Long-term clinical and biochemical follow-up in medullary thyroid carcinoma: a single institution's experience over 20 years

Molecular diagnostic approaches in detecting rearranged during transfection oncogene mutations in multiple endocrine neoplasia type 2

Different types of neuroendocrine cancer, including medullary thyroid cancer (MTC) and thyroid C-cell hyperplasia, are part of multiple endocrine neoplasia type 2 (MEN2). A proto-oncogene mutation of the rearranged during transfection (RET) gene changes the way that receptor tyrosine kinases work. Multiple endocrine neoplasia, a pathological condition, involves these kinases. When the RET protooncogene changes, it can cause endocrine adenomas and hyperplasia to happen at the same time or one after the other. Pheochromocytoma, medullary thyroid carcinoma, and hyperparathyroidism, alone or in combination, are present in MEN2A patients. Some patients may also have skin lichen amyloidosis or Hirschsprung's disease. Patients with MEN2A often present with MTC. MTC is aggressive and has the worst prognosis, as most patients exhibit lymph node metastasis. MTC is one of the important causes of death in patients with MEN2A. RET mutation analysis aids in identifying MEN2A symptoms and monitoring levels of calcium, thyroid hormones, calcitonin, normetanephrine, fractionated metanephrines, and parathyroid hormone. The earlier diagnosis of MTC significantly improves survival and prompts better management of MEN2A. In this editorial, we will discuss the significance of molecular diagnostic approaches in detecting RET oncogene mutations in MEN2A.

Sporadic and Familial Medullary Thyroid Carcinoma: A Retrospective Single Center Study on Presentation and Outcome

BACKGROUND

Medullary Thyroid Carcinoma (MTC) is a neuroendocrine tumor that arises from the thyroid C-cells. Most cases are sporadic (sMTC) while, approximately 25%, are hereditary (hMTC) due to germline mutations of REarranged during Transfection (RET) gene mutations and manifest in the framework of multiple endocrine neoplasia (MEN) 2A or 2B, or as pure familial MTC syndrome (FMTC).

OBJECTIVE

The aim of this study is to evaluate the clinical, histopathological, biochemical and outcome differences between sMTC and hMTC.

METHODS

Retrospective analysis of a consecutive series of 102 patients with histologically proven MTC diagnosed in the period between 2000 and 2022. For the analysis patients with MTC diagnosed during screening through genetic test were excluded.

RESULTS

Patients with hMTC had higher incidence of multifocal and bilateral MTC and younger age at diagnosis. We did not found differences on tumor stage at diagnosis between sMTC and hMTC, such as time to progression and rate of persistent and recurrent disease. At univariate analysis, factors associated with persistent and recurrent disease during follow-up in patients with sMTC were tumor size, extrathyroidal extension, presence of lymph node metastases at diagnosis, pre- and post-operative calcitonin, post-operative CEA; in patients with hMTC, features associated with persistent and recurrent disease were lymph node metastases, post-operative calcitonin and pre- and post-operative CEA values.

CONCLUSION

Patients with hMTC and sMTC had similar histopathological characteristics and clinical outcome.

The neurotransmitter calcitonin gene-related peptide shapes an immunosuppressive microenvironment in medullary thyroid cancer

Neurotransmitters are key modulators in neuro-immune circuits and have been linked to tumor progression. Medullary thyroid cancer (MTC), an aggressive neuroendocrine tumor, expresses neurotransmitter calcitonin gene-related peptide (CGRP), is insensitive to chemo- and radiotherapies, and the effectiveness of immunotherapies remains unknown. Thus, a comprehensive analysis of the tumor microenvironment would facilitate effective therapies and provide evidence on CGRP's function outside the nervous system. Here, we compare the single-cell landscape of MTC and papillary thyroid cancer (PTC) and find that expression of CGRP in MTC is associated with dendritic cell (DC) abnormal development characterized by activation of cAMP related pathways and high levels of Kruppel Like Factor 2 (KLF2), correlated with an impaired activity of tumor infiltrating T cells. A CGRP receptor antagonist could offset CGRP detrimental impact on DC development in vitro. Our study provides insights of the MTC immunosuppressive microenvironment, and proposes CGRP receptor as a potential therapeutic target.

Biomarker identification of medullary thyroid carcinoma from gene expression profiles considering without-treatment and with-treatment studies-A bioinformatics approach

Medullary thyroid carcinoma (MTC) is a neuroendocrine tumor derived from parafollicular thyroid gland cells. In both hereditary MTC and sporadic forms, genetic changes result in fundamental changes, and prognosis and mutational status are highly correlated. In this work, biomarker genes (DEGs and DEmiRNAs) for MTC will be computationally identified in order to help in their diagnosis and treatment. The gene expression profiles of two different types of studies, namely without-treatment (wo-trt) and with-treatment (w-trt), are considered for discovering biomarkers. The datasets were retrieved from the GEO database, and the DEGs and DEmiRNAs were analyzed using ExpressAnalyst and GEO2R. The functional analysis of DEGs and DEmiRNAs was performed, and most of the pathways enriched related to thyroid oncological pathways such as MAPK pathway,mTOR pathway, and PI3K-AKT Signaling pathway. Through this conclusion, the RET gene was upregulated wo-trt; the dinaciclib treatment RET gene was down-regulated computationally. To optimize the therapeutic targeting of RET, greater research into the mechanisms regulating RET transcription is necessary.

Metastatic medullary thyroid carcinoma (MTC): disease course, treatment modalities and factors predisposing for drug resistance

PURPOSE

MTC has varying clinical course. In cases with metastatic disease (meta-MTC) further therapeutic modalities (locoregional and/or Tyrosine-Kinase-Inhibitors, TKIs) are needed. Clinical features, disease progression, response to therapy and possible factors predisposing to TKIs response-resistance in meta-MTCs were investigated.

METHODS

Out of 338 MTC patients 54 had meta-MTC and were followed for 0.7-46 years (median 10.5); therapeutic interventions and response to therapy were recorded retrospectively.

RESULTS

Of 54 meta-MTC patients, 34/54 were men, 44/54 sporadic (age-at-diagnosis 47 ± 17.4 years, range: 5-78). Distant metastases at diagnosis were present in 12/54 (≥2 loci in 8/12), 7/12 received TKIs; During follow-up metastases occurred in 42/54 (within 0.6-25 years from diagnosis, median 5 yrs). Locoregional therapies were administered to 44/54 (81.5%) and TKIs to 40/54 (74.1%). Vandetanib was administered in 30 patients (24 as first-line therapy). The median progression-free-survival, PFS) was 48 months (range 4-120), partial response (PR): 26.7%, stable disease (SD): 23.3%, progressive disease (PD): 50.0%, cancer-specific survival: 44.8%, (16 in ongoing-therapy). More favorable disease course was recorded in familial-MTC compared to sporadic (p = 0.02) and in those patients with serious-adverse-events (SAEs) under treatment (p = 0.027). Those with biochemical progression under vandetanib, later showed more frequently structural progression (p = 0.007). Ten patients received cabozantinib (8/10 as second-line therapy, median PFS:11 months (3-36 months), 8/10 died). Three RET-mutant patients received selpercatinib; all showed PR. Within the total follow-up period, the response to therapy was: PR: 8/54 (14.8%), SD: 15/54 (27.8%), PD: 31/54 (57.4%), cancer-specific survival 46.3%. Mortality was higher in older patients (≥60 years) compared to younger ones (<60 yrs) (83.3 vs 45.2%, p = 0.021). Outcome was better in familial-MTC vs sporadic (PR: 50 vs 6.8%, SD: 20 vs 29.5%, PD: 30 vs 59.1%, p = 0.007).

CONCLUSIONS

Meta-MTCs treatment results in disease stabilization in 42.6% during a median 10.5 year follow-up. Combination of locoregional and systemic therapies may result in more favorable PFS. Family history, younger age, SAEs may predict better response; biochemical escape under TKI needs to be followed-up closely as it may indicate disease progression.

