Postoperative Complications After Prophylactic Thyroidectomy for Very Young Patients With Multiple Endocrine Neoplasia Type 2: Retrospective Cohort Analysis

C634Y mutation in RET-induced multiple endocrine neoplasia type 2A: A case report

BACKGROUND

Multiple endocrine neoplasia type 2 (MEN2) is a rare, autosomal dominant endocrine disease. Currently, the RET proto-oncogene is the only gene implicated in MEN2A pathogenesis. Once an RET carrier is detected, family members should be screened to enable early detection of medullary thyroid carcinoma, pheochromocytoma, and hyperparatitity. Among these, medullary thyroid carcinoma is the main factor responsible for patient mortality. Accordingly, delineating strategies to inform clinical follow-up and treatment plans based on genes is paramount for clinical practitioners.

CASE SUMMARY

Herein, we present RET proto-oncogene mutations, clinical characteristics, and treatment strategies in a family with MEN2A. A family study was conducted on patients diagnosed with MEN2A. DNA was extracted from the peripheral blood of family members, and first-generation exon sequencing of the RET proto-oncogene was conducted. The C634Y mutation was identified in three family members spanning three generations. Two patients were sequentially diagnosed with pheochromocytomas and bilateral medullary thyroid carcinomas. A 9-year-old child harboring the gene mutation was diagnosed with medullary thyroid carcinoma. Surgical resection of the tumors was performed. All family members were advised to undergo complete genetic testing related to the C634Y mutation, and the corresponding treatments administered based on test results and associated clinical guidelines.

CONCLUSION

Advancements in MEN2A research are important for familial management, assessment of medullary thyroid cancer invasive risk, and deciding surgical timing.

Impact of Early Diagnostic and Therapeutic Interventions and Clinical Course in Children and Adolescents with Multiple Endocrine Neoplasia Types 1 and 2

PURPOSE

Multiple endocrine neoplasia types 1 (MEN1) and 2 (MEN2) are inherited endocrine tumor syndromes caused by mutations in the MEN1 or RET genes. This study aimed to investigate clinical outcomes and molecular characteristics among children with MEN.

METHODS

This study included eight patients from seven unrelated families. Data on clinical course, biochemical findings, and radiologic studies were collected by retrospective chart review. All diagnoses were genetically confirmed by Sanger sequencing of MEN1 in three MEN1 patients and RET in four patients with MEN2A and one patient with MEN2B.

RESULTS

Three patients with MEN1 from two families presented with hypoglycemia at a mean age of 11±2.6 years. Four patients with MEN2A were genetically diagnosed at a mean of 3.0±2.2 years of age by family screening; one of them was prenatally diagnosed by chorionic villus sampling. Three patients with MEN2A underwent prophylactic thyroidectomy from 5 to 6 years of age, whereas one patient refused surgery. The patient with MEN2B presented with a tongue neuroma and medullary thyroid carcinoma at 6 years of age. Subsequently, he underwent a subtotal colectomy because of bowel perforation and submucosal ganglioneuromatosis at 18 years of age.

CONCLUSION

This study described the relatively long clinical course of pediatric MEN with a mean follow-up duration of 7.5±3.8 years. Insulinoma was the first manifestation in children with MEN1. Early diagnosis by family screening during the asymptomatic period enabled early intervention. The patient with MEN2B exhibited the most aggressive clinical course.

Short-Term Complications After Total Thyroidectomy in Children

INTRODUCTION

Total thyroidectomy for benign disease is becoming more common among children. The purpose of this study was to evaluate 30-day outcomes in children undergoing total thyroidectomy and determine if the short-term outcomes are different in those with a malignant versus benign indication for surgery.

METHODS

This retrospective cohort study used the American College of Surgeons National Surgical Quality Improvement Program-Pediatric (NSQIP-Pediatric) to identify all children who underwent total thyroidectomy from 2015 to 2019. Fisher's exact test was used to compare postoperative outcomes between benign and malignant indications for thyroidectomy.

RESULTS

Among 1595 total thyroidectomy patients, 1091 (68.4%) had a benign indication and 504 (31.6%) had a malignant indication. There were 1234 (77.4%) females, and the median age was 14.9 y (interquartile range [IQR] 12.5, 16.6). Average length of stay (LOS) was similar between cohorts (1.7 d for benign and 1.9 d for malignant, P = 0.30). Parathyroid auto-transplantation was performed in 71 (6.5%) patients in the benign cohort and 43 (8.6%) in the malignant cohort (P = 0.15). The most common complications were readmissions (23 [2.1%] benign and 15 [3.0%] malignant, P = 0.29) and reoperations (7 [0.6%] benign and 5 [1.0%] malignant, P = 0.54). Complication profiles were similar between benign and malignant cohorts (2.8% and 4.6%, respectively [P = 0.10]).

CONCLUSIONS

Children undergoing total thyroidectomy for benign and malignant indications have low rates of 30-d postoperative complications, suggesting that total thyroidectomy is a safe option for children with benign disease. Evaluation of long-term outcomes is needed.

