Prognostic factors in well-differentiated follicular-derived carcinoma and medullary thyroid carcinoma

Natural history of medullary thyroid carcinoma in MEN 2 patients carrying a variant at codon 804 in the RET proto-oncogene: A study by the French Neuroendocrine Tumor Group (GTE)

BACKGROUND

RET variants affecting codon 804 are part of the low-to-moderate risk group in the ATA classification, with indications for prophylactic thyroidectomy beyond age of 5years. However, aggressiveness seems to be variable. The objective of this study was to report a large cohort of French carriers of a pathogenic variant at codon 804 in the RET proto-oncogene.

METHODS

Patients from 12 university hospitals with a RET 804 variant were recruited in this retrospective non-interventional French national study, from the French GTE-ENDOCAN-RENATEN database. Incidence and severity (TNM stage and calcitonin levels) of medullary thyroid carcinoma (MTC), phenotype-genotype correlation and clinical outcome were assessed.

RESULTS

A total of 322 patients were analyzed. Index cases (n=65) had a median age at diagnosis of 57years (range: 46-66), and relatives (n=257) a median age of 37years (range: 18-51). Median first calcitonin measurement was 240ng/L (range: 79-1344) in index cases, and 6.7ng/L (range: 0-22) in relatives. In index cases, the pathogenic variant c.2410G>A (p.Val804Met) in RET was more frequent (80% of cases) than c.2410G>C or c.2410G>T (p.Val804Leu). MTC was multifocal, node-positive and metastatic in 64%, 51% and 20% of cases respectively. TNM stage, preoperative calcitonin level and male gender were predictive of persistent disease (defined by postoperative calcitonin>5ng/L) (P<0.001). Ten-year disease-free survival (DFS) was 61%. In total, 113 relatives were operated on: 62% with MTC and 34% with isolated C-cell hyperplasia (CCH); the youngest patients were aged 20 for MTC and 4years for CCH. Ten-year DFS was 90%.

CONCLUSION

The RET pathogenic variants affecting the codon 804 mainly led to low aggressiveness disease, with late presentation and prolonged DFS. We suggest surgery in relatives if calcitonin values are above 6ng/L, instead of 10ng/L. Long-term surveillance is mandatory, since recurrence remains possible several years after surgery.

Well-defined survival outcome disparity across age cutoffs at 45 and 60 for medullary thyroid carcinoma: a long-term retrospective cohort study of 3601 patients

Background

Medullary thyroid cancer (MTC) is a challenging malignancy. The survival outcome of MTC based on AJCC staging system does not render a discriminant classifier among early stages.

Methods

3601 MTC patients from 2000 to 2018 were identified from the Surveillance, Epidemiology, and End Results (SEER) database. Smooth curve fitting, Cox proportional hazard regression and competing risk analysis were applied.

Results

A linear correlation between age and log RR (relative risk of overall death) was detected. Overlaps were observed between K-M curves representing patients aged 45-50, 50-55, and 55-60. The study cohort was divided into 3 subgroups with 2 age cutoffs set at 45 and 60. Each further advanced age cutoff population resulted in a roughly "5%" increase in MTC-specific death risks and an approximately "3 times" increase in non-MTC-specific death risks.

Conclusions

The survival outcome disparity across age cutoffs at 45 and 60 for MTC has been well defined.

Exploring the clinical utility of DPP-IV and SGLT2 inhibitors in papillary thyroid cancer: a literature review

In the realm of clinical management, Papillary Thyroid Cancer (PTC) stands out as a prevalent thyroid malignancy, characterized by significant metabolic challenges, particularly in the context of carbohydrate metabolism. Recent studies have unveiled promising applications of Dipeptidyl Peptidase-IV (DPP-IV) and Sodium-Glucose Cotransporter 2 (SGLT2) inhibitors, which are conventionally employed in the treatment of type 2 diabetes mellitus (T2DM), as potential adjuncts in anticancer therapy. DPP-IV and SGLT2 inhibitors can be imply to counteract the Warburg effect in cancer, with a specific focus on PTC, owing to their potential metabolic advantages and their influence on the tumor microenvironment, achieved by imposing restrictions on glucose accessibility. Consequently, a comprehensive review has been undertaken, involving meticulous examination of the existing body of evidence pertaining to the utilization of DPP-IV and SGLT2 inhibitors in the context of PTC. The mechanisms of action inherent to these inhibitors have been thoroughly explored, drawing upon insights derived from preclinical investigations. Furthermore, this review initiates discussions concerning the implications for future research directions and the formulation of innovative therapeutic strategies for PTC. As the intricate interplay between carbohydrate metabolism, the Warburg effect, and cancer progression garners increasing attention, attaining a comprehensive understanding of the roles played by DPP-IV and SGLT2 inhibitors in PTC management may serve as the cornerstone for novel approaches aimed at enhancing patient care and broadening the spectrum of available therapeutic modalities.