Indoleamine 2,3-dioxygenase 2 immunohistochemical expression in medullary thyroid carcinoma: implications in prognosis and immunomodulatory effects

BACKGROUND

The linkage between IDO2 expression and cancer progression is still unclear, particularly in medullary thyroid carcinoma (MTC). Our purpose is to unveil the potential correlations between IDO2 status, clinical-pathological parameters, patients' prognosis, and the possible immunomodulatory functions in MTC.

METHODS

Immunohistochemical expression levels of IDO2 were evaluated in the resected MTC surgical specimens and corresponding lymph nodes. CD4 + T cell infiltration was also evaluated by immunohistochemical analysis in the MTC tissues. The association of the IDO2 expression level with clinicopathologic characteristics, overall survival (OS)/recurrence-free survival (RFS), and CD4 + T cell infiltration were retrospectively investigated.

RESULTS

High expression of IDO2 is closely associated with more aggressive clinicopathological features, such as multifocality, ETE, a higher pT stage and especially a higher pN stage. Moreover, a significant difference in RFS was observed between the IDO2-high and IDO2-low groups. IDO2 expression of lymph node tissues was significantly related to the metastasis status. Furthermore, we found that IDO2 expression is negatively correlated with CD4 + T cell infiltrations in MTC tissues.

CONCLUSION

The expression level of IDO2 is associated with aggressive characteristics and is predictive of poor prognosis in patients with MTC. Also, an interesting observation is that IDO2 involvement in MTC showed a moderate sexual dimorphism, of which female patients tend to be more affected by IDO2 status. Moreover, our results showed the potential immunomodulatory functions of IDO2. The close relationship between IDO2 and CD4 + T cell infiltration in the MTC microenvironment, together with its potential prognostic implications, makes it possible for IDO2 to serve as an alternative drug target in cancer immunotherapy and as a new prognostic tool.

Surgical selection and prognostic analysis in patients with unilateral sporadic medullary thyroid carcinoma

PURPOSE

The extent of thyroid surgery and cervical lymph node dissection of unilateral sporadic medullary thyroid carcinoma (sMTC) is still controversial, and the aim of this study was to investigate whether hemithyroidectomy was adequate as a locally curative surgery for patients with unilateral sMTC.

METHODS

This study is a retrospective case series of patients with sMTC who underwent curative total thyroidectomy or hemithyroidectomy in our institution from January 2011 to December 2019.

RESULTS

In total, 129 patients who met the inclusion criteria were enrolled including 49 (38.0%) patients who underwent total thyroidectomy and 80 (62.0%) patients who underwent hemithyroidectomy. About 80 (62.0%) patients achieved a biochemical cure (BC), whereas there was no significant difference between two groups in biochemical cure rate (61.2% versus 62.5%, P = 0.885). A logistic regression analysis showed a strong negative correlation between the factors of preoperative calcitonin level and pTNM stage and biochemical cure. In the log-rank test, no significant difference in OS (P = 0.314) and DFS (P = 0.409) was found between the two surgical groups. Lateral cervical lymph node metastasis and pTNM stage were significant prognostic factors affecting DFS in univariate analysis; moreover, absence of biochemical cure, tumor size ≥ 4 cm and lateral cervical lymph node metastasis were independent risk factors of unilateral sMTC patients in our analysis.

CONCLUSION

For patients with unilateral sMTC, hemithyroidectomy was adequate as a locally curative surgery, because the patients underwent total thyroidectomy did not benefit more from it in the aspects of BC/OS/RFS, while the postoperative increasing incidence rate of postoperative hypocalcemia could not improve patients' quality of life.

Multiple endocrine neoplasia 2: an overview

This review article discusses the diagnosis and treatment of patients with multiple endocrine neoplasia type 2 (MEN2). The most common tumors associated with MEN2 are those of the parathyroid, thyroid, and adrenal glands. Additional manifestations include characteristic clinical phenotypes or features as described in the article. This review provides an overview of clinical manifestations, screening, diagnosis, treatment, and surveillance of patients with MEN2.

Prognostic Performance of Alternative Lymph Node Classification Systems for Patients with Medullary Thyroid Cancer: A Single Center Cohort Study

BACKGROUND

Lymph node ratio (LNR) and the log odds of positive lymph nodes (LODDS) have been proposed as alternative lymph node (LN) classification schemes. Various cut-off values have been defined for each system, with the question of the most appropriate for patients with medullary thyroid cancer (MTC) still remaining open. We aimed to retrospectively compare the predictive impact of different LN classification systems and to define the most appropriate set of cut-off values regarding accurate evaluation of overall survival (OS) in patients with MTC.

METHODS

182 patients with MTC who were operated on between 1985 and 2018 were extracted from our medical database. Cox proportional hazards regression models and C-statistics were performed to assess the discriminative power of 28 LNR and 28 LODDS classifications and compare them with the N category according to the 8th edition of the AJCC/UICC TNM classification in terms of discriminative power. Regression models were adjusted for age, sex, T category, focality, and genetic predisposition.

RESULTS

High LNR and LODDS are associated with advanced T categories, distant metastasis, sporadic disease, and male gender. In addition, among 56 alternative LN classifications, only one LNR and one LODDS classification were independently associated with OS, regardless of the presence of metastatic disease. The C-statistic demonstrated comparable results for all classification systems showing no clear superiority over the N category.

CONCLUSION

Two distinct alternative LN classification systems demonstrated a better prognostic performance in MTC patients than the N category. However, larger scale studies are needed to further verify our findings.

Long-Term Outcomes and Causes of Death among Medullary Thyroid Carcinoma Patients with Distant Metastases

Distant metastasis is a poor prognostic factor in medullary thyroid carcinoma (MTC), but the significance of differentiating the characteristics according to the site of distant metastasis remains unclear. This study aimed to evaluate the clinical characteristics and long-term oncologic outcomes in MTC patients with distant metastasis. We identified 46 MTC patients with distant metastasis between 1994 and 2019. Clinical characteristics were compared based on the timing of the detection of distant metastasis. Additionally, survival rates following the detection of distant metastasis were evaluated to compare the clinical significance of metastatic site. The detailed causes of death were also investigated. Of the 46 patients, 15 patients (32.6%) had synchronous distant metastasis and 31 patients (67.4%) had metachronous distant metastasis. There was no clinical difference between these two groups except regarding initial surgical extent. The lung (52.2%) was the most common metastatic site, followed by the bone (28.3%), mediastinum (19.6%), liver (17.4%), adrenal gland (4.3%), brain (4.3%), kidney (2.2%), and pancreas (2.2%). Patients with bone metastasis and multisite metastasis had significantly worse prognoses than those with lung metastasis (hazard ratio: 5.42; p = 0.044 and hazard ratio: 6.11; p = 0.006). Complications due to the progression of distant metastasis, airway obstruction due to tracheal invasion, and complications related to chemotherapy were leading causes of death. In conclusion, there was no difference in clinical characteristics according to the timing of distant metastasis. Oncological outcomes differed by metastatic site.

Similar Stage-dependent Survival and Outcome in Sporadic and Hereditary Medullary Thyroid Carcinoma

CONTEXT

Long-term data are scarce on large cohorts with sporadic (sMTC) and hereditary medullary thyroid carcinoma (hMTC).

OBJECTIVES

To compare long-term disease-specific survival (DSS) and outcomes between sMTC and hMTC groups.

DESIGN

Retrospective analysis.

SETTING

German tertiary referral center.

PATIENTS

A total of 673 patients with MTC that underwent surgery from January 1974 to July 2019.

INTERVENTION

None (observational study).

MAIN OUTCOME MEASURE

Differences between sMTC and hMTC in long-term, stage-dependent survival and outcomes.