[Hereditary medullary thyroid cancer]

Parafollicular C cells progress via C cell hyperplasia to medullary thyroid cancer (MTC), which can be present even in the first years of life in multiple endocrine neoplasia (MEN) type 2A and 2B patients. Basal calcitonin and carcinoembryonic antigen (CEA) are useful tumor markers for the diagnosis and monitoring. The prognosis depends on the stage when the disease is diagnosed and there is a good genotype-phenotype correlation with the RET proto-oncogene, which can be used for estimation of the risk. The risk-stratified prophylactic thyroidectomy plays a decisive role in the prognosis of known gene mutation carriers.

Risk factors for prolonged hospitalization and readmission after total thyroidectomy in children: Associations with surgical subspecialty

BACKGROUND

Total thyroidectomy (TT) in children is performed by pediatric general surgeons (P-GS), pediatric otolaryngologists (P-ENT), or adult GS/ENT. This study evaluated short-term pediatric TT outcomes, focusing on surgical subspecialties.

METHODS

Pediatric (<18 years) TT with/without central limited lymph node dissection (CLND) between 2015 and 2020 were obtained from the National Surgical Quality Improvement Program-Pediatric database. Risk factors for prolonged hospitalization (PH,>2 days) and 30-day readmission were investigated with multivariate logistic regression.

RESULTS

Of 1535 patients, 14% had PH and 2% were readmitted. PH rates for P-ENT vs. P-GS vs. adult were 21% vs. 11% vs. 10%, respectively. Adjusted risk of PH was higher for P-ENT (OR 1.70, p = 0.003) but similar for P-GS/adult. There was no difference for risk of readmission by subspecialty.

CONCLUSION

PH is more likely after pediatric TT performed by P-ENT, as compared to P-GS or adult surgeons. While TT may be performed safely by individual subspecialties, collaboration across specialties may further optimize outcomes.

Factors associated with postoperative hypocalcemia following thyroidectomy in childhood

BACKGROUND

Postoperative hypocalcemia is a frequent complication after thyroidectomy. Hypoparathyroidism may develop as transient (TtHP), with normalization within six months from surgery, or permanent (PtHP) if the patient requires replacement therapy. We analyzed factors associated with the development of postoperative hypoparathyroidism and in detail PtHP following thyroid surgery in a pediatric population.

PROCEDURE

A retrospective multicenter study analyzing 326 patients was carried out. We recorded gender, age, tumor size, thyroiditis, extrathyroidal extension, lymph node dissection (central/lateral compartment, unilateral/bilateral), parathyroid autotransplantation, and histology. Additionally, calcium levels were acquired postoperatively.

RESULTS

We analyzed pediatric patients ≤18 years who underwent thyroidectomy clustered into age groups (≤15 or > 15). Patients' mean follow-up was 5.8 years (1-11 years). Postoperative hypoparathyroidism occurred in 36 (11.0%): 20 cases (6.13%) developed PtHP. Postoperative hypoparathyroidism was more frequent in younger patients (P = 0.014), in larger tumors (P < 0.001), in case of extrathyroidal extension (P = 0.037), and in central compartment (P = 0.020) and bilateral lymph node dissection (P = 0.030). PtHP was more frequent in older patients (P = 0.014), in case of thyroiditis (P < 0.001), and extrathyroidal extension (P < 0.001). Concerning the first postoperative calcium level measurement, in the postoperative hypoparathyroidism group, we registered a 8.17 mg/dL value with 14% pre/postoperative decrease (Δ_Ca ), whereas in PtHP patient group calcium level was 7.91 mg/dL with 16.7% Δ_Ca .

CONCLUSIONS

The risk of postoperative hypoparathyroidism is related to younger age, tumor size, central compartment and bilateral lymph node dissection, extrathyroidal extension, and decrease in postoperative calcium levels. The risk of PtHP is related to older age, thyroiditis, extrathyroidal extension, and decrease in postoperative calcium levels.

Medullary thyroid carcinoma in children: current state of the art and future perspectives

Medullary thyroid carcinoma (MTC) is a distinct type of malignant thyroid tumor in cell origin, biological behavior, and natural history. It accounts for 1.6% of all thyroid cancers and presents either sporadically or as a hereditary disease, the latter occurring as a part of multiple endocrine neoplasia (MEN) 2A and MEN2B syndromes or as a familial MTC disease with no other manifestations. The gene responsible for the hereditary form is the rearranged during transfection (RET) gene, a proto-oncogene located to human chromosome 10. Most pediatric MTC cases have been discovered after genetic testing investigations, leading to the concept of prophylactic surgery in presymptomatic patients. Therefore, the genetic status of the child, along with serum calcitonin levels and ultrasonographic findings, determine the appropriate age for prophylactic surgical intervention. Nevertheless, a diagnosis at an early stage of MTC warrants total thyroidectomy and central lymph node dissection with the addition of lateral/contralateral lymph node dissection depending on the tumor size, ultrasonographic evidence of neck disease, or calcitonin levels. Conversely, locally advanced/unresectable or metastatic MTC is primarily treated with multikinase inhibitors, while more specific RET inhibitors are being tested in clinical trials with promising results.

