the determination of serum calcitonin (CT) in patients with medullary thyroid carcinoma (MTC) and in different diseases of the thyroid and of calcium homeostasis.

METHODS

This was a multicenter prospective study on basal serum CT concentrations performed in 9 US and European referral institutions. In addition, stimulated CT concentrations were measured in 50 healthy volunteers after intravenous calcium administration (2.5 mg/kg bodyweight).

RESULTS

In total, 1929 patients and healthy controls were included. Limits of blank, detection, and quantification for the ECLIA were 0.3, 0.5, and 1 ng/L, respectively. Highest intra- and interassay coefficients of variation were 7.4% (CT concentration, 0.8 ng/L) and 7.0% (1.1 ng/L), respectively. Medians (interval) of serum CT concentrations in 783 healthy controls were 0.8 ng/L (&lt;0.5–12.7) and 3 ng/L (&lt;0.5–18) for females and males, respectively (97.5th percentile, 6.8 and 11.6 ng/L, respectively). Diagnostic sensitivity and specificity were 100%/97.1% and 96.2%/96.4%, for female/males, respectively. Patients (male/female) with primary hyperparathyroidism, renal failure, and neuroendocrine tumors showed CT concentrations &gt;97.5th percentile in 33%/4.7%, 18.5%/10%, and 8.3%/12%, females/males, respectively. Peak serum CT concentrations were reached 2 min after calcium administration (161.7 and 111.8 ng/L in males and females, respectively; P &lt; 0.001).

CONCLUSIONS

Excellent analytical performance, low interindividual variability, and low impact of confounders for increased CT concentrations in non-MTC patients indicate that the investigated assay has appropriate clinical utility. Calcium-stimulated CT results suggest good test applicability owing to low interindividual variability.

Plasma Calcitonin Levels and miRNA323 Expression in Medullary Thyroid Carcinoma Patients with or without RET Mutation

Background: Medullary thyroid cancer (MTC) is an endocrine tumor featuring parafollicular or C-cell differentiation, with calcitonin as a specific biomarker in MTC diagnosis. Germline mutations in the RET proto-oncogene are considered responsible for its familial occurrence and somatic mutations can cause sporadic lesions. MicroRNAs can act as oncogenes or tumor suppressors by inhibiting the expression of target genes.. The aim of this study was to investigate relationships between plasma levels of calcitonin and miRNA323 expression in MTC patients with or without RET mutation. Methods: In this cross-sectional study, MTC lesions (based on pathological confirmation) were investigated. Genomic DNA was extracted and Exons 10 and 11 of RET were genotyped using PCR-sequencing. Division was into two groups of 43 cases each with or without mutation. Plasma levels of calcitonin were determined in both. Results: miRNA323 was measured using real-time-PCR. After performing normality tests, independent T-tests and Mann Whitney tests were used for the statistical comparison of parametric and nonparametric data, respectively. Plasma levels of calcitonin were significantly higher in MTC cases without a RET mutation compared to those with a mutation. Conclusion: There was no significant difference between the two groups regarding the expression of miRNA323 so that this parameter could not be used as a bio-index germ line mutations in MTCs. However, determination of calcitonin levels in plasma might be helpful in this regard.

Current Advances in Thyroid Cancer Management. Are We Ready for the Epidemic Rise of Diagnoses?

A rising incidence of thyroid cancers (TCs) mainly small tumors, observed during recent years, lead to many controversies regarding treatment strategies. TCs represent a distinct molecular background and clinical outcome. Although in most cases TCs are characterized by a good prognosis, there are some aggressive forms, which do not respond to standard treatment. There are still some questions, which have to be resolved to avoid dangerous simplifications in the clinical management. In this article, we focused on the current advantages in preoperative molecular diagnostic tests and histopathological examination including noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). We discussed the controversies regarding the extent of thyroid surgery and adjuvant radioiodine therapy, as well as new treatment modalities for radioiodine-refractory differentiated thyroid cancer (RR-DTC). Considering medullary thyroid cancer (MTC), we analyzed a clinical management based on histopathology and RET (ret proto-oncogene) mutation genotype, disease follow-up with a special attention to serum calcitonin doubling time as an important prognostic marker, and targeted therapy applied in advanced MTC. In addition, we provided some data regarding anaplastic thyroid cancer (ATC), a highly lethal neoplasm, which lead to death in nearly 100% of patients due to the lack of effective treatment options.