RESULTS

Surgery was performed at median ages of 49 years for sMTC (n = 477, 44% male) and 29 years for hMTC (n = 196, 43% male; P < 0.0001). The mean follow-up times were 9.2 ± 8.0 (sMTC) and 14.6 ± 10.3 years (hMTC). Age and tumor stage at diagnosis were significantly different between the 2 groups (P < 0.0001). The sMTC and hMTC groups had different overall DSS (log rank, P = 0.0183), but similar stage-dependent DSS (log rank, P = 0.1242-0.8981). In a multivariate analysis, sMTC and hMTC did not differ in DSS (hazard ratio [HR] = 1.56; 95% CI, 0.94-2.57), but in both groups, a worse DSS was significantly associated with age at diagnosis (HR = 1.04; 95% CI, 1.02-1.05), male sex (HR = 0.49; 95% CI, 0.32-0.76), and stages III and IV at diagnosis (HR = 20.00; 95% CI, 2.74-145.91 and HR = 97.47; 95% CI, 13.07-726.67, respectively). The groups had significantly different (P < 0.0001) outcomes (i.e., cured, minimal residual disease, structural detectable disease, and death), but similar stage-dependent outcomes (P = 0.9449-0.0511), except for stage III (P = 0.0489).

CONCLUSION

Patients with sMTC and hMTC had different ages of onset, but similar stage-dependent DSS and outcomes after the MTC diagnosis. This finding suggested that tumor behavior was similar in sMTC and hMTC.

Reevaluation of the Correlations between Ultrasound Features of Thyroid Nodules and Grades of Bethesda Classification

AIM: To reevaluate the correlations between ultrasound (US) features of thyroid nodules (THNs) and grades of Bethesda classification, to select correctly the patients who must undergo fine needle aspiration (FNAB). MATERIAL AND METHODS: In this study, we have included 260 cytologies of thyroid gland between the period of 2014–2018. The procedures are performed at radiology department of Hygeia Hospital. In our study are excluded the cases with a high risk of hemorrhage and the patients which did not accept the anesthetic procedure because of anxiety. The study includes only the first punctions with their respective Bethesda classification and not repeated FNAB cases. First using the z test, we compared the percentage occupied by the Bethesda categories that are indicative of surgery (BIV + BV + BVI) at US features that suspect malignancy (hypoechogenicity, microcalcifications, abnormal contours, central vascularization), with the percentage occupied by group (BIV + BV + BVI) at the US features which indicate benignity (hyperechoic, no microcalcifications, peripheral vascularization, cystic-solidocystic, spongiform, normal contours). Furthermore, We have evaluated utilizing the odds ratio if there was a correlation between TR4 and TR5 categories in ACR/TIRADS classification and the categories (BIV+BV+BVI) for any statistical significance. The significance of the dimensions of the nodule was tested as an indicator for surgical intervention. For this purpose, the percentage occupied by the nodules with a diameter larger than 1.5 cm at (BIV + BV + BVI) group was compared with the percentage occupied by nodules smaller than 1.5 cm at BIV + BV + BVI. In addition, we observed if there was a strong statistical connection between nodules larger than 1.5 cm and the Bethesda categories that suggested malignancy. There was no statistical test made for the features “taller than wide” and microcalcifications because of the small number of cases. It was also made a comparison of percentages (BIV + BV + BVI) even for three clinical features: Men versus women, solitary nodule versus multinodular goiter, left lobe versus right lobe. We compared the percentages occupied by the (BIV + BV + BVI) group of categories in patients over 45 years old with the percentages occupied by this group at patients younger than 45 years old. We also noted which of Bethesda categories is more frequent. CONCLUSIONS: The features that are more indicative for FNAB are hypoechogenicity, consistency, intranodal vascularization, and extralobar positioning. If a THN has one of the above features and has a dimension of more than 10 mm, it has an indication for FNAB. Indications for FNAB increase with the increasing of the abovementioned features of a THN. The combination of US features that suggest malignancy, TR4 and TR5, with BIII category is a strong indicator for surgical intervention. The results of this study are similar with the results of prior studies, and we could not distinguish any specific US feature that has an absolute indication for FNAB. The appropriate determination of the US features of a THN in correlation with the patient’s clinic information will determine the proper indication for a FNAB.

RET gene mutation analysis and long-term clinical outcomes of medullary thyroid cancer patients

OBJECTIVE

Medullary thyroid carcinoma is a rare, potentially aggressive tumour, with relatively worse prognosis than well-differentiated thyroid cancer. We evaluated the long-term outcomes and prognosis of medullary thyroid carcinoma patients at a single institution in India and compared outcomes based on results of RET protooncogene mutation analysis.

METHODS

Data were retrieved through a prospectively maintained thyroid cancer database from 1998 to June 2019, and medullary thyroid carcinoma patients were recruited. RET gene mutation status (exon 10-16) was assessed. Patient with a minimum follow-up of 12 months was eligible to be part of the long-term outcome analysis.

RESULTS

Out of 149 peripheral blood samples, 42 were positive for RET gene mutation (prevalence of 28.1%). The median follow-up duration was 48 months, ranging from 12 to 240 months. Long-term clinical outcomes of 113 patients were assessed. Two deaths were noted in this series. Both 5- and 10-year survival was cent per cent. Overall survival was 98.2% (97.3% in RET positive and 98.7% in RET negative group). Progression-free survival was 55.4% in total (60% in RET positive and 53.3% in RET negative group). No statistically significant difference was found between RET positive and RET negative groups concerning overall survival (P = 0.6011) and progression-free survival (P = 0.5140). Univariate analysis revealed high calcitonin (>10 pg/mL), stage IV disease, and presence of lymph nodal metastasis to be significant predictors of disease recurrence, however, multivariate analysis demonstrated the presence of lymph node metastases as the only significant predictor of recurrence (P = 0.0005).

CONCLUSIONS

Medullary thyroid carcinoma patients had relatively favourable long-term outcomes. Long-term survival was similar irrespective of RET mutation status. Presence of lymph node metastases appeared to be the strongest predictor of overall and progression-free survival, followed by Calcitonin level and stage of the disease.

Ultrasound of Thyroid Nodules and the Thyroid Imaging Reporting and Data System

Benign or malignant thyroid nodules are common in adults. Fine needle aspiration biopsy is the gold standard for diagnosis. Most thyroid nodules are benign. Ultrasound imaging is the optimal noninvasive imaging modality to determine which nodules demonstrate malignant features. The American College of Radiology Thyroid Imaging Reporting and Data System committee published a standardized approach to classifying nodules on ultrasound. The ultrasound features in this system are categorized as benign, minimally suspicious, moderately suspicious, or highly suspicious for malignancy. Applying the Thyroid Imaging Reporting and Data System results in a meaningful decrease in the number of thyroid nodules biopsied.

Medullary thyroid cancer outcomes in patients with undetectable versus normalized postoperative calcitonin levels

BACKGROUND

Calcitonin (Ct) is a sensitive diagnostic biomarker and one of the most important prognostic factors in medullary thyroid cancer (MTC). This study aimed to evaluate progression-free survival and recurrence rates of MTC associated with undetectable compared with normalized serum Ct levels after surgery.

METHODS

This retrospective observational study included patients operated for MTC at the Digestive and Endocrine Surgery Department of Lyon Sud Hospital Centre between 2000 and 2019. Clinical and pathological factors were correlated with postoperative Ct concentrations. Undetectable and normalized Ct concentrations were defined as below 2 pg/ml and 2-10 pg/ml respectively.

RESULTS

Overall, 176 patients were treated for MTC, and 127 were considered biochemically cured after surgery. Of these, 24 and 103 had normalized and undetectable Ct concentrations respectively. Patients with Ct level normalization had a 25 per cent risk of disease recurrence, compared with 3 per cent in patients with undetectable Ct levels after surgery. The presence of metastasis in two or more compartments was predictive of failure to achieve undetectable Ct concentrations after surgery and an increased risk of recurrence.

CONCLUSION

Among patients with biochemically cured MTC, those with undetectable or normalized Ct concentrations after surgery had different risks of recurrence. Simply assessing postoperative Ct normalization can be falsely reassuring, and long-term follow-up is needed.

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.

