MicroRNAs in thyroid cancer with focus on medullary thyroid carcinoma:potential therapeutic targets and diagnostic/prognostic markers and web based tools

This review aimed to describe the inculpation of microRNAs(miRNAs)in thyroid cancer(TC)and its subtypes,mainly medullary thyroid carcinoma(MTC),and to outline web-based tools and databases for bioinformatics analysis of miRNAs in TC.Additionally,the capacity of miRNAs to serve as therapeutic targets and biomarkers in TC management will be discussed.This review is based on a literature search of relevant articles on the role of miRNAs in TC and its subtypes,mainly MTC.Additionally,web-based tools and databases for bioinformatics analysis of miRNAs in TC were identified and described.MiRNAs can perform as oncomiRs or antioncoges,relying on the target mRNAs they regulate.MiRNA replacement therapy using miRNA mimics or antimiRs that aim to suppress the function of certain miRNAs can be applied to correct miRNAs aberrantly expressed in diseases,particularly in cancer.MiRNAs are involved in the modulation of fundamental pathways related to cancer,resembling cell cycle checkpoints and DNA repair pathways.MiRNAs are also rather stable and can reliably be detected in different types of biological materials,rendering them favorable diagnosis and prognosis biomarkers as well.MiRNAs have emerged as promising tools for evaluating medical outcomes in TC and as possible therapeutic targets.The contribution of miRNAs in thyroid cancer,particularly MTC,is an active area of research,and the utility of web applications and databases for the biological data analysis of miRNAs in TC is becoming increasingly important.

Investigation of Calcitonin and Calcitonin Gene-related Peptide in 88 Cases of Medullary Thyroid Carcinoma

Objective： To investigate the changes of calcitonin （CT） and calcitonin gene-related peptide （CGRP） in patients with medullary thyroid carcinoma （MTC）. Methods： Fifty-eight cases of MTC were selected and the relationship between the CT levels and metastasis was investigated. The immunohistochemical method was used to detect the expression of CT and CGRP in the 58 samples of MTC tissues. The CT and CGRP in 30 newly diagnosed MTC inpatients were measured before operation and in the first few days after operation using a radioimmunoassy. Results： （1） The rate of residual tumor had a significant difference between the normal serum CT group one month after operation and the elevated group at the same period （P〈0.01）. （2） Immunohistochemical study revealed the positive rate of CT was about 98%, and that of the CGRP was 87.8%. （3） Part of the patients had an elevated CGRP levels while CT levels was normal. （4） The serum CT levels were decreased to a stable range one week after operation. Conclusion： CT is a useful index to evaluate the efficacy of surgical treatment. The measurement of serum CGRP is helpful in the diagnosis of MTC, especially for those whose preoperative CT levels are normal.

Do medullary thyroid carcinoma patients with high calcitonin require bilateral neck lymph node clearance?A case report

BACKGROUND In clinical work,85%-90%of malignant thyroid diseases are papillary thyroid cancer(PTC);thus,clinicians neglect other types of thyroid cancer,such as medullary thyroid carcinoma(MTC).CASE SUMMARY We report a 53-year-old female patient with a preoperative calcitonin level of 345 pg/mL.There was no definitive diagnosis of MTC by preoperative fine-needle aspiration cytology or intraoperative frozen pathology,but the presence of PTC and MTC was confirmed by postoperative paraffin pathology.The patient underwent total thyroidectomy and bilateral central lymph node dissection.Close follow-up at 1.5 years after surgery revealed no signs of recurrence or metastasis.CONCLUSION The issue in clinical work-up regarding types of thyroid cancer provides a novel and challenging idea for the surgical treatment of MTC.In the absence of central lymph node metastasis,it is worth addressing whether patients with high calcitonin can undergo total thyroidectomy and bilateral central lymph node dissection without bilateral lateral neck lymph node dissection.