Active Surveillance in RET Gene Carriers Belonging to Families with Multiple Endocrine Neoplasia

Simple Summary

MEN2 has a very high penetrance for the development of medullary thyroid cancer. However, intra- and inter-familial variabilities have been described. Accordingly, in this precision medicine era, a personalized approach should be adopted in subjects harboring RET mutations. In these subjects, we showed that thyroid surgery could be safely timed according to basal and stimulated calcitonin, especially in children who can reach adulthood, avoiding the risks of thyroid surgery and decreasing the period of a long-life hypothyroidism treatment.

Abstract

Multiple Endocrine Neoplasia 2 (MEN2) is a hereditary cancer syndrome for developing medullary thyroid cancer (MTC) due to germline mutations of RET gene. Subjects harboring a germline RET mutation without any clinical signs of MTC are defined as gene carriers (GCs), for whom guidelines propose a prophylactic thyroid surgery. We evaluate if active surveillance of GCs, pursuing early thyroid surgery, can be safely proposed and if it allows safely delaying thyroid surgery in children until adolescence/adulthood. We prospectively followed 189 GCs with moderate or high risk germline RET mutation. Surgery was planned in case of: elevated basal calcitonin (bCT) and/or stimulated CT (sCT); surgery preference of subjects (or parents, if subject less than 18 years old); other reasons for thyroid surgery. Accordingly, at RET screening, we sub-grouped GCs in subjects who promptly were submitted to thyroid surgery (Group A, n = 67) and who were not (Group B, n = 122). Group B was further sub-grouped in subjects who were submitted to surgery during their active surveillance (Group B1, n = 22) and who are still in follow-up (Group B2, n = 100). Group A subjects presented significantly more advanced age, bCT and sCT compared to Group B. Mutation RET^V804M was the most common variant in both groups but it was significantly less frequent in Group A than B. Analyzing age, bCT, sCT and genetic landscape, Group B1 subjects differed from Group B2 only for sCT at last evaluation. Group A subjects presented more frequently MTC foci than Group B1. Moreover, Group A MTCs presented more aggressive features (size, T and N) than Group B1. Accordingly, at the end of follow-up, all Group B1 subjects presented clinical remission, while 6 and 12 Group A MTC patients had structural and biochemical persistent disease, respectively. Thank to active surveillance, only 13/63 subjects younger than 18 years at RET screening have been operated on during childhood and/or adolescence. In Group B1, three patients, while actively surveilled, had the possibility to reach the age of 18 (or older) and two patients the age of 15, before being submitted to thyroid surgery. In Group B2, 12 patients become older than 18 years and 17 older than 15 years. In conclusion, we demonstrated that an active surveillance pursuing an early thyroid surgery could be safely recommended in GCs. This patient-centered approach permits postponing thyroid surgery in children until their adolescence/adulthood. At the same time, we confirmed that genetic screening allows finding hidden MTC cases that otherwise would be diagnosed much later.

Multiple endocrine neoplasia type 2: A reveiw

Multiple endocrine neoplasias are rare hereditary syndromes some of them with malignant potential. Multiple endocrine neoplasia type 2 (MEN 2) is an autosomal dominant hereditary cancer syndrome due to germline variants in the REarranged during Transfection (RET) proto-oncogene. There are two distinct clinical entities: MEN 2A and MEN 2B. MEN 2A is associated with medullary thyroid carcinoma (MTC), phaeochromocytoma, primary hyperparathyroidism, cutaneous lichen amyloidosis and Hirschprung's disease and MEN 2B with MTC, phaeochromocytoma, ganglioneuromatosis of the aerodigestive tract, musculoskeletal and ophthalmologic abnormalities. Germline RET variants causing MEN 2 result in gain-of-function; since the discovery of the genetic variants a thorough search for genotype-phenotype associations began in order to understand the high variability both between families and within family members. These studies have successfully led to improved risk classification of prognosis in relation to the genotype, thus improving the management of the patients by thorough genetic counseling. The present review summarizes the recent developments in the knowledge of these hereditary syndromes as well as the impact on clinical management, including genetic counseling, of both individual patients and families. It furthermore points to future directions of research for better clarification of timing of treatments of the various manifestations of the syndromes in order to improve survival and morbidity in these patients.

The revised clinical practice guidelines on the management of thyroid tumors by the Japan Associations of Endocrine Surgeons: Core questions and recommendations for treatments of thyroid cancer

The Japan Associations of Endocrine Surgeons has developed the revised version of the Clinical Practice Guidelines for Thyroid Tumors. This article describes the guidelines translated into English for the 35 clinical questions relevant to the therapeutic management of thyroid cancers. The objective of the guidelines is to improve health-related outcomes in patients with thyroid tumors by enabling users to make their practice evidence-based and by minimizing any variations in clinical practice due to gaps in evidential knowledge among physicians. The guidelines give representative flow-charts on the management of papillary, follicular, medullary, and anaplastic thyroid carcinoma, along with recommendations for clinical questions by presenting evidence on the relevant outcomes including benefits, risks, and health conditions from patients' perspective. Therapeutic actions were recommended or not recommended either strongly (◎◎◎ or XXX) based on good evidence (😊)/good expert consensus (+++), or weakly (◎, ◎◎ or X, XX) based on poor evidence (😣)/poor expert consensus (+ or ++). Only 10 of the 51 recommendations given in the guidelines were supported by good evidence, whereas 35 were supported by good expert consensus. While implementing the current guidelines would be of help to achieve the objective, we need further clinical research to make our shared decision making to be more evidence-based.