Exploring the clinical utility of angioinvasion markers in papillary thyroid cancer: a literature review

Papillary thyroid cancer (PTC) is the most common type of thyroid cancer, and angioinvasion, the invasion of blood vessels by cancer cells, is a crucial pathological feature associated with disease progression and poor prognosis. Thus, a comprehensive search of scientific databases was conducted to identify relevant studies investigating angioinvasion markers in PTC. The selected studies were reviewed and analyzed to assess the clinical significance and potential utility of these markers in predicting angioinvasion and guiding treatment decisions. Numerous studies have investigated various markers associated with angioinvasion in PTC, including oxidative stress, vascular endothelial growth factor (VEGF), matrix metalloproteinases (MMPs), and other angiogenic factors. The results indicate that increased expression of these markers is correlated with the presence and extent of angioinvasion in PTC. Moreover, some studies suggest that these markers can serve as prognostic indicators and guide therapeutic strategies, such as selecting patients for more aggressive treatment approaches or targeted therapies. The findings from the reviewed literature highlight the potential clinical utility of angioinvasion markers in PTC. The identification and validation of reliable markers can aid in assessing the risk of angioinvasion, predicting disease progression, and optimizing treatment decisions for patients with PTC. However, further research and validation on larger patient cohorts are necessary to establish the robustness and generalizability of these markers in clinical practice.

Immunohistochemistry in the pathologic diagnosis and management of thyroid neoplasms

The use of immunohistochemistry cannot be underestimated in the everyday practice of thyroid pathology. It has evolved over the years beyond the traditional confirmation of thyroid origin to molecular profiling and the prediction of clinical behavior. In addition, immunohistochemistry has served to implement changes in the current thyroid tumor classification scheme. It is prudent to perform a panel of immunostains, and the immunoprofile should be interpreted in light of the cytologic and architectural features. Immunohistochemistry can also be easily performed in the limited cellularity specimen preparation generated from thyroid fine-needle aspiration and core biopsy; however, it will require laboratory validation of immunostains specific to these preparations to avoid diagnostic pitfalls. This review discusses the application of immunohistochemistry in thyroid pathology with a focus on limited cellularity preparations.

PDZK1IP1 gene promotes proliferation, migration, and invasion in papillary thyroid carcinoma

Thyroid cancer is a common malignant tumor for the adult and the potential molecular mechanism of papillary thyroid cancer cell metastasis is still unclear. We used sequencing techniques to analyze paired papillary thyroid carcinoma (PTC) and adjacent thyroid tissue and identified a gene, PDZK1IP1, that was significantly overexpressed in thyroid cancer. We found It has been detected to play an important role in many malignant tumors. But the role in papillary thyroid cancer was still unknown, we decided to find a new marker and therapeutic target for the disease. The present study shows that PDZK1IP1 may be a potential gene that leads to thyroid cancer. In our study, silencing PDZK1IP1 can inhibit PTC cell proliferation, migration, invasion, apoptosis, and cell cycle arrest. This study surmised that PDZK1IP1 was an oncogene that correlated with tumor development.

Ultrasonographic characteristics of medullary thyroid carcinoma according to nodule size: application of the Korean Thyroid Imaging Reporting and Data System and American Thyroid Association guidelines

BACKGROUND

Few studies have categorized ultrasound (US) findings of various sized medullary thyroid carcinomas (MTCs) according to updated guidelines.

PURPOSE

To evaluate and compare the differences in US findings of MTC according to nodule size, using the Korean Thyroid Imaging Reporting and Data System (K-TIRADS) and American Thyroid Association (ATA) guidelines.

MATERIAL AND METHODS

The study included 119 patients with 129 MTC nodules, which were surgically confirmed at our institution between March 1999 and September 2017. Nodules were divided into large (≥1.0 cm) and small (<1.0 cm) groups. US images were analyzed according to the K-TIRADS and ATA guidelines. The differences in US characteristics between small and large nodules were compared using Fisher's exact or Chi-square tests.

RESULTS

Of 129 MTC nodules, 84 (65.1%) were large nodules and 45 (34.9%) were small nodules. According to the nodule size, small MTC nodules were classified more commonly as high suspicion by K-TIRADS and ATA (95.6% and 93.3%, respectively) (P < 0.001), but presented neither cystic change, isoechogenicity, nor low suspicion category by K-TIRADS and ATA. In contrast, large MTC nodules showed more frequently cystic change (15.5%), isoechogenicity (16.7%), smooth margins (50%), or low or intermediate suspicion US features by K-TIRADS and ATA (59.6% and 36.0%, respectively) (all P values < 0.001).