Effects of rearranged during transfection mutation on calcitonin and procalcitonin expression in sporadic medullary thyroid carcinoma

Objective The aim of this study was to investigate the effects of rearranged during transfection(RET)mutation on the expressions of calcitonin(CTn)and procalcitonin(PCT)in sporadic medullary thyroid carcinoma(SMTC).Methods RET mutation was detected by polymerase chain reaction direct sequencing in 64 cases of SMTC,and the expression levels of CTn and PCT in SMTC tissues were detected using the immunohistochemical streptavidin-perosidase(SP)method.The effect of RET mutations on the expression of CTn and PCT along with its relationship with clinicopathological parameters were analyzed.Results The expression rates of CTn and PCT in SMTC tissues were 90.6%(58/64)and 67.2%(43/64),respectively.CTn and PCT expression were found to be associated with tumor size and lymph node metastasis(P<0.05)but not with gender,age,or tumor capsule invasion(P>0.05).There was a significant correlation between CTn and PCT expression(r=0.269,P=0.041),and the intensity of positive CTn expression was positively correlated with RET mutation(r=0.507,P=0.000).However,PCT expression was not associated with RET mutation(r=0.188,P=0.136).Conclusion High expression of CTn and PCT was associated with the progression of medullary carcinoma,and the intensity of CTn expression was associated with RET mutation.PCT may provide valuable information for the diagnosis and prognosis of SMTC.

Studies on surgical methods for sporadic micromedullary thyroid carcinoma

Background:To observe the changes in serum calcitonin levels after application of different surgical methods for primary medullary thyroid microcarcinoma(MTMC)and explore a more reasonable surgical method.Methods:A retrospective analysis of 36 patients with MTMC,16 in group A and 20 in group B,was performed.In group A,tumors were single and confined to the thyroid lobe,and thyroid lobectomy with isthmusectomy was performed.In group B,tumors were in the isthmus or invaded the thyroid gland,or there were multiple foci in bilateral lobes,and patients with primary foci underwent total thyroidectomy.The median follow-up time was 3.6 years.Clinical and pathological characteristics and changes in serum calcitonin(CTn)and carcinoembryonic antigen levels after the surgery were compared between the 2 groups.Results:The difference in the biochemical cure rate after surgery was statistically significant between patients with preoperative serum calcitonin levels<150 pg/mL and≥150 pg/mL(P<0.01).No significant differences in the biochemical cure rates and serum calcitonin levels were noted at different time points after surgery between group A and group B(P>0.05).One recurrence and metastasis were observed in each group after surgery.Conclusions:After performing different surgical methods for the primary foci of MTMC,the changes in serum calcitonin and carcinoembryonic antigen levels are similar.Especially for patients with single foci confined to the thyroid lobe without lateral cervical lymph node metastasis and with serum calcitonin levels<150 pg/mL,the unilateral thyroid lobectomy with isthmectomy can achieve the same therapeutic effect and biochemical cure rate as total thyroidectomy.

Gastric Metastasis of Atypical Medullary Carcinoma from Breast:a Case Report

METASTATIC gastric tumors are clinically uncommon,and metastatic gastric cancer from breast cancer was rarely reported.Here we report a case of gastric metastasis of atypical medullary carcinoma from breast.

A Case of Medullary Thyroid Carcinoma Combined with Papillary Microcarcinoma and Literature Review