Predicting Outcomes in Sporadic and Hereditary Medullary Thyroid Carcinoma over Two Decades

Background: Medullary thyroid cancer (MTC) can be associated with significant morbidity and mortality in advanced cases. Hence, we aimed to identify factors at the time of MTC surgery that predict overall survival (OS), disease-specific survival (DSS), locoregional recurrence/persistence (LR), and distant metastases (DM). Methods: We performed a retrospective study of clinicopathologic, radiological, and laboratory data in MTC patients who underwent thyroidectomy at Mayo Clinic from January 1995 to December 2015. Results: We identified 163 patients (mean age 48.4 years, 48% males), 102 with sporadic MTC and 61 with hereditary disease (n = 46 multiple endocrine neoplasia [MEN] 2A, n = 3 MEN 2B, n = 12 familial MTC) with a median follow-up time of 5.5 years. On univariate analysis, age >55 years, male sex, DM at the time of surgery (M1), lateral neck lymph node (LN) involvement (N1b), gross extrathyroidal extension (ETE), American Joint Committee on Cancer (AJCC) stage 3/4, tumor size (T) 3/4, tumor size, and postoperative calcitonin (Ctn) and carcinoembryonic antigen (CEA) were significant predictors of worse OS and DSS. On multivariable analysis, both gross ETE (hazard ratio [HR] 4.62, 6.58) and M1 (HR 5.11, 10.45) remained significant predictors of worse OS as well as DSS, while age >55 years (HR 3.21), male sex (HR 2.42), and postoperative Ctn (HR 1.002 for every 100 pg/mL increase) were significant only for worse OS. On univariate analysis, male sex, M1, N1b, gross ETE, stage 3/4, T 3/4, tumor size, number of LNs involved, and postoperative Ctn were significant predictors of LR and DM; age >55 years was additionally significant for DM. On multivariable analysis, gross ETE (HR 3.16, 5.93) and N1b (HR 4.31, 4.64) remained significant predictors of LR and DM; ratio of resected/involved LN (HR 10.91) was additionally predictive for LR and postoperative Ctn (HR 1.003 for every 100 pg/mL increase) for DM. Conclusions: Disease burden at initial surgery, especially gross ETE, lateral neck LN involvement, and DM, as well as the biochemical response to surgery appear to be more important than demographic factors in terms of MTC prognosis. These findings highlight the importance of rigorous perioperative assessment to better predict MTC outcomes.

Comprehensive Immune Profiling of Medullary Thyroid Cancer

Background: Despite advances in targeted kinase inhibitor development for patients with medullary thyroid cancer (MTC), most patients develop resistance and would benefit from alternative approaches. Immune-based therapies are now considered for patients with progressive MTC. This study is the first comprehensive assessment of the immune milieu, immune-suppressive molecules, and potential tumor antigens in patients with MTC. Methods: Primary and/or regionally metastatic tumor tissues from 46 patients with MTC were screened for immune infiltrates by using standard immunohistochemistry (IHC) and further analyzed by multispectral imaging for T cell and myeloid markers. RNASeq expression profiling was performed in parallel. RNASeq, targeted sequencing, and IHC techniques identified cancer-associated mutations and MTC-enriched proteins. Results: Organized immune infiltration was observed in 49% and 90% of primary and metastatic tumors, respectively. CD8⁺ cells were the dominant T cell subtype in most samples, while CD163⁺ macrophages were most frequent among myeloid infiltrates. PD-1⁺ T cells were evident in 24% of patients. Myeloid subsets were largely major histocompatibility complex II (MHCII^-), suggesting a dysfunctional phenotype. Expression profiling confirmed enrichment in T cell, macrophage, and inflammatory profiles in a subset of samples. PD-L1 was expressed at low levels in a small subset of patients, while the immune regulatory molecules CD155 and CD47 were broadly expressed. Calcitonin, GRP, HIST1H4E, NOMO3, and NPIPA2 were highly and specifically expressed in MTC. Mutations in tumor suppressors, PTEN and p53, and mismatch repair genes, MSH2 and MSH6, may be relevant to disease progression and antigenicity. Conclusions: This study suggests that MTC is a more immunologically active tumor that has been previously reported. Patients with advanced MTC should be screened for targetable antigens and immune checkpoints to determine their eligibility for current clinical trials. Additional studies are necessary to fully characterize the antigenic potential of MTC and may encourage the development of adoptive T cells therapies for this rare tumor.

High Ratio of Early Postoperative Calcitonin to Preoperative Calcitonin Could be a Novel Indicator of Poor Prognosis in Patients with Biochemical Incomplete Responses in Sporadic Medullary Thyroid Cancer

OBJECTIVE

In a cohort of medullary thyroid cancer (MTC) patients with biochemical incomplete responses, 37 to 48% developed structural persistent disease; however, few indictors were available to distinguish those patients who were more likely to develop structural disease. We hypothesized that the relationship between preoperative calcitonin (Ctn) and postoperative Ctn (within 3 days after surgery) could be used to predict early prognosis of these patients.

METHODS

A total of 92 sporadic MTC patients were enrolled in this study. Our team proposed a novel indicator of structural persistent MTC called the calcitonin ratio (CR; CR = postoperative Ctn/preoperative Ctn). Cox regression models and the Kaplan-Meier method were used to evaluate the prognostic capability of CR. The area under the time-dependent receiver-operating characteristic curves (AUC) and the Harrell concordance index (C-index) were used for analysis.

RESULTS

The cutoff CR value used to determine MTC prognosis was 0.15. Multivariate Cox analysis revealed that CR (hazard ratio [HR]: 22.974, 95% confidence interval [CI]: 3.259 to 161.959, P = .002), tumor-node-metastasis (HR: 3.968, 95% CI: 1.360 to 21.857; P = .031), and multifocality (HR: 8.466, 95% CI: 1.286 to 55.716; P = .026) independently correlated with MTC prognosis. Kaplan-Meier survival curves demonstrated a lower proportion with structural persistent disease in patients with CR <0.15 (P<.001). The 3, 5, and 10-year AUC values were 0.798, 0.752, and 0.743, respectively. The C-index of CR was 0.788 (95% CI: 0.763 to 0.813).

CONCLUSION

In this study, CR was identified as a sensitive and specific risk stratification marker for patients with biochemical incomplete responses in sporadic MTC.

ABBREVIATIONS

ATA = American Thyroid Association; AUC = area under curve; CEA = carcinoembryonic antigen; CR = calcitonin ratio; Ctn = calcitonin; HR = hazard ratio; MTC = medullary thyroid cancer; ROC = receiver operating characteristic; TNM = tumor-node-metastasis.

Modern surgery for advanced thyroid cancer: a tailored approach

Surgical treatment of advanced thyroid malignancy can be morbid, compromising normal functions of the upper aerodigestive tract. There is a paucity of guidelines dedicated to the management of advanced disease. In fact, there is not even a uniform definition for advanced thyroid cancer currently. The presence of local invasion, bulky cervical nodes, distant metastases or recurrent disease should prompt careful preoperative evaluation and planning. Surgical strategy should evolve from multidisciplinary discussion that integrates individual disease characteristics and patient preference. Intraoperative neuromonitoring has important applications in surgery for advanced disease and should be used to guide surgical strategy and intraoperative decision-making. Recent paradigm shifts, including staged surgery and use of neoadjuvant targeted therapy hold potential for decreasing surgical morbidity and improving clinical outcomes. Modern surgical planning provides optimal treatment for each patient through a tailored approach based on exact extent and type of disease as well as incorporating appreciation of surgical complications, patient preferences and intraoperative findings.

Clinico-pathologic and dynamic prognostic factors in sporadic and familial medullary thyroid carcinoma: an Israeli multi-center study

OBJECTIVE

Multiple clinical, pathological and biochemical variables, including the response to initial treatment, are associated with medullary thyroid carcinoma (MTC) prognosis. Studies that include separate analyses of familial and sporadic MTC patients followed for long period are scarce. This study evaluated the association between baseline clinico-pathologic variables and response to initial treatment and short- and long-term disease outcomes in sporadic and familial MTC.

METHODS

Patients treated for MTC at four tertiary medical centers were retrospectively analyzed. Clinical and pathological data were collected. The outcomes measured included disease persistence 1 year after diagnosis, disease persistence at last follow-up, disease-related mortality (DRM) and all-cause mortality.