CONCLUSION

Most small MTC nodules are classified as high suspicion on US, whereas large MTC nodules are diagnosed more frequently as low or intermediate suspicion by K-TIRADS and ATA.

African Head and Neck Society Clinical Practice guidelines for thyroid nodules and cancer in developing countries and limited resource settings

BACKGROUND

International thyroid nodule and cancer management guidelines generally fail to take into account potential limitations in diagnostic and treatment resources.

METHODS

Thyroid cancer specialists from the African Head and Neck Society and American Head & Neck Society Endocrine Section developed guidelines for diagnosis and management of thyroid nodules and cancer in low resource settings. Recommendations were based on literature review and expert opinion, with level of evidence defined.

RESULTS

Using the ADAPTE process, diagnostic and treatment algorithms were adapted from the National Comprehensive Cancer Network (NCCN). Low resource settings were simulated by systematically removing elements such as availability of laboratory testing, hormone replacement, imaging, and cytopathology from NCCN guidelines.

CONCLUSIONS

Successful management of thyroid nodules and cancer in low resource settings requires adaptation of treatment methodologies. These guidelines define specific scenarios where either more or less aggressive intervention for thyroid pathology may be advisable based on limited available resources.

Chest wall lymph node metastasis from follicular thyroid carcinoma: a rare case report

BACKGROUND

Distant metastases from follicular thyroid carcinoma are mainly hematogenous and are commonly observed in the lungs and bones. Other rare sites are the parotid gland, skin, brain, ovary, adrenal gland, kidney, pancreas and breast, with chest wall lymph node metastasis being even more rare.

CASE PRESENTATION

Over the past 10 years, three surgeries were performed on a 69-year-old women with a history of follicular thyroid cancer and its metastatic lesions. The patient presented with a 3-month history of masses in the left chest. She underwent detailed examination of the chest wall tumors, and surgery was then performed to resect all of the tumors. Based on the histopathology, these lymph nodes were confirmed to harbor metastatic follicular thyroid carcinoma.

CONCLUSION

This study reports the first case of follicular thyroid carcinoma metastasis to the chest wall lymph node.

Prediction of lateral neck lymph node metastasis according to preoperative calcitonin level and tumor size for medullary thyroid carcinoma

Medullary thyroid carcinoma (MTC) accounts up to 10% of all thyroid cancers, but is responsible for a disproportionate number of deaths. While surgery is the only curative treatment for MTC, indications for lateral neck lymph node (LLN) dissection are controversial. We performed a retrospective review to describe clinical outcomes in 93 MTC patients from July 1995 to March 2015. We analyzed their clinicopathologic factors, and cut-off values of tumor size and calcitonin levels were calculated using a receiver operating characteristic curve. Using the instances of lymph node metastases, the tumor size cut-off value was 0.95 cm (area under curve, AUC = 0.697) in patients with ipsilateral central lymph node (CLN) metastases, 2.25 cm (AUC = 0.793) in contralateral CLN metastases, and 1.75 cm (AUC = 0.753) in ipsilateral LLN metastases. The cut-off values of preoperative calcitonin levels were 226.6 pg/mL (AUC = 0.746) in ipsilateral CLN, 755.0 pg/mL (AUC = 0.840) in contralateral CLN metastases, and 237.0 pg/mL (AUC = 0.775) in ipsilateral LLN metastases. This study supports the notion that ipsilateral LLN metastases occur before contralateral CLN metastases. Therefore, ipsilateral LLN dissection should be considered in patients with contralateral CLN metastases. The extent of surgery should be based on the status of LN metastases, preoperative basal calcitonin level, and tumor size to help individualize the extent of surgery.

All in the family? Analyzing the impact of family history in addition to genotype on medullary thyroid carcinoma aggressiveness in MEN2A patients