Background: The histologic type of thyroid carcinomas includes follicular, papillary carcinomas, and medullary carcinomas. The reports about the histological, immunohistochemical, and ultrastructural characteristics of each kind of thyroid carcinomas were common, but the simultaneous occurrence of a medullary and papillary carcinoma as 2 distinct tumors has been reported extremely rarely. Objects: To explore the pathogenesis, clinicopathological characteristics, immunohistochemical phenotype, and pathological diagnosis of medullary thyroid carcinoma combined with papillary thyroid microcarcinoma. Methods: The clinicopathological characteristics and immunohistochemical phenotype of a patient with left medullary thyroid carcinoma combined with right papillary thyroid microcarcinoma were retrospectively studied. Then, relevant literature was thus reviewed. Results: General appearance: The size of the left thyroid lobe was 2.5 × 2 × 1 cm, the cut surface was gray and red, and a nodule with a diameter of 1.3 cm could be observed. The cut surface of the nodule was gray and yellow, solid, and hard. The size of the right lobe of the thyroid gland was 0.7 × 0.6 × 0.5 cm, and a gray nodule with a diameter of 0.4 cm was seen on the cut surface. The cut surface of the nodule was gray, solid, and hard. Observation under the microscope: the left nodular tumor cells were round, oval, or plasma cell-like, some areas were arranged in nests, and some areas were arranged in beams. Calcification and sheet-like eosinophilic amyloid deposits could be seen in the stroma. The nodule on the right showed a branched papillary structure, the covering cells on the surface of the nipple were ground glass-like nuclei, and nuclear grooves and pseudo-inclusion bodies in the nucleus could be observed. Immunohistochemistry: left lobe tumor cells Calcitonin, CEA, TTF-1, CD56, CgA, and Syn are all (+), CK19 and TG were both (&#8722;);right lobe tumor cells CK19 and TG are both (+), Calcitonin, CD56, CgA, and Syn are all (&#8722;). Conclusions: The origin, clinicopathological manifestations, and immunophenotypes of medullary thyroid carcinoma and papillary thyroid carcinoma are different. It is relatively rare for the two to occur at the same time. The diagnosis mainly depends on the microscopic morphology and immunophenotype characteristics.

Mixed Medullary-follicular Thyroid Carcinoma： Report of a Case and Review of the Literarture

Mixed medullary-follicular carcinomas （MMFCs） are tumors of the thyroid that display morphological and immunohistochemical features of both medullary and follicular neoplasms. These tumors are rare and less than 40 cases have been described in the literature since the early 1980s The term medullary-follicular thyroid carcinoma denotes a tumor which exhibits the features of a medullary carcinoma and shows positive expression of calcitonin on immunohistochemistry. It is a follicular-derived thyroid carcinoma and is positive for thyroglobulin expression within the same tumor. Most reported cases have lymph node involvement at the time of diagnosis. In cases having disease progression, distant metastases develop in the lung, liver, mediastinum and bone. We report a case of a male patient with mixed medullary-follicular thyroid carcinoma and a review of the literature.

Is new American Thyroid Association risk classification for hereditary medullary thyroid carcinoma applicable to Chinese patients? A single-center study

Objective: The American Thyroid Association (ATA) proposed a new risk classification for hereditary medullary thyroid carcinoma (MTC) in 2015. This study aimed to assess whether the new guidelines are suitable for the Chinese population, and reported our experience on prophylactic thyroidectomy. Methods: A total of 73 patients from 22 families were screened as rearranged during transfection (RET) mutation carriers from 2010 to 2016 in Cancer Hospital, Chinese Academy of Medical Science; the medical history for each patient was collected. Based on the initial treatment, we identified the risk factors for poor prognosis by univariate and multivariate logistic regression. Then, 4 RET mutation carriers were enrolled for prophylactic thyroidectomy, and their pathological data and follow-up outcomes were recorded. Results: In univariate and multivariate logistic regression analyses, age at initial surgery and risk classification were significant risk factors for stage III/IV hereditary MTC at initial diagnosis. The likelihood was increased by 11.6% per year of age at initial surgery [95% confidence interval (95% CI), 1.040-1.198; P=0.002). It was 7.888 times more likely to have III/IV stage disease for ATA highest risk patients, compared to ATA moderate risk individuals (95% CI, 1.607-38.717; P=0.003). Postoperative pathological results showed all 4 multiple endocrine neoplasia type 2A (MEN2A) patients had C-cell hyperplasia (CCH); multifocal malignancies were detected in 3 of them. All 4 patients were cured biochemically, and none developed permanent hypoparathyroidism. Conclusions: In Chinese individuals, hereditary MTC aggressiveness is in line with the new ATA risk classification. Germline RET gene mutation carriers should undergo prophylactic thyroidectomy according to basal serum calcitonin levels.