Thyroid surgery in 103 children in a single institution from 2000-2014

BACKGROUND

Data on thyroid surgery in children are scarce.

OBJECTIVE

Analyze outcome data on thyroid surgery in a pediatric population.

DESIGN

Medical record review.

SETTING

Tertiary health care institution.

PATIENTS AND METHODS

We collected demographic and clinical data on patients 18 years or younger who had thyroid surgery in the period 2000 to 2014. Descriptive data are presented.

MAIN OUTCOME MEASURES

Indications for thyroidectomy, thyroid pathology, complications, length of stay, and radioactive iodine treatment and recurrences.

SAMPLE SIZE

103.

RESULTS

Of 103 patients who underwent 112 thyroidectomy procedures, 80 (78%) were females and the mean age at operation was 13.2 years. and 17 (16%) were associated with multiple endocrine neoplasia type 2. There was no history of radiation exposure. Eighty-one patients (78%) had fine needle aspiration (FNA) which correlated with the final histopathology in 94% of cases. Sixty-six patients (64%) had malignant cancer (61 papillary), 44 (74.6%) of 59 patients who had neck dissection had lymph node metastasis and 7 (11%) had distant metastases to the lung. Procedures included total thyroidectomy (50%), hemithyroidectomy (17%), completion (31%), and subtotal thyroidectomy (2%). Twenty-three patients (22%) developed hypocalcemia (3 permanent) and 6 (5.8%) had unilateral recurrent laryngeal nerve injury (3 permanent). Patients were followed up for a mean duration of 71.7 months (median 60 months). Of 66 patients with thyroid cancer, 43 (65%) received radioactive iodine, and 10 (15%) had recurrence.

CONCLUSION

Malignancy is the commonest indication for thyroid surgery in children and FNA is highly diagnostic. Hypocalcemia and recurrent laryngeal nerve injury are significant complications. The recurrence rate in thyroid cancer is 15%.

LIMITATIONS

Retrospective.

CONFLICT OF INTEREST

None.

Practice Patterns and Outcomes of Pediatric Thyroid Surgery: An NSQIP Analysis

BACKGROUND

Pediatric thyroid cancer rates are rising. The aim of this study was to determine the state of current practice and outcomes for pediatric thyroidectomies using the pediatric National Surgical Quality Improvement Program (NSQIP-P) with specific attention to differences based on surgeon type/specialty.

METHODS

All cases of pediatric thyroidectomies and neck dissections within the NSQIP-P database were identified from 2015 to 2017. Patient, disease, and treatment-related factors affecting 30-day outcomes were analyzed using univariate and multivariate analyses.

RESULTS

A total of 1300 cases were identified. Mean age at time of surgery was 14.0 (SD 3.5) years. The majority of patients were female (78%) and Caucasian (72%). Pediatric general surgeons performed the largest proportion of cases (42%) followed by pediatric otolaryngologists (33%). Malignancies were present in 29% of cases. The overall rate of complications was 3.0%. On multivariate analysis, non-pediatric surgeons were more likely to operate on Caucasian children, malignant pathology, and perform modified radical neck dissections. Pediatric surgeons were more likely to have longer operative times, have specialized in otolaryngology, and operate on sicker children (ASA>2). There were no differences in length of stay or overall complications rates.

CONCLUSIONS

This study shows that pediatric surgeons currently perform the majority of thyroid surgeries in children. While unable to assess surgeon volume, our data show that thyroid surgery is being safely performed at NSQIP-affiliated hospitals by both non-pediatric and pediatric surgeons. Further studies are needed to determine if there are differences in specific procedure-related complications and long-term outcomes between surgeon types.

Outpatient thyroidectomy in the pediatric population

Preoperative optimization and patient education have allowed for the transition of thyroid surgery to the outpatient setting over the last few decades. Performing these operations in the outpatient setting has proven to be cost-effective and safe in the adult population. The purpose of this study is to evaluate the safety and efficacy of outpatient thyroid surgery in the pediatric population. A retrospective review from December 2015 to February 2019 of patients under the age of 18 years of age undergoing thyroidectomy performed by two endocrine surgeons at a large academic was performed. There were 55 consecutive operations performed in 51 patients for thyroid pathology, two were excluded as they were inpatient procedures. Cases were reviewed for complications, unplanned same-day admission, 30-day admission, unplanned reoperation, and death. Mean age was 15 ± 0.3 years (range 9-18 years), 79% of the patients were female. Operations were performed for Graves' disease (n = 29), thyroid cancer (n = 9), thyroid nodule (n = 6), multinodular goiter (n = 4), Hashimoto's disease (n = 3), and toxic adenoma (n = 2). Operations performed included: total thyroidectomy (n = 36), thyroid lobectomy (n = 13), total thyroidectomy with lymph node dissection (n = 2), and lateral neck dissection (n = 2). All patients were discharged home within 6 h after completion of the operation. Five (9.4%) patients had transient hypoparathyroidism, with parathyroid hormone levels <10 pg/mL immediately postoperatively. One patient (1.9%) developed a postoperative hematoma on postoperative day six and required reoperation and readmission. Two patients (3.8%) had permanent hypoparathyroidism and one had transient hoarseness (1.9%). There were otherwise no readmissions or ED visits. In conclusion, outpatient thyroid surgery is safe and effective for pediatric patients.

