Sporadic medullary thyroid carcinoma: clinical data from a university hospital

Serum Biochemical Markers for Medullary Thyroid Carcinoma: An Update

Introduction

Medullary thyroid carcinoma (MTC), a rare malignancy, requires early diagnosis for optimal patient outcomes. An important aspect of MTC diagnosis is the assessment of serum biomarkers. This review aimed to evaluate the use of serum biomarkers in the diagnosis, prognosis, and follow-up of MTC.

Methods

A thorough search of PubMed covering 1975 to 2022 was conducted to identify English-language articles on MTC serum biomarkers.

Results

The review revealed that calcitonin (Ctn) and carcinoembryonic antigen (CEA) remain the most important serum biomarkers for MTC diagnosis and management. Despite limited studies on procalcitonin (PCT), its stability and ability to exclude interference from inflammation make it a valuable potential marker of MTC. Although the positive rate of serum CA19-9 levels in MTC patients was not high, it can be used as an indicator of poor prognosis in advanced MTC. Other serum markers, including chromogranin A, gastrin-releasing peptide precursor, and neurospecific enolase, did not show any unique value in MTC diagnosis and management.

Conclusion

Taken together, this review emphasized the importance of serum biomarkers, particularly Ctn and CEA, in the diagnosis and management of MTC. PCT shows promise as a valuable potential marker, whereas CA19-9 can be used as a prognostic indicator of advanced MTC. Further research is needed to validate the significance of these serum biomarkers in MTC and determine the effects of confounding factors on their levels. Clinicians should consider using these markers in MTC diagnosis, prognosis, and follow-up, particularly for patients with advanced disease.

Medullary thyroid cancer: What is the optimal management of the lateral neck in a node negative patient at index operation?

BACKGROUND

Medullary thyroid cancer is a neuroendocrine malignancy that can occur sporadically or as the result of genomic rearranged during transfection mutations. Medullary thyroid cancer has a higher rate of metastasis than well-differentiated thyroid cancer. Lateral neck dissection is often performed, and its prophylactic use is controversial.

METHODS

Single-center, retrospective review (2000-2017) of patients undergoing primary surgical treatment for medullary thyroid cancer who had negative lateral neck imaging preoperatively. Demographics, genetic associations, clinical, and imaging findings were analyzed. Locoregional recurrence, overall recurrence, and overall survival were examined.

RESULTS

A total of 110 patients were identified, of which 18 underwent prophylactic lateral neck dissection and 92 did not. Age, sex distribution, preoperative calcitonin levels, and follow-up were similar among groups. Overall recurrence was 20% for no prophylactic lateral neck dissection and 39% for prophylactic lateral neck dissection (P = .46). Most recurrences were locoregional recurrence, 7.6% for no prophylactic lateral neck dissection versus 22% for prophylactic lateral neck dissection (P = .08), half of it being to the lateral neck in both groups. A total of 7 patients from the no prophylactic lateral neck dissection group required treatment for recurrences versus 4 patients in prophylactic lateral neck dissection group (P = .57). Overall survival at 5 years was similar, 43% the no prophylactic lateral neck dissection group and 31% for prophylactic lateral neck dissection group (P = .52).

CONCLUSION

Lateral neck dissection has no effect in decreasing locoregional or overall recurrences in medullary thyroid cancer and has no effect in overall survival when performed prophylactically at index surgical intervention.