Acute coronary syndrome: a rare case of multiple endocrine neoplasia syndromes with pheochromocytoma and medullary thyroid carcinoma

Pheochromocytoma is a tumor arising from neuroectodermal chromaffin tissues in the adrenal gland or extra-adrenal paraganglia(paragangliomas). The prevalence of the tumor is 0.1%-0.6% in the hypertensive population, of which 10%-20% are malignant. Pheochromocytoma produces, stores, and secretes catecholamines, as well as leads to hypertensive crisis, arrhythmia, angina, and acute myocardial infarction without coronary artery diseases. We report a case of acute coronary syndrome(ACS) with a final diagnosis of multiple endocrine neoplasia with pheochromocytoma and medullary thyroid carcinoma(MTC).

Effect of parathyroid hormone on apoptosis of human medullary thyroid carcinoma cells

Objective The aim of the study was to investigate the effect of parathyroid hormone(PTH) on the apoptosis of human medullary thyroid carcinoma(MTC) cells.Methods In vitro cultured medullary thyroid carcinoma cell lines were treated with parathyroid hormone and parathyroid hormone receptor-monoclonal antibody,and the apoptosis of cells was detected by flow cytometry.Results The cell morphology changed significantly after treatment based on the observation using the inverted phase-contrast microscope.Various concentrations of parathyroid hormone and parathyroid hormone receptor-monoclonal antibody effectively induced apoptosis in a time-and concentrationdependent manner.When the concentration of parathyroid hormone was 2.0 μmol/L and that of parathyroid hormone receptor-monoclonal antibody was 1.0 μmol/L,the apoptotic rate was 13.24% and 20.78%,respectively,representing a statistically significant difference from that of the control cells(P < 0.05).Conclusion PTH plays a role in inducing apoptosis of human MTC cells.

Recurrent medullary thyroid carcinoma treated with percutaneous ultrasound-guided radiofrequency ablation:A case report

BACKGROUND Treatment for neck lymph node metastases after adequate initial surgery in medullary thyroid carcinoma(MTC)has been controversial.Ultrasound(US)-guided radiofrequency ablation(RFA)has been widely used in recurrent welldifferentiated thyroid carcinoma.Here,we report for the first time the use of RFA in a patient with recurrent MTC.CASE SUMMARY We report the case of a 56-year-old woman with cervical lymph node metastases of MTC.Four years previously,she had undergone a total thyroidectomy and neck lymph node dissection.A neck US revealed many enlarged nodes during the follow-up period.Moreover,the serum calcitonin jumped to 198.17 pg/mL,which strongly indicated the recurrence of MTC.Subsequently,two metastatic lymph nodes were confirmed by US-guided fine-needle aspiration-cytology and fineneedle aspiration-calcitonin,and then the patient was treated with RFA.Four months later,the neck US and a contrast-enhanced US showed obvious shrinkage in the ablation zones,and the serum calcitonin dropped to 11.80 pg/mL.CONCLUSION This case suggests that RFA may be an effective and safe treatment for local recurrent MTC.

Inhibition effects of parathyroid hormone on human medullary thyroid carcinoma cells

Objective： The purpose of the study was to investigate the effects of parathyroid hormone and parathyroid hormone receptor monoclonal antibody on in vitro growth and proliferation of human medullary thyroid carcinoma cell lines. Methods： The medullary thyroid carcinoma cell line was cultured in vitro, with parathyroid hormone and parathyroid hormone receptor monoclonal antibody treatment intervention, the growth of the cells was observed under an inverted contrast micro scope, the MTT assay was used to detect the cell growth inhibition rate. Results： Under the inverted contrast microscope, the cells changed significantly, the parathyroid hormone and parathyroid hormone receptor monoclonal antibodies can effectively inhibit the proliferation of medullary thyroid cancer cells in a time and dose dependent. When parathyroid hormone concentra tion reached a concentration of 2.0 IJmol/L, the parathyroid hormone receptor monoclonal antibody reached a concentration of 1.0 μmol/L, the cell growth was most significantly inhibited （P 〈 0.05）. Conclusion： Parathyroid hormone and parathyroid hormone receptor monoclonal antibody were able to inhibit the proliferation of medullary thyroid carcinoma cells and signifi cantly reduce the proliferation index.