Risks of Hypoparathyroidism After Total Thyroidectomy in Children: A 21-Year Experience in a High-Volume Cancer Center

BACKGROUND

Hypoparathyroidism occurs relatively frequently after thyroid surgery in children. However, few studies have reported risk factors. We aimed to identify risk factors for hypoparathyroidism that occurred after total thyroidectomy for proven or suspected malignancy in children.

METHODS

Children (aged ≤ 18 years) who underwent total thyroidectomy for neoplasm or RET germline mutation at our institution between 1997 and 2018 were included. We retrospectively reviewed demographics, surgical indications, perioperative and follow-up laboratory results, pathologic results, and duration of calcium/calcitriol supplementation. Risk factors for hypoparathyroidism were identified by multivariate analysis.

RESULTS

Of 184 consecutive patients, 111 had undergone surgery for neoplasm; these diseases were primarily malignancies (106, 95.5%), predominantly papillary carcinoma (103, 92.8%). The remaining 73 patients had undergone early thyroidectomy for RET germline mutation. Among all patients, 67 (36.4%) had hypoparathyroidism: 61 transient and 6 permanent. In a multivariate analysis, central neck dissection (odds ratio 4.3, 95% confidence interval 2.0-9.1) and gross extrathyroidal extension (odds ratio 4.9, 95% confidence interval 2.0-12.1) predicted overall hypoparathyroidism; however, no significant factors were associated with permanent hypoparathyroidism. Most patients with permanent hypoparathyroidism (5 of 6) had undergone therapeutic central neck dissection. When central neck dissection was performed, younger children had a higher risk of overall hypoparathyroidism.

CONCLUSIONS

In pediatric total thyroidectomies, central neck dissection and gross extrathyroidal extension were major predictors for overall hypoparathyroidism. Surgeons performing thyroidectomy in such patients should be aware of the relatively high risk, preserve parathyroid tissue to the extent possible, and be conscientious regarding postoperative calcium monitoring and replacement.

5P Strategies for Management of Multiple Endocrine Neoplasia Type 2: A Paradigm of Precision Medicine

Multiple endocrine neoplasia type 2 (MEN2) is a neuroendocrine cancer syndrome characterized by medullary thyroid carcinoma, in combination or not with pheochromocytoma, hyperparathyroidism, and extra-endocrine features. MEN2 syndrome includes two clinically distinct forms subtyped as MEN2A and MEN2B. Nearly all MEN2 cases are caused by germline mutations of the RET proto-oncogene. In this review, we propose "5P" strategies for management of MEN2: prevention, prediction, personalization, psychological support, and participation, which could effectively improve clinical outcomes of patients. Based on RET mutations, MEN2 could be prevented through prenatal diagnosis or preimplantation genetic testing. Identification of pathogenic mutations in RET can enable early diagnosis of MEN2. Combining RET mutation testing with measurement of serum calcitonin, plasma or urinary metanephrine/normetanephrine, and serum parathyroid hormone levels could allow risk stratification and accurately prediction of MEN2 progression, thus facilitating implementation of personalized precision treatments to increase disease-free survival and overall survival. Furthermore, increased awareness of MEN2 is needed, which requires participation of physicians, patients, family members, and related organizations. Psychological support is also important for patients with MEN2 to promote comprehensive management of MEN2 symptoms. The "5P" strategies for management of MEN2 represent a typical clinical example of precision medicine. These strategies could effectively improve the health of MEN2 patient, and avoid adverse outcomes, including death and major morbidity, from MEN2.

Preimplantation Genetic Testing of Multiple Endocrine Neoplasia Type 2A

Background: When discussing matters of reproduction, the 2015 revised guidelines for the management of medullary thyroid carcinoma recommend that patients diagnosed with multiple endocrine neoplasia type 2A (MEN 2A) are informed about the option of Preimplantation Genetic Testing for Monogenic Disorders (PGT-M). In addition, patients seem to have a genuine interest in reproductive options. However, there are just two reports worldwide of this technology being used for patients with MEN 2A. We here present, in a Danish couple where the man has MEN 2A, the first European family with children born after PGT-M. Objective: To report the results of PGT-M in relation to multiple endocrine neoplasia type 2A with the aim to increase awareness among physicians treating this and other genetic disorders. Methods: A Danish couple was referred to the PGT Center at Copenhagen University Hospital Rigshospitalet and opted for PGT-M after counseling by a clinical geneticist and a fertility doctor. The embryos were diagnosed using microsatellite polymorphic marker close to RET. Results: The couple had two healthy children born in 2017 and 2019 as a result of a total of three ICSI treatments including controlled ovarian stimulation, oocyte retrieval and PGT-M, and a total of six blastocyst transfers. Conclusion: A session with a clinical geneticist covering all reproductive options for patients in early adult life is a relevant part of the clinical management of patients with MEN 2A, and other patients with hereditary cancer predisposition syndromes.