177Lu Labeled Cyclic Minigastrin Analogues with Therapeutic Activity in CCK2R Expressing Tumors: Preclinical Evaluation of a Kit Formulation

Minigastrin (MG) analogues specifically target cholecystokinin-2 receptors (CCK2R) expressed in different tumors and enable targeted radiotherapy of advanced and disseminated disease when radiolabeled with a beta emitter such as ¹⁷⁷Lu. Especially truncated MG analogues missing the penta-Glu sequence are associated with low kidney retention and seem therefore most promising for therapeutic use. Based on [d-Glu¹,desGlu^2-6]MG (MG11) we have designed the two cyclic MG analogues cyclo^1,9[γ-d-Glu¹,desGlu^2-6,d-Lys⁹]MG (cyclo-MG1) and cyclo^1,9[γ-d-Glu¹,desGlu^2-6,d-Lys⁹,Nle¹¹]MG (cyclo-MG2). In the present work we have developed and preclinically evaluated a pharmaceutical kit formulation for the labeling with ¹⁷⁷Lu of the two DOTA-conjugated cyclic MG analogues. The stability of the kits during storage as well as the stability of the radiolabeled peptides was investigated. A cell line stably transfected with human CCK2R and a control cell line without receptor expression were used for in vitro and in vivo studies with the radioligands prepared from kit formulations. In terms of stability ¹⁷⁷Lu-DOTA-cyclo-MG2 showed advantages over ¹⁷⁷Lu-DOTA-cyclo-MG1. Still, for both radioligands a high receptor-mediated cell uptake and favorable pharmacokinetic profile combining receptor-specific tumor uptake with low unspecific tissue uptake and low kidney retention were confirmed. Investigating the therapy efficacy and treatment toxicity in xenografted BALB/c nude mice a receptor-specific and comparable therapeutic effect could be demonstrated for both radioligands. A 1.7- to 2.6-fold increase in tumor volume doubling time was observed for receptor-positive tumors in treated versus untreated animals, which was 39-73% higher when compared to receptor-negative tumors. The treatment was connected with transient bone marrow toxicity and minor signs of kidney toxicity. All together the obtained results support further studies for the clinical translation of this new therapeutic approach.

Medullary Thyroid Carcinoma in MEN2A: ATA Moderate- or High-Risk RET Mutations Do Not Predict Disease Aggressiveness

CONTEXT

High-risk RET mutations (codon 634) are associated with earlier development of medullary thyroid carcinoma (MTC) and presumed increased aggressiveness compared with moderate-risk RET mutations.

OBJECTIVE

To determine whether high-risk RET mutations are more aggressive.

DESIGN

Retrospective cohort study using institutional multiple endocrine neoplasia type 2 registry.

SETTING

Tertiary cancer care center.

PATIENTS

Patients with MTC and moderate- or high-risk germline RET mutation.

INTERVENTION

None (observational study).

MAIN OUTCOME MEASURES

Proxies for aggressiveness were overall survival (OS) and time to distant metastatic disease (DMD).

RESULTS

A total of 127 moderate-risk and 135 high-risk patients were included (n = 262). Median age at diagnosis was 42.3 years (range, 6.4 to 86.4 years; mean, 41.6 years) for moderate-risk mutations and 23.0 years (range, 3.7 to 66.8 years; mean, 25.6 years) for high-risk mutations (P < 0.0001). Moderate-risk patients had more T3/T4 tumors at diagnosis (P = 0.03), but there was no significant difference for N or M stage and no significant difference in OS (P = 0.40). From multivariable analysis for OS, increasing age [hazard ratio (HR), 1.05/y; 95% confidence interval (CI), 1.03 to 1.08], T3/T4 tumor (HR, 2.73; 95% CI, 1.22 to 6.11), and M1 status at diagnosis (HR, 3.93; 95% CI, 1.61 to 9.59) were significantly associated with worse OS but high-risk mutation was not (P = 0.40). No significant difference was observed for development of DMD (P = 0.33). From multivariable analysis for DMD, only N1 status at diagnosis was significant (HR, 2.10; 95% CI, 1.03 to 4.27).

