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.</p

Risk profile of the RET A883F germline mutation: an international collaborative study

Context: The A883F germline mutation of the REarranged during Transfection 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 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 in 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 7-9 years (median 7.5) with a normal thyroid and C-cell hyperplasia, respectively. Nine carriers had MTC diagnosed at age 10-39 years (median 19). The earliest age of MTC, regional lymph node and distant metastasis were 10, 20, 20 years, respectively. Fifty percent penetrance of MTC and PHEO was achieved by age 19 and 34 years, respectively. Five- and 10-year survival (both overall and disease-specific) were 88% and 88%, respectively. Biochemical cure for MTC at latest follow-up was achieved in 63% (5/8 carriers) with pertinent data. Conclusions: MTC of A883F carriers seems to have a more indolent natural course compared to that of M918T carriers. Our results support the classification of the A883F mutation in the ATA high risk level

Variability in Medullary Thyroid Carcinoma in RET L790F Carriers:A Case Comparison Study of Index Patients

Background: Previous studies have suggested that the variability in age of onset and aggressiveness of medullary thyroid carcinoma (MTC) in patients with multiple endocrine neoplasia type 2A (MEN 2A) carrying the same REarranged during Transfection (RET) mutation may be caused by additional RET germline variants or somatic variants. Methods: This study was a retrospective case comparison study of all MEN 2A index patients (n = 2) with the RET L790F germline mutation in Denmark. Whole blood and MTC tissue were analyzed for RET germline variants and other somatic variants (&gt;500), respectively. Results: Patient 1 presented with MTC (T1aN1bM0) at age 14 years, while patient 2 presented with MTC (T1bN0M0) at age 70 years. No germline RET germline variants nor other variants were found to explain this MTC variability. Conclusions: We could not confirm the previously reported finding of a somatic RET variant as likely responsible for the early onset and aggressiveness of MTC in a RET germline mutation carrier. Also, we found no RET germline variants that could explain the MTC variability among our index patients. We did, however, identify a somatic FLT3 R387Q variant with an unknown potential as genetic modifier. Further large-scale studies are needed to investigate genetic modifiers in RET L790F carriers.</p

Distribution of <i>RET</i> Mutations in Multiple Endocrine Neoplasia 2 in Denmark 1994-2014:A Nationwide Study

Background: Germline mutations of the REarranged during Transfection (RET) proto-oncogene cause multiple endocrine neoplasia 2 (MEN2). It is unclear whether the distribution of RET mutations varies among populations. The first nationwide study of the distribution of RET mutations was conducted, and the results were compared to those of other populations. Methods: This retrospective cohort study included 1583 patients who underwent RET gene testing in one of three centers covering all of Denmark between September 1994 and December 2014. Primary testing method was Sanger sequencing, which included exons 8–11 and 13–16. Mutations were defined according to the ARUP database July 1, 2016. Results: RET mutations were identified in 163 patients from 36 apparently unrelated families. Among the 36 families 13 (36.1%) carried mutations in codon 611, four (11.1%) in codon 618, three (8.3%) in codon 620, one (2.8%) in codon 631, six (16.7%) in codon 634, one (2.8%) in codon 790, one (2.8%) in codon 804, one (2.8%) in codon 852, one (2.8%) in codon 883, and five (13.9%) in codon 918. Among the 13 families with codon 611 mutations, 12 had the p.C611Y mutation. Conclusions: The distribution of RET mutations in Denmark appears to differ from that of other populations. Mutations in codon 611 were the most prevalent, followed by more frequently reported mutations. This might be due to a possible founder effect for the p.C611Y mutation. However, further studies are needed to find possible explanations for the skewed mutational spectrum in Denmark

Replication of newly proposed TNM staging system for medullary thyroid carcinoma:a nationwide study