Long-term outcome after DNA-based prophylactic neck surgery in children at risk of hereditary medullary thyroid cancer

Advances in sequencing technology, providing unprecedented insights into cancer progression, have shifted the treatment paradigm towards precision medicine for hereditary medullary thyroid cancer (MTC), away from the 'one-size-fits-all' approach predicated on genetic risk alone. The DNA-based/biochemical concept, factoring serum calcitonin into the benefit-risk equation, optimizes biochemical cure while minimizing extent of prophylactic surgery and operative morbidity in children at risk. The transformative effect that has taking effect on medical practice has been impressive: Increasingly earlier molecular diagnosis and more limited prophylactic neck operations yielded excellent clinical outcomes at expert facilities 7-16 years postoperatively: biochemical cure rates approximating 100%; absence of residual structural disease or recurrence; and rarely any permanent operative morbidity. These excellent results, contingent on proper health care funding and pediatric surgical specialization, make a case for early prophylactic thyroidectomy in experienced hands once calcitonin serum levels exceed the upper normal limit of the assay in young gene carriers.

Present status of prophylactic thyroidectomy in pediatric multiple endocrine neoplasia 2: a nationwide survey in Japan 1997-2017

Background In Japan, prophylactic thyroidectomy involves out-of-pocket expense. The American Thyroid Association (ATA) recommends prophylactic thyroidectomy for medullary thyroid carcinoma (MTC) during early childhood in patients with multiple endocrine neoplasia type 2 (MEN2). The ATA reports a high frequency of postoperative complications in childhood, which also influenced the delay of prophylactic thyroidectomy in Japan. Methods This retrospective study of multiple medical centers in Japan included individuals aged <20 years diagnosed with germline RET mutations between 1997 and 2017. The onset and onset possibility were defined based on confirmed lesions or calcitonin levels. The definition of risk and prophylactic thyroidectomy were based on the ATA 2015 revised guideline. Results Twenty-one patients with MEN2 were enrolled (highest risk, n = 5; high risk, n = 5; and moderate risk, n = 11). The cumulative incidence of the onset/onset possibility reached 50% at 5 and 8 years and 100% at 9 years and 17 years in high- and moderate-risk patients, respectively. Of 7 patients with MEN2A, 71% underwent prophylactic thyroidectomy. Only one 5-year-old patient (C634Y) had increased serum calcitonin level after prophylactic thyroidectomy in the MEN2A group. The only permanent complication, which did not occur in patients who underwent total thyroidectomy alone, was hypoparathyroidism (33% of patients). This permanent complication occurred with clinically developed MTC. No permanent postoperative complications occurred in patients aged 5-6 years. Conclusions Prophylactic thyroidectomy reduces recurrence and postoperative complications in pediatric patients with MEN2. Early thyroidectomy based on only calcitonin level could possibly reduce thyroidectomy delay.

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.

A comprehensive review on MEN2B

MEN2B is a very rare autosomal dominant hereditary tumor syndrome associated with medullary thyroid carcinoma (MTC) in 100% cases, pheochromocytoma in 50% cases and multiple extra-endocrine features, many of which can be quite disabling. Only few data are available in the literature. The aim of this review is to try to give further insights into the natural history of the disease and to point out the missing evidence that would help clinicians optimize the management of such patients. MEN2B is mainly characterized by the early occurrence of MTC, which led the American Thyroid Association to recommend preventive thyroidectomy before the age of 1 year. However, as the majority of mutations are de novo, improved knowledge of the nonendocrine signs would help to lower the age of diagnosis and improve long-term outcomes. Future large-scale studies will be aimed at characterizing more in detail the main characteristics and outcomes of MEN2B.

Advances in risk-oriented surgery for multiple endocrine neoplasia type 2

Genetic association studies hinge on definite clinical case definitions of the disease of interest. This is why more penetrant mutations were overrepresented in early multiple endocrine neoplasia type 2 (MEN2) studies, whereas less penetrant mutations went underrepresented. Enrichment of genetic association studies with advanced disease may produce a flawed understanding of disease evolution, precipitating far-reaching surgical strategies like bilateral total adrenalectomy and 4-gland parathyroidectomy in MEN2. The insight into the natural course of the disease gleaned over the past 25 years caused a paradigm shift in MEN2: from the removal of target organs at the expense of greater operative morbidity to close biochemical surveillance and targeted resection of adrenal tumors and hyperplastic parathyroid glands. The lead time provided by early identification of asymptomatic MEN2 carriers under biochemical surveillance delimits a 'window of opportunity', within which (i) pre-emptive total thyroidectomy alone is adequate, circumventing morbidity attendant to central node dissection; (ii) subtotal 'tissue-sparing' adrenalectomy is sufficient, trading the risk of steroid dependency for the risk of a second pheochromocytoma in the adrenal remnant and (iii) parathyroidectomy is limited to enlarged glands, trading the risk of postoperative hypoparathyroidism for the risk of leaving behind hyperactive parathyroid glands. Future research should delineate further the mutation-specific, age-dependent penetrance of pheochromocytoma and primary hyperparathyroidism to refine the risk-oriented approach to MEN2. The sweeping changes in the management of MEN2 since the new millenium hold the hope that death and major morbidity from this uncommon disease can be eliminated in our lifetime.