CONCLUSIONS

Patients with high- and moderate-risk RET mutations had similar OS and development of DMD after MTC diagnosis and therefore similarly aggressive clinical courses. High-risk connotes increased disease aggressiveness; thus, future guidelines should consider RET mutation classification by disease onset (early vs late) rather than by risk (high vs moderate).

PROGNOSTIC VARIABLES AFFECTING PRIMARY TREATMENT OUTCOME FOR MEDULLARY THYROID CANCER

OBJECTIVE

Identifying prognostic risk factors and determining the efficacy of common surgical treatments is critical to determine optimal treatment strategies for patients with medullary thyroid carcinoma (MTC). The objective of this study was to review a contemporary institutional experience with MTC primary treatment with 2 goals: to identify prognostic factors that impact survival and to study the effect of neck dissection on those outcomes.

METHODS

This study was a retrospective case series of patients with MTC who underwent at least a total thyroidectomy with curative intent. Clinical parameters including tumor and nodal staging with corresponding pathology findings were identified. Survival endpoints included overall survival, disease-free survival, and biochemical cure.

RESULTS

Sixty-seven patients were included. The majority presented with early T-stage disease. Fifty (76%) patients were N0 at presentation. Seventeen (24%) had some evidence of neck disease on clinical examination or imaging. Forty (71%) achieved biochemical cure, and the 5-year biochemical recurrence-free survival for those cases was 86.5%. Among patients who had successful resection of all gross disease, 92% had no evidence of structural disease at 5 years. Overall survival was 91% at 5 years. Increased pre-operative calcitonin (Ct) level, primary tumor size, extrathyroidal extension, and neck metastases decrease the rate of biochemical cure. Larger tumor size increases the risk of structural disease recurrence and biochemical relapse after initial cure. The presence and number of neck metastases correlate with biochemical relapse. The presence of lateral neck nodes (pN1b) does not have different survival implications than centrally confined disease (pN1a).

CONCLUSION

This study shows increasing tumor size, increased Ct level, and cervical metastases are poor prognostic factors. Patients with large tumors, high Ct level, or unfavorable pathologic findings may warrant more aggressive initial treatment, although limitations of the study prevent any conclusion regarding the effect of neck dissection.

ABBREVIATIONS

ATA = American Thyroid Association BRFS = biochemical recurrence-free survival CND = central neck dissection Ct = calcitonin DFS = disease-free survival MTC = medullary thyroid carcinoma OR = odds ratio OS = overall survival pCND = prophylactic CND.

Risk Profile of the RET A883F Germline Mutation: An International Collaborative Study

CONTEXT

The A883F germline mutation of the rearranged during transfection (RET) proto-oncogene causes multiple endocrine neoplasia 2B. In the revised American Thyroid Association (ATA) guidelines for the management of medullary thyroid carcinoma (MTC), the A883F mutation has been reclassified from the highest to the high-risk level, although no well-defined risk profile for this mutation exists.

OBJECTIVE

To create a risk profile for the A883F mutation for appropriate classification among the ATA risk levels.

DESIGN

Retrospective analysis.

SETTING

International collaboration.

PATIENTS

Included were 13 A883F carriers.

INTERVENTION

The intervention was thyroidectomy.

MAIN OUTCOME MEASURES

Earliest age of MTC, regional lymph node metastases, distant metastases, age-related penetrance of MTC and pheochromocytoma (PHEO), overall and disease-specific survival, and biochemical cure rate.

RESULTS

One and three carriers were diagnosed at age 7 to 9 years (median, 7.5 years) with a normal thyroid and C-cell hyperplasia, respectively. Nine carriers were diagnosed with MTC at age 10 to 39 years (median, 19 years). The earliest age of MTC, regional lymph node metastasis, and distant metastasis was 10, 20, and 20 years, respectively. Fifty percent penetrance of MTC and PHEO was achieved by age 19 and 34 years, respectively. Five- and 10-year survival rates (both overall and disease specific) were 88% and 88%, respectively. Biochemical cure for MTC at latest follow-up was achieved in 63% (five of eight carriers) with pertinent data.

CONCLUSIONS

MTC of A883F carriers seems to have a more indolent natural course compared with that of M918T carriers. Our results support the classification of the A883F mutation in the ATA high-risk level.