Novel p.C620L RET Mutation Detected in a Patient with Medullary Thyroid Carcinoma

A patient with an apparent sporadic medullary thyroid carcinoma was tested for RET germline mutations by Sanger sequencing of RET exons 10, 11, and 13-16. The patient was heterozygous for two known mutations causative of Multiple Endocrine Neoplasia type 2 disorder, and both mutations were within codon 620 of RET exon 10, c.1859G > T (p.C620F) and c.1860C > G (p.C620W). In order to determine if these adjacent mutations were in cis or in trans, an unlabeled probe method and high-resolution melting analysis were utilized. The mutations were confirmed to occur in cis, representing a novel mutation, c.1859_1860delinsTG (p.C620L). Sanger sequencing of parental samples did not identify any changes at codon 620, so the p.C620L mutation is also de novo. The early age of onset for medullary thyroid carcinoma and the presence of lymph node metastasis in this patient suggests individuals with the p.C620L mutation should be treated and screened (for pheochromocytomas and parathyroid hyperplasia) as Multiple Endocrine Neoplasia type 2 patients with other RET codon 620 mutations (American Thyroid Association risk level B).

Ambiguous clear cell carcinoma in medullary sponge kidney:A case report

Medullary sponge kidney(MSK)is a characteristic renal malformation,with a relatively low incidence.Radiologically,identification of MSK is sometimes ambiguous when compared to a renal mass.Here,we report a novel renal clear cell carcinoma in MSK,and discuss our approach to treatment.We recommended that a preoperative biopsy should be performed,followed by a comprehensive discussion regarding the appropriate perioperative preparations and careful surgical techniques that should be performed for this complex disease.

Incidental diagnosis of medullary thyroid carcinoma due to persistently elevated procalcitonin in a patient with COVID-19 pneumonia:A case report

BACKGROUND Procalcitonin(Pct)is a common biomarker in clinical practice,especially in the era of coronavirus disease 2019(COVID-19)infection.Although it is frequently used for the diagnosis and prognostication of bacterial infections or sepsis,it is also elevated in a few other conditions,including medullary thyroid carcinoma(MTC).CASE SUMMARY A 43-year-old female presented with moderately severe COVID-19 pneumonia in April 2021.She gradually recovered clinically;however,despite normalization of other inflammatory markers,Pct levels remained persistently elevated.Further workup identified the cause as left lobe MTC with locoregional metastasis.Calcitonin levels were high,and carcinoembryonic antigen levels were normal.The patient underwent total thyroidectomy and neck dissection,which was followed by another radical neck dissection due to residual disease.Currently,she is doing well,nearly having completed her course of external beam radiotherapy with no recurrence.Pct is well documented as a screening tool for MTC,especially because of its stable nature compared to calcitonin in the community settings.It is important to keep in mind the differential diagnosis of MTC in patients with persistently elevated Pct levels despite normal levels of other acute phase reactants.To the best of our knowledge,this is the first report from Asia of such an incidental diagnosis of MTC due to persistently elevated Pct levels in a patient with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection.CONCLUSION Persistently elevated Pct levels can occur in any pro-inflammatory state including infections,sepsis,or acute respiratory distress syndrome.In the current setting,SARS-CoV-2 infection is one such clinical scenario,and in rare situations of persistent elevation,MTC may need to be ruled out.

Melanotic medullary carcinoma of thyroid:a case report

Melanotic medullary carcinoma is extremely rare. We described a 35-year-old man who was found swelling in the left neck accidently, and no clinic evidences. A left total and right subtotal thyroidectomy and neck lymph nodes dissection were done. Lymph nodes metastasis was not shown. Postoperative of four months, computerized tomography scan liver showed multiple focal lesion. Microscopic examination showed that abundant melanin pigmentation was observed in many of tumor cells. Tumor cells were diffusely immunopositive for vimentin, CK, CgA, syn, CEA, Calcitonin, HMB45, S-100 and negative for TG, TTF-1. Melanotic medullary carcinoma is very rare. It is necessary to report more cases for exact biological behavior and prognosis.