A Review of the Significance in Measuring Preoperative and Postoperative Carcinoembryonic Antigen (CEA) Values in Patients with Medullary Thyroid Carcinoma (MTC)

Background and Objectives: Medullary thyroid carcinoma (MTC) accounts for 1–2% of all thyroid malignancies, and it originates from parafollicular “C” cells. Carcinoembryonic antigen (CEA) is a tumor marker, mainly for gastrointestinal malignancies. There are references in literature where elevated CEA levels may be the first finding in MTC. The aim of this study is to determine the importance of measuring preoperative and postoperative CEA values in patients with MTC and to define the clinical significance of the correlation between CEA and the origin of C cells. Materials and Methods: The existing and relevant literature was reviewed by searching for articles and specific keywords in the scientific databases of PubMedCentraland Google Scholar (till December 2020). Results: CEA has found its place, especially at the preoperative level, in the diagnostic approach of MTC. Preoperative CEA values >30 ng/mL indicate extra-thyroid disease, while CEA values >100 ng/mL are associated with lymph node involvement and distant metastases. The increase in CEA values preoperatively is associated with larger size of primary tumor, presence of lymph nodes, distant metastases and a poorer prognosis. The clinical significance of CEA values for the surgeon is the optimal planning of surgical treatment. In the recent literature, C cells seem to originate from the endoderm of the primitive anterior gut at the ultimobranchial bodies’ level. Conclusions: Although CEA is not a specific biomarker of the disease in MTC, itsmeasurement is useful in assessing the progression of the disease. The embryonic origin of C cells could explain the increased CEA values in MTC.

Small Cell Variant of Medullary Thyroid Carcinoma: A Possible Treatment

Small cell variant of medullary thyroid carcinoma is an extremely rare histologic entity with a paucity of data. As such, there is a lack of literature and clinical experience regarding this disease. In this report, we examine a case of small cell variant of medullary thyroid carcinoma that presented with intractable nausea, vomiting and diarrhea. While these symptoms were essentially refractory to the standard symptomatic treatment, further laboratory analysis revealed dramatically elevated calcitonin levels and mildly raised thyroid-stimulating hormone levels. Interestingly, repletion of thyroid hormone and treatment with lanreotide resulted in an abatement of our patient’s symptoms. This temporal clinical improvement highly suggests a potential role involving thyroid-stimulating hormone and calcitonin levels in the pathogenesis of this disease, and consequently suggests a role for thyroxine in treating the associated gastrointestinal symptoms. 

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.

Preoperative Clinical and Sonographic Predictors for Lateral Cervical Lymph Node Metastases in Sporadic Medullary Thyroid Carcinoma

BACKGROUND

Total thyroidectomy and cervical lymph node (LN) dissection is generally recommended in patients with medullary thyroid carcinoma (MTC). However, there is no clear evidence for whom to perform prophylactic lateral neck dissection in MTC patients without evident lateral cervical lymph node (LCLN) metastasis in preoperative images. This study evaluated the preoperative features for predicting the LCLN metastasis of MTC.

METHODS

The study included 26 MTC patients with LCLN metastasis at initial surgery (N1b group) and 47 MTC patients without any LN metastasis or recurrence of disease (N0-NED group). The association between LCLN metastasis and preoperative clinical and sonographic characteristics (size, location, solid component, shape, margin, echogenicity, calcification, and subcapsular location of the tumor) were evaluated.

RESULTS

There were no significant differences in age and sex between the N1b and N0-NED groups. Preoperative serum levels of calcitonin >65 pg/mL were associated with LCLN metastasis (p < 0.001). In preoperative neck ultrasonography (US), patients in the N1b group were more commonly found with a larger tumor (>1.5 cm) of irregular shape with a spiculated margin and a subcapsular location than those in the N0-NED group (p = 0.029, p < 0.001, p < 0.001, and p < 0.001, respectively). Increases in the number of these LCLN metastasis-related features were significantly associated with higher risk for LCLN metastasis (p < 0.001). The presence of two or more predictors was an appropriate cutoff point for predicting LCLN metastasis of MTC with 73.1% sensitivity and 91.5% specificity.

CONCLUSIONS

MTC tumors with high preoperative calcitonin levels (>65 pg/mL), larger size (>1.5 cm), irregular shape, spiculated margins, and subcapsular locations in the neck US are at higher risk for LCLN metastasis. MTC patents with fewer than two predictors might be suitable for treatment without prophylactic LCLN dissection.