A recent study proposed new TNM groupings for better survival discrimination among stage groups for medullary thyroid carcinoma (MTC) and validated these groupings in a population-based cohort in the United States. However, it is unknown how well the groupings perform in populations outside the United States. Consequently, we conducted the first population-based study aiming to evaluate if the recently proposed TNM groupings provide better survival discrimination than the current American Joint Committee on Cancer (AJCC) TNM staging system (seventh and eighth edition) in a nationwide MTC cohort outside the United States. This retrospective cohort study included 191 patients identified from the nationwide Danish MTC cohort between 1997 and 2014. In multivariate analysis, hazard ratios for overall survival under the current AJCC TNM staging system vs the proposed TNM groupings with stage I as reference were 1.32 (95% CI: 0.38–4.57) vs 3.04 (95% CI: 1.38–6.67) for stage II, 2.06 (95% CI: 0.45–9.39) vs 3.59 (95% CI: 1.61–8.03) for stage III and 5.87 (95% CI: 2.02–17.01) vs 59.26 (20.53–171.02) for stage IV. The newly proposed TNM groupings appear to provide better survival discrimination in the nationwide Danish MTC cohort than the current AJCC TNM staging. Adaption of the proposed TNM groupings by the current AJCC TNM staging system may potentially improve accurateness in survival discrimination. However, before such an adaption further population-based studies securing external validity are needed

Incidence and prevalence of multiple endocrine neoplasia 2a in denmark 1901–2014:A nationwide study

Background: The incidence and prevalence of multiple endocrine neoplasia 2A (MEN2A) have only been reported once in a nationwide setting. However, it is unclear whether the figures are representative of other populations, as the major component of the syndrome, hereditary medullary thyroid carcinoma (MTC), has been reported as rare in the same country. We conducted a nationwide retrospective cohort study of MEN2A in Denmark from 1901 to 2014, aiming to describe the incidence and prevalence.Methods: This study included 250 unique MEN2A patients born or resident in Denmark before December 31, 2014. Patients were identified through the Danish REarranged during Transfection (RET) cohort, linkage of MEN2A pedigrees, the Danish MTC cohort, a nationwide collaboration of MEN2 centers, cross-checking of other relevant cohorts, and a systematic literature search.Results: The incidence from 1971 to 2000 was 28 (95% CI: 21-37) per million live births per year. Incidence for the specific mutations or for the overall MEN2A group did not change significantly from 1901 to 2014 (P&gt;0.05). Point prevalence at January 1, 2015, was 24 per million (95% CI: 20-28).Conclusion: The incidence and prevalence of MEN2A in Denmark seem higher than those reported in other countries. This is likely explained by the Danish C611Y founder effect. Also, our data indicate no significant change in MEN2A incidence during the last century.</p

Completeness of RET testing in patients with medullary thyroid carcinoma in Denmark 1997-2013:a nationwide study

Background: The completeness of REarranged during Transfection (RET) testing in patients with medullary thyroid carcinoma (MTC) was recently reported as 60%. However, the completeness on a population level is unknown. Similarly, it is unknown if the first Danish guidelines from 2002, recommending RET testing in all MTC patients, improved completeness in Denmark. We conducted a nationwide retrospective cohort study aiming to evaluate the completeness of RET testing in the Danish MTC cohort. Additionally, we aimed to assess the completeness before and after publication of the first Danish guidelines and characterize MTC patients who had not been tested.Methods: The study included 200 patients identified from the nationwide Danish MTC cohort 1997-2013. To identify RET tested MTC patients before December 31, 2014, the MTC cohort was cross-checked with the nationwide Danish RET cohort 1994-2014. To characterize MTC patients who had not been RET tested, we reviewed their medical records and compared them with MTC patients who had been tested.Results: Completeness of RET testing in the overall MTC cohort was 87% (95% CI: 0.81-0.91; 173/200). In the adjusted MTC cohort, after excluding patients diagnosed with hereditary MTC by screening, completeness was 83% (95% CI: 0.76-0.88; 131/158). Completeness was 88% (95% CI: 0.75-0.95; 42/48) and 81% (95% CI: 0.72-0.88) (89/110) before and after publication of the first Danish guidelines, respectively. Patients not RET tested had a higher median age at diagnosis compared to those RET tested. Median time to death was shorter in those not tested relative to those tested.Conclusion: The completeness of RET testing in MTC patients in Denmark seems to be higher than reported in other cohorts. No improvement in completeness was detected after publication of the first Danish guidelines. In addition, data indicate that advanced age and low life expectancy at MTC diagnosis may serve as prognostic indicators to identify patients having a higher likelihood of missing the compulsory RET test.</p