RESULTS

The study enrolled 193 patients (mean age: 48.9 ± 18.7, 44.7% males), of whom 18.1% were familial cases. The mean follow-up period was 10.1 ± 9.4 years (8.5 ± 8.1 in sporadic and 16.9 ± 11.6 in familial MTC). Disease persistence 1-year after diagnosis and at last follow-up was detected in 56.1 and 60.4% patients, respectively. All-cause and DRM were 28.5 and 12.6%, respectively. Extra-thyroidal extension (ETE) and distant metastases (DM) were associated with disease persistence at last follow-up. ETE and DM were also significantly associated with DRM. Complete remission 1 year after diagnosis had high correlation with no evidence of disease at last follow-up (Cramer's V measure of association 0.884, P < 0.001) and with 100% disease-specific survival (Cramer's V measure of association 0.38, P < 0.001).

CONCLUSIONS

Apart from clinico-pathologic parameters, close correlation was found between 1-year status and long-term prognosis. These results underscore the importance of combining classical and dynamic factors for both sporadic and familial MTC prognostication and treatment decision making.

Static Prognostic Factors and Appropriate Surgical Designs for Patients with Medullary Thyroid Carcinoma: The Second Report from a Single-Institution Study in Japan

Background

Medullary thyroid carcinoma (MTC) originates from calcitonin-producing cells of the thyroid. In 2009, we published our first report on the biological characteristics and prognosis of 118 MTC patients. Herein, we enrolled a larger number of patients with longer follow-up periods to further study the biological characteristics and appropriate therapies for MTC.

Methods

In general, hemithyroidectomy and total thyroidectomy were performed for sporadic MTC confined to the thyroid lobe and for hereditary MTC with central node dissection, respectively. Moreover, prophylactic modified radical neck dissection was performed on the side of macroscopic tumors.

Results

In total, 233 patients (99 hereditary and 134 sporadic) were enrolled. The median follow-up time was 128 months (range 7–445 months). Biochemical cure was obtained in 36 (62%) of the 58 patients who underwent prophylactic MND and were pathologically positive for lateral node metastasis. None of the patients had recurrence in the preserved thyroid. Distant recurrence was detected in 19 patients, and 12 died of MTC. Preoperative calcitonin and carcinoembryonic antigen levels, tumor size (T) > 4 cm, the male sex, clinical and pathological node metastases (N1), distant metastasis (M1), extrathyroid extension (Ex), and a lack of biochemical cure had prognostic impacts on distant recurrence and/or carcinoma-related mortality on univariate analysis. On multivariate analysis, Ex was independently correlated with distant recurrence, and Ex, T > 4 cm, and M1 independently affected carcinoma-related mortality.

Conclusion

MTC patients had excellent prognosis in our institutions, indicating that our surgical strategies were appropriate.

Different outcomes in sporadic versus familial medullary thyroid cancer

BACKGROUND

Medullary thyroid carcinoma (MTC) has varying clinical course with familial cases (fMTC) diagnosed earlier than sporadic MTC (spMTC).

METHODS

A total of 273 MTCs (familial: n = 110 [40.3%], males: 38.5%) were followed for 1-35 years (median 5.0 years). Fifty one of the familial cases were operated because of positive findings at genetic screening. Disease extent at diagnosis and follow-up was recorded.

RESULTS

Mean age at diagnosis was: fMTC = 33.85 ± 16.5 years (range 4-74) and spMTC = 52.6 ± 14.0 years (range 16-81, P < .001). This difference remained when genetic screening cases were excluded. fMTCs had more frequently multifocality, smaller size, and more favorable stage at diagnosis (stages I and II: 60.9% vs 47.9%, stage III: 30.0% vs 23.9%, stage IV: 9.1% vs 28.9%, P = .01). fMTC had lower preoperative and postoperative calcitonin, more frequently remission (59.1% vs 47.2%) and less frequently progressive disease (8.2% vs 35.0%, P < .001). After excluding genetic screening cases, no difference in stage at diagnosis was observed. Outcome was more favorable in fMTC compared to sporadic (P = .002); the 10-year probability of lack of progression of disease differed significantly between fMTCs and spMTCs (86.4% vs 65.0%, P < .001).

CONCLUSION

After excluding genetic screening cases, although stage at diagnosis is similar, disease outcome remains worse in sporadic compared to fMTCs.

Postoperative Neck Ultrasonography Surveillance After Thyroidectomy in Patients With Medullary Thyroid Carcinoma: A Multicenter Study

BACKGROUND

For detecting tumor recurrence of medullary thyroid carcinoma (MTC) in the neck, an appropriate frequency and interval of postoperative ultrasonography (US) surveillance remains unclear. This study aimed to assess an appropriate interval and frequency of postoperative neck US surveillance for detecting tumor recurrence in patients who had undergone thyroid surgery due to MTC.

METHODS

A total of 86 patients who had undergone thyroid surgery for the treatment of MTC and had at least one postoperative US follow-up examination at any of nine affiliated hospitals were included. Postoperative follow-up US, clinical, and histopathological results of patients were reviewed. The tumor recurrence/persistence rate of MTC was investigated, and the interval and session number of postoperative follow-up US and clinicopathologic factors were compared between tumor recurrence/persistence and non-recurrence groups.

RESULTS

Of the 86 patients, 22 (25.6%) showed tumor recurrence/persistence. Of the 22 patients with tumor recurrence/persistence, 11 (50%) showed structural recurrence/persistence in the neck on follow-up US. In these 11 patients, the mean interval and session number of postoperative follow-up US between initial surgery and the first US detection of recurrence/persistence was 41.3 ± 39.3 months (range, 6-128 months) and 2.6 ± 2.3 (range, 1-8), respectively. On follow-up US, 6 (54.5%, 6/11) were diagnosed with tumor recurrence/persistence within 3 years of the initial surgery. Tumor recurrence/persistence was significantly correlated with TNM stage (p < 0.001) and multiplicity/bilaterality (p = 0.013).

CONCLUSION

For detecting MTC recurrence/persistence, postoperative US surveillance at 1-year intervals may be sufficient within the first 3 years after thyroid surgery, but depending on the presence of relevant risk factors, annual or biannual US surveillance may be recommendable for 4-10 years after thyroid surgery.

Long-Term Survivorship in Multiple Endocrine Neoplasia Type 2B Diagnosed Before and in the New Millennium

CONTEXT

Recent long-term outcomes and survival data are lacking for patients with multiple endocrine neoplasia type 2B (MEN2B).

OBJECTIVES

To analyze long-term MEN2B outcomes and define prognostic factors.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective comparative study of 75 patients with MEN2B from two German tertiary referral centers. Patients diagnosed and treated before and after 2000 were compared for demographic, biochemical, surgical, and outcome parameters.

INTERVENTION

Surgery.

MAIN OUTCOME MEASURE

Long-term survival.

RESULTS

We identified seven familial and 68 de novo cases of MEN2B; 61 exhibited the RET M918T genotype (2 others exhibited A883F and E768D/L790T mutations). Surgery was performed at a mean age of 16.4 ± 11.2 years. The tumor stages at diagnosis for 71 patients were stage I, 15%; stage II, 6%; stage III, 35%; and stage IV, 44%. The mean follow-up was 9.6 ± 9.0 years. The outcomes were 15 (20%) cured, 9 (12%) with minimal residual disease, 19 (25%) with metastatic disease, and 10 (13%) unknown. Medullary thyroid cancer (MTC) caused 22 deaths (29%) 7.3 ± 6.2 years after diagnosis (mean age, 22.9 ± 10.7 years). The overall survival rates at 5, 10, and 20 years were 85%, 74%, and 58%, respectively. After 2000 (vs before 2000), significantly more patients had stage I and II (32% vs 11%) and more were cured (43% vs 20%), with a higher survival trend (P = 0.058). The only prognostic factor was tumor stage at diagnosis.

CONCLUSIONS

Patients with MEN2B developed MTC at an early age with wide ranging aggressiveness, but the outcome was generally better after 2000 than before 2000.

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.

Prognostic Significance of Circulating RET M918T Mutated Tumor DNA in Patients With Advanced Medullary Thyroid Carcinoma

CONTEXT

Interpretation of calcitonin measurement to predict the prognosis of medullary thyroid carcinoma (MTC) requires multiple measurements over an extended time period, making it an imperfect biomarker for evaluating prognosis or disease behavior. Single circulating cell-free DNA (cfDNA) values have been shown to be a valuable prognostic marker for several solid tumors.