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.

A differential diagnosis of inherited endocrine tumors and their tumor counterparts

Inherited endocrine tumors have been increasingly recognized in clinical practice, although some difficulties still exist in differentiating these conditions from their sporadic endocrine tumor counterparts. Here, we list the 12 main topics that could add helpful information and clues for performing an early differential diagnosis to distinguish between these conditions. The early diagnosis of patients with inherited endocrine tumors may be performed either clinically or by mutation analysis in at-risk individuals. Early detection usually has a large impact in tumor management, allowing preventive clinical or surgical therapy in most cases. Advice for the clinical and surgical management of inherited endocrine tumors is also discussed. In addition, recent clinical and genetic advances for 17 different forms of inherited endocrine tumors are briefly reviewed.

RET haplotype, not linked to the C620R activating mutation, associated with Hirschsprung disease in a novel MEN2 family

Hirschsprung disease is a congenital form of aganglionic megacolon that results from cristopathy. Hirschsprung disease usually occurs as a sporadic disease, although it may be associated with several inherited conditions, such as multiple endocrine neoplasia type 2. The rearranged during transfection (RET) proto-oncogene is the major susceptibility gene for Hirschsprung disease, and germline mutations in RET have been reported in up to 50% of the inherited forms of Hirschsprung disease and in 15-20% of sporadic cases of Hirschsprung disease. The prevalence of Hirschsprung disease in multiple endocrine neoplasia type 2 cases was recently determined to be 7.5% and the cooccurrence of Hirschsprung disease and multiple endocrine neoplasia type 2 has been reported in at least 22 families so far. It was initially thought that Hirschsprung disease could be due to disturbances in apoptosis or due to a tendency of the mutated RET receptor to be retained in the Golgi apparatus. Presently, there is strong evidence favoring the hypothesis that specific inactivating haplotypes play a key role in the fetal development of congenital megacolon/Hirschsprung disease. In the present study, we report the genetic findings in a novel family with multiple endocrine neoplasia type 2: a specific RET haplotype was documented in patients with Hirschsprung disease associated with medullary thyroid carcinoma, but it was absent in patients with only medullary thyroid carcinoma. Despite the limited number of cases, the present data favor the hypothesis that specific haplotypes not linked to RET germline mutations are the genetic causes of Hirschsprung disease.

Surgical approach to medullary thyroid carcinoma associated with multiple endocrine neoplasia type 2

We briefly review the surgical approaches to medullary thyroid carcinoma associated with multiple endocrine neoplasia type 2 (medullary thyroid carcinoma/multiple endocrine neoplasia type 2). The recommended surgical approaches are usually based on the age of the affected carrier/patient, tumor staging and the specific rearranged during transfection codon mutation. We have focused mainly on young children with no apparent disease who are carrying a germline rearranged during transfection mutation. Successful management of medullary thyroid carcinoma in these cases depends on early diagnosis and treatment. Total thyroidectomy should be performed before 6 months of age in infants carrying the rearranged during transfection 918 codon mutation, by the age of 3 years in rearranged during transfection 634 mutation carriers, at 5 years of age in carriers with level 3 risk rearranged during transfection mutations, and by the age of 10 years in level 4 risk rearranged during transfection mutations. Patients with thyroid tumor >5 mm detected by ultrasound, and basal calcitonin levels >40 pg/ml, frequently have cervical and upper mediastinal lymph node metastasis. In the latter patients, total thyroidectomy should be complemented by extensive lymph node dissection. Also, we briefly review our data from a large familial medullary thyroid carcinoma genealogy harboring a germline rearranged during transfection Cys620Arg mutation. All 14 screened carriers of the rearranged during transfection Cys620Arg mutation who underwent total thyroidectomy before the age of 12 years presented persistently undetectable serum levels of calcitonin (<2 pg/ml) during the follow-up period of 2-6 years. Although it is recommended that preventive total thyroidectomy in rearranged during transfection codon 620 mutation carriers is performed before the age of 5 years, in this particular family the surgical intervention performed before the age of 12 years led to an apparent biochemical cure.