RET C611Y Germline Variant in Multiple Endocrine Neoplasia Type 2A in Denmark 1930-2021: A Nationwide Study

Background: Multiple endocrine neoplasia type 2A (MEN 2A) is a rare hereditary cancer syndrome caused by pathogenic variants in the rearranged during transfection (RET) gene and is characterized by medullary thyroid carcinoma (MTC), pheochromocytoma (PHEO), primary hyperparathyroidism (PHPT), cutaneous lichen amyloidosis (CLA), and Hirschsprung’s disease. Phenotypic data on the RET C611Y variant remain sparse. Consequently, we aimed to establish a clinical risk profile. Methods: We conducted a nationwide study of all cases (n = 128) born after 1 January 1930 and recognized as carrying the RET C611Y variant in Denmark before 1 April 2021. Results: The median follow-up after birth was 47 years (range, 3–92). Age-related penetrance at age 70 years for MTC was 98% (CI, 91–100), for PHEO 24% (CI, 16–37), and for PHPT 10% (CI, 5–20). None had CLA or Hirschsprung’s disease. The age-related progression of MTC was significant (p &lt; 0.001). The median age at T0N0M0 was 11 years (2–62), at T1-4N0M0 was 37 years (12–65), at TxN1M0 was 47 years (16–79), and at TxNxM1 was 50 years (28–70). At the last follow-up, 56% of thyroidectomized cases (n = 103) were biochemically cured. Overall survival at 70 years was 74% (CI, 59–84). Conclusions: RET C611Y is associated with a very high penetrance of MTC and a low penetrance of PHEO and PHPT. CLA and Hirschsprung’s disease almost never occur. MTC seems moderately aggressive, but large variability can be seen. Overall survival may be comparable to that of the general population.</p

Survival and Long-Term Biochemical Cure in Medullary Thyroid Carcinoma in Denmark 1997-2014:A Nationwide Study

BACKGROUND: Survival of medullary thyroid carcinoma (MTC) subgroups in relation to the general population is poorly described. Data on the factors predicting long-term biochemical cure in MTC patients are nonexistent at a population level. A nationwide retrospective cohort study of MTC in Denmark from 1997 to 2014 was conducted, aiming to detect subgroups with survival similar to that of the general population and to identify prognostic factors for disease-specific survival and long-term biochemical cure.METHODS: The study included 220 patients identified from the nationwide Danish MTC cohort between 1997 and 2014. As a representative sample of the general population, a reference population matched 50:1 to the MTC cohort was used.RESULTS: Patients diagnosed with hereditary MTC by screening (hazard ratio [HR] = 1.5 [confidence interval (CI) 0.5-4.3]), patients without regional metastases (HR = 1.4 [CI 0.9-2.3]), and patients with stage I (HR = 1.3 [CI 0.6-3.1]), stage II (HR = 1.1 [CI 0.6-2.3]), and III (HR = 1.3 [CI 0.4-4.2]) disease had an overall survival similar to the reference population. On multivariate analysis, the presence of distant metastases (HR = 12.3 [CI 6.0-25.0]) predicted worse disease-specific survival, while the absence of regional lymph node metastases (odds ratio = 40.1 [CI 12.0-133.7]) was the only independent prognostic factor for long-term biochemical cure.CONCLUSIONS: Patients with hereditary MTC diagnosed by screening, patients without regional metastases, and patients with stages I, II, and III disease may have similar survival as the general population. The presence of distant metastases predicted worse disease-specific survival, while the absence of regional metastases predicted long-term biochemical cure.</p

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