OBJECTIVE

We tested the hypothesis that cfDNA containing the RET M918T mutation could be detected in the blood of patients with advanced MTC whose tumor harbored an M918T mutation and would be able to predict overall survival more reliably than calcitonin.

DESIGN

The level of cfDNA containing RET M918T mutation was measured in the plasma of patients with MTC via droplet digital polymerase chain reaction.

PATIENTS

Patients had a confirmed sporadic MTC diagnosis, a serum calcitonin measurement >100 pg/mL, and tumor tissue biopsy results providing RET M918T mutation status. There were 75 patients included in this study, 50 of whom harbored an RET M918T mutation by tissue biopsy.

RESULTS

RET M918T cfDNA was detected in 16 of 50 patients (32%) with a positive tissue biopsy. The detection of RET M918T cfDNA strongly correlated with worse overall survival and more accurately predicted a worse outcome than calcitonin doubling time.

CONCLUSIONS

Liquid biopsy is able to detect RET M918T mutations in patient plasma with high specificity but low sensitivity. In patients with established somatic RET M918T mutations, the allelic fraction of circulating tumor DNA is prognostic for overall survival and may play a role in monitoring response to treatment.

PROGNOSTIC VARIABLES AFFECTING PRIMARY TREATMENT OUTCOME FOR MEDULLARY THYROID CANCER

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

ABBREVIATIONS

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

Systemic treatment and management approaches for medullary thyroid cancer

Although rare, medullary thyroid cancer (MTC) exemplifies the value that ever-expanding knowledge of molecular pathways and mechanisms brings to managing challenging cancers. Although surgery can be curative for MTC in many patients, a substantial proportion of patients present with locoregional or distant metastatic disease. Once distant disease occurs, treatment options are limited, and conventional cancer treatments such as cytotoxic chemotherapy are of minimal benefit. Biomarkers such as calcitonin and carcinoembryonic antigen are important correlates of disease burden as well as predictors of disease progress, including recurrence and survival. MTC is either sporadic (∼75%) or inherited (∼25%) as an autosomal dominant disease. Regardless, germline and somatic mutations, particularly in the rearranged during transfection (RET) proto-oncogene, are key factors in the neoplastic process. Gain-of-function RET mutations result in overactive proteins that lead to abnormal activation of downstream signal transduction pathways, resulting in ligand-independent growth and resistance to apoptotic stimuli. Specific RET mutation variants have been found to correlate with phenotype and natural history of MTC with some defects portending a more aggressive clinical course. Greater understanding of the consequence of the aberrant signaling pathway has fostered the development of targeted therapies. Two small-molecule tyrosine kinase inhibitors, vandetanib and cabozantinib, are currently available as approved agents for the treatment of advanced or progressive MTC and provide significant increases in progression-free survival. Since there have been no head-to-head comparisons, clinicians often select between these agents on the basis of familiarity, patient characteristics, comorbidities, and toxicity profile.

Retrospective analysis of 140 cases of medullary thyroid carcinoma followed-up in a single institution

Familial cases of medullary thyroid carcinoma (MTC) may be diagnosed by genetic screening, while in sporadic tumors the diagnosis relies mainly on fine-needle aspiration cytology. The aim of the present study was to determine the demographic, clinical and pathological characteristics of MTC patients followed-up at the Portuguese Institute of Oncology Francisco Gentil (Lisbon, Portugal). For that purpose, a retrospective analysis of 140 MTC patients diagnosed between 1990 and 2010 was performed. The results indicated that patients with hereditary MTC (11.4%) were significantly younger than patients with sporadic MTC. Of the latter, 34.3% had no clinical suspicion of MTC prior to surgery. The sensitivity of cytology and calcitonin (CT) assay in diagnosing MTC were 51.3 and 98.7%, respectively. All familial index cases and 69.0% of sporadic cases presented with advanced stage disease at the time of diagnosis, while 73.0% of familial MTC detected by genetic/pentagastrin screening were diagnosed at the early stage of the disease. Biochemical cure (BC) was achieved in 39.7% of patients and, of these, only 6.5% relapsed. The 5 and 10-year survival rates were 79.3 and 73.6%, respectively. Age >45 years (P=0.026), advanced stage at diagnosis (P<0.001) and absence of BC (P<0.001) were predictors of a worse prognosis on univariate analysis. However, when the patients detected by genetic/pentagastrin screening were excluded from the analysis, age was no longer a prognostic factor, although disease stage remained a significant prognostic factor. On multivariate analysis, BC was the only factor with a significant impact on prognosis (P=0.031). In addition, the present study confirmed that the majority of patients were diagnosed at advanced stages, and CT determination was observed to be more sensitive than cytology to diagnose MTC. Patients at early stages were more prone to achieve BC, which was a favorable prognostic factor. To the best of our knowledge, the present study reports for the first time that age at diagnosis is not a predictor of survival for patients with MTC when cases diagnosed by genetic/pentagastrin screening (who are usually young patients at the initial stages of the disease), are excluded from the analysis.

Postoperative biochemical remission of serum calcitonin is the best predictive factor for recurrence-free survival of medullary thyroid cancer: a large-scale retrospective analysis over 30 years

CONTEXT

The increase in thyroid screening in the general population may lead to earlier detection of medullary thyroid carcinoma (MTC).

OBJECTIVE

We aimed to evaluate secular trends in clinicopathological characteristics and long-term prognosis of MTC and its prognostic factors.

DESIGN

This was a retrospective analysis from 1982 to 2012.

PATIENTS

Three hundred and thirty-one patients with MTC were included and grouped based on the year of diagnosis (1982-2000, 2001-2005, 2006-2010 and 2011-2012).

MEASUREMENTS

These included recurrence and mortality as well as biochemical remission (BCR) of serum calcitonin.

RESULTS

Mean tumour size (from 2·5 cm to 1·7 cm, P < 0·001) and percentage of extrathyroidal extension (from 52·0% to 26·0%, P = 0·026) decreased. The percentage of patients achieving BCR within six postoperative months (po-BCR) increased with time (from 39·6% to 76·1%, P < 0·001). The 5-year overall recurrence rate significantly decreased in 2006-2012 compared to 1982-2005 (10% vs 18%, respectively, P = 0·031), although the 5-year survival rate did not improve (92% vs 92%, P = 0·929). Failure to achieve po-BCR was the strongest predictive factor associated with recurrence (hazard ratio [HR] = 58·04, 95% CI 7·14-472·11; P < 0·001). Male gender (HR = 3·18, 95% CI 1·18-8·56; P = 0·022), tumour size >2 cm (HR = 18·33, 95% CI 2·35-143·06; P = 0·006) and distant metastasis (HR = 4·00, 95% CI 1·31-12·21; P = 0·015) were significant prognostic factors for mortality.

CONCLUSIONS

Clinicopathological characteristics and recurrence of MTC improved with time. Po-BCR was the best predictive factor for recurrence-free survival.

Recurrent spinal metastasis of a sporadic medullary carcinoma of the thyroid after radiation therapy: a case report and review of the literature

Sporadic Medullary Carcinoma of the Thyroid is a relatively uncommon entity and at the time of diagnosis, most already present loco-regional metastasis. Therapy should be aggressive to reduce recurrence and mortality. Follow-up period should continue lifelong and should also include calcium/pentagastrin infusion test, as well as 6-month interval diagnostic imaging.

Revised American Thyroid Association guidelines for the management of medullary thyroid carcinoma

INTRODUCTION

The American Thyroid Association appointed a Task Force of experts to revise the original Medullary Thyroid Carcinoma: Management Guidelines of the American Thyroid Association.

METHODS

The Task Force identified relevant articles using a systematic PubMed search, supplemented with additional published materials, and then created evidence-based recommendations, which were set in categories using criteria adapted from the United States Preventive Services Task Force Agency for Healthcare Research and Quality. The original guidelines provided abundant source material and an excellent organizational structure that served as the basis for the current revised document.

RESULTS

The revised guidelines are focused primarily on the diagnosis and treatment of patients with sporadic medullary thyroid carcinoma (MTC) and hereditary MTC.