High penetrance of pheochromocytoma associated with the novel C634Y/Y791F double germline mutation in the RET protooncogene

CONTEXT

Previous studies have shown that double RET mutations may be associated with unusual multiple endocrine neoplasia type 2 (MEN 2) phenotypes.

OBJECTIVE

Our objective was to report the clinical features of patients harboring a previously unreported double mutation of the RET gene and to characterize this mutation in vitro.

PATIENTS

Sixteen patients from four unrelated families and harboring the C634Y/Y791F double RET germline mutation were included in the study.

RESULTS

Large pheochromocytomas measuring 6.0-14 cm and weighing up to 640 g were identified in the four index cases. Three of the four tumors were bilateral. High penetrance of pheochromocytoma was also seen in the C634Y/Y791F-mutation-positive relatives (seven of nine, 77.7%). Of these, two cases had bilateral tumors, one presented with multifocal tumors, two cases had large tumors (>5 cm), and one case, which was diagnosed with a large (5.5 x 4.5 x 4.0 cm) pheochromocytoma, reported early onset of symptoms of the disease (14 yr old). The overall penetrance of pheochromocytoma was 84.6% (11 of 13). Development of medullary thyroid carcinoma in our patients seemed similar to that observed in patients with codon 634 mutations. Haplotype analysis demonstrated that the mutation did not arise from a common ancestor. In vitro studies showed the double C634Y/Y791F RET receptor was significantly more phosphorylated than either activated wild-type receptor or single C634Y and Y791F RET mutants.

CONCLUSIONS

Our data suggest that the natural history of the novel C634Y/Y791F double mutation carries a codon 634-like pattern of medullary thyroid carcinoma development, is associated with increased susceptibility to unusually large bilateral pheochromocytomas, and is likely more biologically active than each individual mutation.

Hypercalcitoninemia is not pathognomonic of medullary thyroid carcinoma

Hypercalcitoninemia has frequently been reported as a marker for medullary thyroid carcinoma. Currently, calcitonin measurements are mostly useful in the evaluation of tumor size and progression, and as an index of biochemical improvement of medullary thyroid carcinomas. Although measurement of calcitonin is a highly sensitive method for the detection of medullary thyroid carcinoma, it presents a low specificity for this tumor. Several physiologic and pathologic conditions other than medullary thyroid carcinoma have been associated with increased levels of calcitonin. Several cases of thyroid nodules associated with increased values of calcitonin are not medullary thyroid carcinomas, but rather are related to other conditions, such as hypercalcemias, hypergastrinemias, neuroendocrine tumors, renal insufficiency, papillary and follicular thyroid carcinomas, and goiter. Furthermore, prolonged treatment with omeprazole (>2-4 months), beta-blockers, glucocorticoids and potential secretagogues, have been associated with hypercalcitoninemia. An association between calcitonin levels and chronic auto-immune thyroiditis remains controversial. Patients with calcitonin levels >100 pg/mL have a high risk for medullary thyroid carcinoma (approximately 90%-100%), whereas patients with values from 10 to 100 pg/mL (normal values: <8.5 pg/mL for men, <5.0 pg/mL for women; immunochemiluminometric assay) have a <25% risk for medullary thyroid carcinoma.In multiple endocrine neoplasia type 2 (MEN2), RET mutation analysis is the gold-standard for the recommendation of total preventive thyroidectomy to relatives at risk of harboring a germline RET mutation (50%). False-positive calcitonin results within MEN2 families have led to incorrect indications of preventive total thyroidectomy to RET mutation negative relatives. In this review, we focus on the differential diagnosis of hypercalcitoninemia, underlining its importance for the avoidance of misdiagnosis of medullary thyroid carcinoma and consequent incorrect recommendation for thyroid surgery.