Long-term outcome of prophylactic thyroidectomy in children carrying RET germline mutations

Background

A comprehensive assessment has not been undertaken of long-term outcomes in children carrying germline RET mutations and undergoing prophylactic thyroidectomy with the aim of preventing medullary thyroid cancer (MTC).

Methods

A retrospective outcome study (1994–2017) of prophylactic thyroidectomy in children, with and without central node dissection, was performed at a tertiary surgical centre.

Results

Some 167 children underwent prophylactic thyroidectomy, 109 without and 58 with concomitant central node dissection. In the highest-risk mutational category, MTC was found in five of six children (83 per cent) aged 3 years or less. In the high-risk category, MTC was present in six of 20 children (30 per cent) aged 3 years or less, 16 of 36 (44 per cent) aged 4–6 years, and 11 of 16 (69 per cent) aged 7–12 years (P = 0·081). In the moderate-risk category, MTC was seen in one of nine children (11 per cent) aged 3 years or less, one of 26 (4 per cent) aged 4–6 years, three of 26 (12 per cent) aged 7–12 years, and seven of 16 (44 per cent) aged 13–18 years (P = 0·006). Postoperative hypoparathyroidism was more frequent in older children (32 per cent in the oldest age group versus 3 per cent in the youngest; P = 0·002), whether or not central node dissection was carried out. Three children developed recurrent laryngeal nerve palsy; all had undergone central node dissection (P = 0·040). All complications resolved within 6 months. Postoperative normalization of calcitonin serum levels was achieved in 114 (99·1 per cent) of 115 children with raised preoperative values. No residual structural disease or recurrence was observed.

Conclusion

Early prophylactic thyroidectomy is a viable surgical concept in experienced hands, sparing older children the postoperative morbidity associated with delayed neck surgery.

Outcome of Treatment for Medullary Thyroid Carcinoma-a Single Centre Experience

We conducted this study to evaluate the demography, clinical presentation, management and outcomes of medullary thyroid carcinoma (MTC) from the Indian context. This was a retrospective study of patients with MTC managed between January 2008 and December 2016. All pertinent data was collected and the results were analysed using STATA (v.13.1). MTC accounted for 90/2022 (4.45%) patients managed with thyroid cancer during the study period. The mean age of presentation was 40 years (range 14-70 years) with 47 males and 43 females. The most common presentation included goitre with cervical lymphadenopathy seen in 60 patients (66.7%). There were 11 patients (12.2%) with systemic metastasis at presentation. Rearranged during transfection (RET) testing was performed in 71 patients and was positive in 25 (35.2%). The mutations among these patients were seen in the following codons: 634 (12), 804 (8), 790 (3) and 618 (2). Persistent hypercalcitoninemia (calcitonin > 50 pg/ml) was observed in 62/80 (77.5%) patients. Forty patients underwent a meta-iodo-benzyl-guanidine (MIBG) scan in the postoperative period, 10 were positive. The mean duration of follow-up was 32 months and 10 patients defaulted from follow-up. Sixteen patients developed metastasis during the period of follow-up while eight patients expired. The mean survival was 85.75 months (95% CI 78.7-92.7). MTC accounted for 4.5% of thyroid carcinomas in this cohort among which 35% were hereditary. Persistent hypercalcitoninemia following surgery is seen in more than 70% of patients but this does not affect survival. RET screening should be performed for all patients with MTC as curative surgery can be offered for mutation positive offspring.

Detection of early stage medullary thyroid carcinoma by measuring serum calcitonin using an electro chemiluminescence immuno-assay: A case report of a young Japanese woman with a high-risk RET mutation

Medullary thyroid carcinoma (MTC) in multiple endocrine neoplasia type 2 (MEN2) is an autosomal dominant disorder caused by the mutation of the RET proto-oncogene, that shows nearly complete penetration. The American Thyroid Association guidelines recommend prophylactic thyroidectomy for patients with high-risk RET mutations. However, in Japan, ethical and medical issues may preclude prophylactic treatment in young patients. Hence, an early diagnosis of MTC is necessary to ensure a favorable outcome. Here, we report the case of a young Japanese girl with a high-risk RET mutation, diagnosed with very early stage MTC using serum calcitonin (Ctn) values measured using an electro chemiluminescence immuno-assay (ECLIA). The Japanese girl with a family history of MEN2 had been followed at our hospital since she was 5-mo-old. RET analysis revealed that she displayed a Cys634Gly mutation. The patient underwent annual neck ultrasonography and calcium infusion testing. When she was 8-yr-old, the Ctn level, measured using ECLIA, dramatically increased with calcium stimulation, from a baseline of 11.3 pg/mL to 333 pg/mL. She subsequently underwent total thyroidectomy and was diagnosed with stage I MTC. Detecting early stage MTC by monitoring serum Ctn measured by ECLIA, may represent a useful strategy for patients with high-risk RET mutations.