Tumor-Associated Lymphatic and Venous Vessels in Medullary Thyroid Carcinomas

Objective: Medullary thyroid carcinomas (MTCs) invade local lymph node through lymphatic vessels and metastasize to distant organs hematogenously and account for a significant mortality. There are possibly increased lymphatic and venous vessels, through which the tumor spreads to lymph nodes and distant organs. Materials and Methods: By immunocytochemical staining for lymphatic and venous vessels, MTC lesions with adjacent normal thyroid and both normal and metastatic lymph nodes were studied for the peritumoral lymphatic and venous vessels, which were morphometrically compared with those of normal thyroid and lymph nodes. Sixteen cases of MTC cases with adjacent thyroid tissues and attached lymph nodes were immunocytochemically stained for lymphatic vessels using lymphatic vessel hyaluronan receptor (LYVE-1) and venous vessels for factor VIII (F-8). The immunostained sections of MTC lesions and metastatic lymph nodes were morphometrically compared for the number and sizes of the vessels with those of normal thyroid tissues and lymph nodes. Results: Significantly increased lymphatic vessels and markedly increased blood vessels were identified in many MTC cases at the peritumoral tissues and metastatic lymph nodes whereas a few lymphatic vessels and no venous vessels were identified in midst of MTCs. The irregular peritumoral lymphatic vessels resembled that of immature lymphatic vessels observed in papillary thyroid carcinomas and increased irregularly, entrapped venous vessels in peritumoral tissues resembled those observed in follicular thyroid carcinomas. Conclusion: The significantly increased lymphatic vessels and markedly increased venous vessels in the peritumoral thyroid tissue support a propensity of MTCs for providing an easy access of tumor cells to both lymphatic spread to the regional lymph nodes and venous spread to distant organs with further tumor spread through metastatic lymph nodes by moderately increased lymphatic and venous vessels.

Irreversible electroporation for metastatic pancreatic carcinoma with liver metastasis:What does the evidence say

Irreversible electroporation is a promising non-thermal ablation method that has been shown to increase overall survival in locally advanced pancreatic cancer in some studies.However,higher quality studies with proper controls and randomization are required to establish its superiority when added with neoadjuvant chemotherapy over the current management of choice,which is chemotherapy alone.Further studies are required before establishment of any survival benefit in metastatic pancreatic carcinoma,and such evidence is lacking at present.

Cetuximab combined with chemotherapy for simultaneous esophageal squamous cell carcinoma and colon adenocarcinoma:A case report

BACKGROUND Multiple primary carcinomas(MPCs)are defined as two or more independent primary cancers that occur simultaneously or sequentially in the same individual.Synchronous MPCs are rarer than solitary cancers or metachronous MPCs.Accurate diagnoses of synchronous MPCs and the choice of treatment are critical for successful outcomes in these cases.CASE SUMMARY A 64-year-old patient presented with dysphagia,without obvious cause.A diagnosis of synchronous esophageal squamous cell carcinoma and colon adenocarcinoma with liver metastasis was confirmed based on examination and laboratory results.After multi-disciplinary consultations,combination chemotherapy(a 3-wk cycle with oxaliplatin 212 mg administered on day 1 and capecitabine 1.5 g twice daily on days 1-14)and esophageal cancer radiotherapy were initiated.Based on the results of genetic testing,we switched to a regimen of leucovorin+fluorouracil+oxaliplatin and cetuximab regimen for 8 cycles.Subsequently,capecitabine and bevacizumab were administered until the most recent follow-up,at which the tumor remained stable.CONCLUSION Successful cetuximab chemotherapy treatment provides a reference for the nonoperative and homogeneous treatment of different pathological types of synchronous MCPs.