CONCLUSIONS

The Task Force developed 67 evidence-based recommendations to assist clinicians in the care of patients with MTC. The Task Force considers the recommendations to represent current, rational, and optimal medical practice.

The thyroid: review of imaging features and biopsy techniques with radiologic-pathologic correlation

Knowledge of the normal and abnormal imaging appearances of the thyroid gland is essential for appropriate identification and diagnosis of thyroid lesions. Thyroid nodules are often detected incidentally at computed tomography, magnetic resonance imaging, and positron emission tomography; however, ultrasonography (US) is the most commonly used imaging modality for characterization of these nodules. US characteristics that increase the likelihood of malignancy in a thyroid nodule include microcalcifications, solid composition, and central vascularity. Nuclear scintigraphy is commonly used for evaluation of physiologic thyroid function and for identification of metabolically active and inactive nodules. When fine-needle aspiration biopsy (FNAB) of a lesion is indicated based on clinical and radiologic features, appropriate US-guided biopsy technique and careful cytologic analysis are crucial for making the diagnosis. FNAB and core biopsy are the two percutaneous techniques used to obtain a specimen, with the latter technique being indicated following nondiagnostic or indeterminate FNAB. Specimen adequacy and diagnostic accuracy vary due to several factors, including location of aspiration and biopsy technique used. The radiologist must have a basic knowledge of thyroid disease, be familiar with specimen processing, and recognize the cytologic and radiologic appearances of thyroid lesions, all of which will facilitate the management of these lesions. Online supplemental material is available for this article.

Long-Term Follow-up in Medullary Thyroid Carcinoma

After surgery, patients with medullary thyroid carcinoma (MTC) should be assessed regarding the presence of residual disease, the localization of metastases, and the identification of progressive disease. Postoperatively, patients with MTC are staged to separate those at low risk from those at high risk of recurrence. The TNM staging system is based on tumor size, extra-thyroidal invasion, nodal metastasis, and distant spread of cancer. In addition, the number of lymph-node metastases, the number of compartments involved, and the postoperative calcitonin (CTN) and carcinoembryonic antigen (CEA) levels should be documented. The postoperative normalization of the serum CTN level is associated with a favorable outcome. When patients have basal serum CTN levels less than 150 pg/ml after a thyroidectomy, any persistent or recurrent disease is nearly always confined to lymph nodes in the neck. When the postoperative serum CTN level exceeds 150 pg/ml, patients should be evaluated with imaging procedures, including computed tomography (CT) of the neck and chest, contrast-enhanced magnetic resonance imaging (MRI) and ultrasound (US) of the liver, bone scintigraphy, MRI of the bone, and positron emission tomography (PET)/CT. One can estimate the growth rate of MTC metastases by quantifying increases in tumor size over time from sequential imaging studies analyzed with response evaluation criteria in solid tumors (RECIST), and by determining the tumor marker doubling time from sequential measures of serum CTN or CEA levels over multiple time points. One of the main challenges remains to find effective adjuvant and palliative options for patients with metastatic disease. Patients with persistent or recurrent MTC localized to the neck following thyroidectomy are candidates for neck operations, depending on the tumor extension. Once metastases appear, the clinician must decide which patients require therapy. This requires a balance between the (often) slow rate of tumor progression, which is associated with a good quality of life, and the limited efficacy and potential toxicities of local and systemic therapies. Considering that metastatic MTC is incurable, the management goals are to provide loco-regional disease control, palliate symptoms of hormonal excess, such as diarrhea, palliate symptomatic metastases, like pain or bone fracture, and control metastases that threaten life, such as bronchial obstruction or spinal cord compression. This can be achieved with palliative surgery, external beam radiation therapy (EBRT), or systemic therapy with tyrosine kinase inhibitor (TKI).

Postoperative Nomogram for Predicting Cancer-Specific Mortality in Medullary Thyroid Cancer

BACKGROUND

Medullary thyroid cancer (MTC) is a rare thyroid cancer accounting for 5 % of all thyroid malignancies. The purpose of our study was to design a predictive nomogram for cancer-specific mortality (CSM) utilizing clinical, pathological, and biochemical variables in patients with MTC.

METHODS

MTC patients managed entirely at Memorial Sloan-Kettering Cancer Center between 1986 and 2010 were identified. Patient, tumor, and treatment characteristics were recorded, and variables predictive of CSM were identified by univariable analyses. A multivariable competing risk model was then built to predict the 10-year cancer specific mortality of MTC. All predictors of interest were added in the starting full model before selection, including age, gender, pre- and postoperative serum calcitonin, pre- and postoperative CEA, RET mutation status, perivascular invasion, margin status, pathologic T status, pathologic N status, and M status. Stepdown method was used in model selection to choose predictive variables.

RESULTS

Of 249 MTC patients, 22.5 % (56/249) died from MTC, whereas 6.4 % (16/249) died secondary to other causes. Mean follow-up period was 87 ± 67 months. The seven variables with the highest predictive accuracy for cancer specific mortality included age, gender, postoperative calcitonin, perivascular invasion, pathologic T status, pathologic N status, and M status. These variables were used to create the final nomogram. Discrimination from the final nomogram was measured at 0.77 with appropriate calibration.

CONCLUSIONS

We describe the first nomogram that estimates cause-specific mortality in individual patients with MTC. This predictive nomogram will facilitate patient counseling in terms of prognosis and subsequent clinical follow up.

Diagnóstico, tratamento e seguimento do carcinoma medular de tireoide: recomendações do Departamento de Tireoide da Sociedade Brasileira de Endocrinologia e Metabologia

Introdução O carcinoma medular de tireoide (CMT) origina-se das células parafoliculares da tireoide e corresponde a 3-4% das neoplasias malignas da glândula. Aproximadamente 25% dos casos de CMT são hereditários e decorrentes de mutações ativadoras no proto-oncogene RET (REarranged during Transfection). O CMT é uma neoplasia de curso indolente, com taxas de sobrevida dependentes do estádio tumoral ao diagnóstico. Este artigo descreve diretrizes baseadas em evidências clínicas para o diagnóstico, tratamento e seguimento do CMT. Objetivo O presente consenso, elaborado por especialistas brasileiros e patrocinado pelo Departamento de Tireoide da Sociedade Brasileira de Endocrinologia e Metabologia, visa abordar o diagnóstico, tratamento e seguimento dos pacientes com CMT, de acordo com as evidências mais recentes da literatura. Materiais e métodos: Após estruturação das questões clínicas, foi realizada busca das evidências disponíveis na literatura, inicialmente na base de dados do MedLine-PubMed e posteriormente nas bases Embase e SciELO – Lilacs. A força das evidências, avaliada pelo sistema de classificação de Oxford, foi estabelecida a partir do desenho de estudo utilizado, considerando-se a melhor evidência disponível para cada questão. Resultados Foram definidas 11 questões sobre o diagnóstico, 8 sobre o tratamento cirúrgico e 13 questões abordando o seguimento do CMT, totalizando 32 recomendações. Como um todo, o artigo aborda o diagnóstico clínico e molecular, o tratamento cirúrgico inicial, o manejo pós-operatório e as opções terapêuticas para a doença metastática. Conclusões O diagnóstico de CMT deve ser suspeitado na presença de nódulo tireoidiano e história familiar de CMT e/ou associação com feocromocitoma, hiperparatireoidismo e/ou fenótipo sindrômico característico, como ganglioneuromatose e habitus marfanoides. A punção aspirativa por agulha fina do nódulo, a dosagem de calcitonina sérica e o exame anatomopatológico podem contribuir na confirmação do diagnóstico. A cirurgia é o único tratamento que oferece a possibilidade de cura. As opções de tratamento da doença metastática ainda são limitadas e restritas ao controle da doença. Uma avaliação pós-cirúrgica criteriosa para a identificação de doença residual ou recorrente é fundamental para definir o seguimento e a conduta terapêutica subsequente.

Biochemical cure after reoperations for medullary thyroid carcinoma: a meta-analysis

BACKGROUND

Despite meticulous surgical techniques, calcitonin levels remain detectable in 40 % to 66 % of patients after initial surgery for medullary thyroid carcinoma (MTC), and the optimal surgical management for persistent or recurrent disease remains controversial. Previous studies suggest that biochemical cure, defined by normalization of postoperative calcitonin measurements, predicts disease-free survival. Reoperative approaches range from targeted removal of detectable disease to comprehensive compartment-oriented lymph node clearance.