Perioperative determinants of transient hypocalcemia after pediatric total thyroidectomy

PURPOSE

We seek to identify risk factors associated with hypocalcemia after pediatric total thyroidectomy.

METHODS

We retrospectively reviewed patients younger than 21years undergoing total thyroidectomy between January 2002 and January 2016. We defined hypocalcemia as any serum calcium <8mg/dl or ionized calcium <1.0mmol/L. Perioperative risk factors were identified through multivariate logistic regression.

RESULTS

Ninety-one children underwent total thyroidectomy. The average age was 13.7±4.4years, and 77% were female. Transient hypocalcemia was diagnosed in 34% (n=31) of patients. There was one case of permanent hypoparathyroidism. Predictors of transient hypocalcemia included age (OR 0.87, 95% CI 0.8-0.97, p=0.01), lymphadenectomy (OR 6.6, 95% CI 1.7-31.6, p=0.01), and hyperthyroidism (OR 13.3, 95% CI 1.3-1849, p=0.03). Patients with malignancy undergoing central (OR 7.1, 95% CI 1.5-33.4, p=0.01) or central plus lateral lymphadenectomy (OR 6.33, 95% CI 1.0-40.1, p=0.05) had significantly increased risk for transient hypocalcemia. Malignancy, MEN2A/B, goiter, preoperative calcium supplementation, incidental parathyroid removal, and postoperative PTH <15pg/ml were not associated with transient hypocalcemia.

CONCLUSIONS

Younger age, hyperthyroidism, and concomitant lymphadenectomy during total thyroidectomy increase risk of developing transient hypocalcemia. Malignant cases with central or central plus lateral lymphadenectomy are also at increased risk. Aggressive perioperative management of hypocalcemia should be initiated in patients with these risk factors.

LEVEL OF EVIDENCE

2b.

Oncogenesis of Thyroid Cancer

Thyroid neoplasms encompass a variety of lesions that range from benign adenomas to malignancies. These latter can be well-differentiated, poorly differentiated or undifferentiated (anaplastic) carcinomas. More than 95% of thyroid cancers are derived from thyroid follicular cells, while 2-3% (medullary thyroid cancers, MTC) originate from calcitonin producing C-cells. Over the last decade, investigators have developed a clearer understanding of genetic alterations underlying thyroid carcinogenesis. A number of point mutations and translocations are involved, not only in its tumorigenesis, but also as have potential use as diagnostic and prognostic indicators and therapeutic targets. Many occur in genes for several important signaling pathways, in particular the mitogen-activated protein kinase (MAPK) pathway. Sporadic (isolated) lesions account for 75% of MTC cases, while inherited MTC, often in association with multiple endocrine neoplasia (MEN) type 2A and 2B syndromes, constitute the remainder. However, non-MEN familial MTC may also occur. Advances in genetic testing have revolutionized the management of MTC, with prospects of genetic screening, testing and early prophylactic thyroidectomy. Ethical concerns of these advances are addressed.

Impact of central node dissection on postoperative morbidity in pediatric patients with suspected or proven thyroid cancer

BACKGROUND

Pediatric risk factors for postoperative morbidity after central node dissection are ill-defined.

METHODS

This outcome study aimed to evaluate operative morbidity in patients aged ≤18 years after total thyroidectomy with or without central node dissection for suspected or proven thyroid cancer.

RESULTS

Included were 102 patients with hereditary C-cell hyperplasia, 66 patients with medullary, 60 patients with papillary, and 2 patients with follicular thyroid cancer. In all 230 patients, 131 of whom underwent central node dissection, transient recurrent laryngeal nerve palsy was significantly associated only with central node dissection (100% vs 55%; P = .010). Transient and permanent hypoparathyroidism were significantly associated with age (means of 11.9 years versus 7.8 years, and 12.9 years versus 8.5 years; P ≤ .002); central node dissection (80% vs 50%, and 100% vs 54%; P ≤ .001); and the number of central lymph nodes cleared (means of 12.2 nodes versus 5.4 nodes, and 26.9 nodes versus 5.8 nodes, P < .001). These effects were stronger for permanent than transient hypoparathyroidism. Correlations between permanent hypoparathyroidism and the number of nodes cleared on central node dissection (r = 0.35) were closer than those between permanent hypoparathyroidism and age (r = 0.15), but similar for transient hypoparathyroidism (r = 0.22 and r = 0.25).

CONCLUSION

Owing to the incremental morbidity from central node dissection, the extent of a neck operation, in experienced hands, should be tailored to the extent of the underlying disease regardless of the child's age. The notion that the experience of the center and surgeons may be more important than the age of the child requires validation in independent series across different health care settings.