METHODS

A proportional meta-analysis of clinical case series of postoperative calcitonin clearance after reoperation for MTC was performed. Studies were obtained from PubMed, Embase, Scopus, and the Cochrane Library.

RESULTS

Twenty-seven articles capturing data of 984 patients met the inclusion criteria for the meta-analysis. Overall, normalization of calcitonin after reoperation for MTC occurred in 16.2 % of patients [95 % confidence interval (CI) 14.0-18.5]. Stratified by operative procedure, targeted selective lymph node removal procedures had a normalization of calcitonin in 10.5 % of patients (95 % CI 6.4-14.7), while compartment-oriented procedures had a higher rate of normalization at 18.6 % (95 % CI 15.9-21.3).

CONCLUSIONS

The rate of calcitonin normalization after reoperation for MTC is enhanced through use of a meticulous compartment-oriented lymph node dissection. Compartment-oriented lymph node dissection results in calcitonin normalization in 18.6 % of reoperative MTC patients and is the procedure of choice in patients in whom the goal is biochemical cure.

Update on medullary thyroid cancer

Medullary thyroid carcinoma (MTC) is a rare type of thyroid cancer, demonstrating variable behavior from indolent disease to highly aggressive, progressive disease. There are distinguishing phenotypic features of sporadic and hereditary MTC. Activation or overexpression of cell surface receptors and up-regulation of intracellular signaling pathways in hereditary and sporadic MTC are involved in the disease pathogenesis. There has been an exponential rise in clinical trials with investigational agents, leading to approval of 2 medications for progressive, advanced MTC. Developments in understanding the pathogenesis of MTC will hopefully lead to more effective and less toxic treatments of this rare but difficult to treat cancer.

Reduced life expectancy seen in hereditary diseases which predispose to early-onset tumors

There are several hereditary diseases that are a predisposition to early-onset tumors. These include syndromic conditions like neurofibromatosis 1 and 2, von Hippel-Lindau syndrome, Gorlin syndrome, multiple endocrine neoplasia, and familial adenomatous polyposis; and conditions which are usually not possible to diagnose clinically in a single individual, such as Lynch syndrome and BRCA1/2. Understanding of the mortality in hereditary cancer predisposing diseases is important for developing effective disease treatment programs. A number of studies have been undertaken to investigate the genetic predictors, prevalence and incidence, and treatment outcomes of these diseases; however, the majority examine only the most common of these diseases (eg, neurofibromatosis or BRCA), or look into postoperative survival. The mortality of individuals who are diagnosed with one of these hereditary diseases remains an area for investigation. This review is the first to attempt identification of studies investigating life expectancy in hereditary diseases which predispose to early-onset tumors.

Radioactive iodine in the treatment of medullary thyroid carcinoma: a controlled multicenter study

OBJECTIVE

Radioactive iodine (RAI) therapy in medullary thyroid carcinoma (MTC) is applied in some centers, based on the assumption that cross-irradiation from thyroid follicular cells may be beneficial. However, no systematic studies on the effect of RAI treatment in MTC have been performed. The aim of this study was to analyze the effect of RAI treatment on survival in MTC patients.

DESIGN

Retrospective multicenter study in eight University Medical Centers in The Netherlands.

METHODS

Two hundred and ninety three MTC patients without distant metastases who had undergone a total thyroidectomy were included between 1980 and 2007. Patients were stratified by clinical appearance, hereditary stage, screening status, and localization. All patients underwent regular surgical treatment with additional RAI treatment in 61 patients. Main outcome measures were disease-free survival (DFS) and disease-specific survival (DSS). Cure was defined as biochemical and radiological absence of disease.

RESULTS

In multivariate analysis, stratification according to clinical appearance (P=0.72), hereditary stage (P=0.96), localization (P=0.69), and screening status (P=0.31) revealed no significant effects of RAI treatment on DFS. Multivariate analysis showed no significant difference in DSS for the two groups stratified according to clinical appearance (P=0.14). Owing to limited number of events, multivariate analysis was not possible for DSS in the other groups of stratification.

CONCLUSIONS

Based on the results of the present analysis, we conclude that RAI has no place in the treatment of MTC.

German Association of Endocrine Surgeons practice guideline for the surgical management of malignant thyroid tumors

INTRODUCTION

Over the past years, the incidence of thyroid cancer has surged not only in Germany but also in other countries of the Western hemisphere. This surge was first and foremost due to an increase of prognostically favorable ("low risk") papillary thyroid microcarcinomas, for which limited surgical procedures are often sufficient without loss of oncological benefit. These developments called for an update of the previous practice guideline to detail the surgical treatment options that are available for the various disease entities and tumor stages.

METHODS

The present German Association of Endocrine Surgeons practice guideline was developed on the basis of clinical evidence considering current national and international treatment recommendations through a formal expert consensus process in collaboration with the German Societies of General and Visceral Surgery, Endocrinology, Nuclear Medicine, Pathology, Radiooncology, Oncological Hematology, and a German thyroid cancer patient support organization.

RESULTS

The practice guideline for the surgical management of malignant thyroid tumors includes recommendations regarding preoperative workup; classification of locoregional nodes and terminology of surgical procedures; frequency, clinical, and histopathological features of occult and clinically apparent papillary, follicular, poorly differentiated, undifferentiated, and sporadic and hereditary medullary thyroid cancers, thyroid lymphoma and thyroid metastases from primaries outside the thyroid gland; extent of thyroidectomy; extent of lymph node dissection; aerodigestive tract resection; postoperative follow-up and surgery for recurrence and distant metastases.

CONCLUSION

These evidence-based recommendations for surgical therapy reflect various "treatment corridors" that are best discussed within multidisciplinary teams and the patient considering tumor type, stage, progression, and inherent surgical risk.

Medullary thyroid carcinoma: the influence of policy changing in clinical characteristics and disease progression

OBJECTIVE

Medullary thyroid carcinoma (MTC) has varying clinical course. We assessed trends in MTC presentation during the last 34 years.

DESIGN

Retrospective study.

METHODS

One hundred and fifty one patients (44.4% males) were followed for 0.934 years. Patients were classified according to year of diagnosis: group 1, 1977-2000 (n=53) and group 2, 2001-2011 (n=98). Extent of disease at diagnosis, during follow-up, number of surgeries, and pre- and postoperative calcitonin levels were recorded.

RESULTS

In total, 48.34% reported family history of MTC. Group 1 had larger tumors (median 1.70 (intraquartile range (IQR) 1.7) vs 1.1 (1.2) cm, P=0.045, Mann-Whitney), they presented less frequently micro-MTCs (27.8 vs 46.1%, P=0.045), and underwent more multiple surgeries (63.3 vs 20.0%, P<0.001). Group 1 had more frequently progressive disease (35.8 vs 12.2%, P=0.003) and distant metastasis at follow-up (39.7 vs 17.4%, P=0.017). Chronological group (HR 0.15, 95% CI 0.03-0.68, P=0.015) and distant metastases at follow-up (HR 0.07, 95% CI 0.015-0.30, P=0.001) were independently associated with 10-year disease progression (P<0.001). In sporadic cases, cervical lymph node invasion and distant metastases at diagnosis were more frequent in group 1 (72.7 vs 45.5%, P=0.032 and 27.3 vs 5%, P=0.019 respectively); disease stage at diagnosis was more advanced (P=0.004). They underwent more multiple surgeries (P<0.001), presented more frequently distant metastasis at follow-up (67.7 vs 20.0%, P=0.002), had less frequently remission, and more frequently progressive disease (21.4 vs 58.0% and 64.3 vs 14.0% respectively, P<0.001). Postoperative calcitonin levels were higher (P=0.024).

CONCLUSIONS

Recently, an increase in micro-MTCs is observed, while indices of invasiveness and persistence of disease are better. Increased awareness in familial cases, routine calcitonin measurements, and improved surgical procedures could be responsible.