Several guidelines for patients with multiple endocrine neoplasia 2A (MEN2A) take into account genotype and family history of medullary thyroid carcinoma (MTC) disease aggressiveness. We sought to determine if an association exists independent of genotype, which could provide important information for counseling MEN2A patients in management of their MTC. Pedigrees of patients with ≥5 family members with MEN2A were retrospectively reviewed. Analysis was performed among kindreds with the most frequently observed codon mutation (RET 634). Familial MTC disease aggressiveness was evaluated using: (1) mean age at diagnosis of MTC, (2) current mean age of carriers without MTC, (3) proportion of kindred with MTC with metastatic disease at diagnosis, (4) proportion of kindred with MTC with metastasis/death from MTC as worst outcome, and (5) proportion of kindred with disease progression. 170 affected patients from 12 different MEN2A kindreds met inclusion criteria. The number of affected family members available for study per kindred ranged from 8 to 43 individuals. A difference in mean age of MTC diagnosis was found in screened patients (p = 0.01); mean age of MTC-free patients did not differ (p = 0.93). No differences were noted among kindreds in disease stage at presentation, worst outcome, or progression; marked variation in these measures was noted within families. In conclusion, a difference in age of MTC diagnosis among different RET 634 kindreds was identified. In contrast, notable intra-familial variability in disease aggressiveness was observed. Based on these findings, we recommend counseling patients with codon 634 mutations that their MTC disease course cannot be predicted by that of their relatives.

Screening of RET gene mutations in Chinese patients with medullary thyroid carcinoma and their relatives

The rearranged during transfection (RET) gene is a proto-oncogene; active mutations frequently occur in medullary thyroid carcinoma (MTC). This study investigated the spectrum of germline RET mutations and clinical features in Chinese hereditary MTC patients. A total of 53 family members from 11 different hereditary MTC families were recruited for detection of RET exon 8, 10, 11, 13, 14, 15, and 16 mutations, in genomic DNA from peripheral blood leucocytes using polymerase chain reaction (PCR) and direct DNA sequencing. Of the 53 participants, eight different germline RET mutations were detected in 37 individuals. These RET mutations were distributed in exons 10, 11, 13, and 16. The most frequent RET mutation was localized at exon 11 codon 634 (67.6 %; 25/37) and the most prevalent mutation was C634R (37.8 %; 14/37). The most frequent phenotype was multiple endocrine neoplasia type 2A (MEN2A). The incidences of MTC, pheochromocytoma, and hyperparathyroidism in the MEN2A patients were 100, 36.4 and 18.2 %, respectively. The phenotype of families with Y606C or L790F mutation was categorized as familial medullary thyroid carcinoma. Moreover, one proband was identified with multiple endocrine neoplasia type 2B and carried a de novo mutation of M918T. Two families with C618S/Y mutation were categorized as unclassified multiple endocrine neoplasia type 2. Our results further substantiate that most germline mutations of the RET proto-oncogene were localized at codon 634 in Chinese hereditary MTC patients and carriers. RET mutation at codon 634 was always associated to the phenotype of MEN2A. Screening of RET mutations should be probably limited to exons 10, 11, 13 and 16 initially to be cost-effective in China.

Patterns of metastasis in follicular thyroid carcinoma and the difference between early and delayed presentation

Introduction Follicular thyroid cancer (FTC) has a good prognosis if treated early. The aim of this study was to look at the difference in outcomes in those who presented with metastasis early or late in their disease. Methods A retrospective cohort study was conducted of patients diagnosed with FTC (n=91) treated between 2000 and 2013. Demographic, laboratory, pathological and survival data were collected and analysed. Results Metastatic FTC was diagnosed in 20 cases (22%). The median age at diagnosis was 65 years (range: 17-86 years) and 65% of the patients were female. Twelve patients (60%) were diagnosed with metastatic disease at presentation, with the bones being the most common site (75%). In the remaining eight cases (40%), metastasis developed at a median of 4.5 years (range: 2-8 years) after initial thyroid surgery, lungs being the most common site (50%). Eighteen patients (90%) underwent surgical intervention for the primary disease. Sixteen patients (80%) received adjuvant radioactive iodine and eight (40%) received external beam radiotherapy. Widely invasive follicular cancer was the predominant histological diagnosis (90%). No prognostic association was observed with any of the parameters studied. The overall disease specific mortality rate was 40%. There was no significant difference in mortality between those who presented with metastatic disease and those who developed metastasis during the follow-up period (33% vs 50%, p=0.61). Conclusions The clinical outcome and prognosis for cases with metastatic disease is generally poor. Despite this, almost half of the patients in our study were still alive at a median follow-up of 5.5 years, regardless of whether they were diagnosed with metastatic disease on initial presentation or whether they developed metastasis after initial thyroid surgery.

[Postoperative external beam radiotherapy for medullary thyroid carcinoma with high risk of locoregional relapse]

PURPOSE

To assess the outcome of locally advanced medullary thyroid carcinoma treated with surgery and adjuvant external beam radiotherapy.

PATIENTS AND METHODS

Twenty-nine consecutive patients with non-metastatic medullary thyroid carcinoma treated in our institution between January 1995 and December 2012 were retrospectively evaluated. All underwent curative-intended optimal surgery, followed by external beam radiotherapy because of high risk of locoregional relapse. Twelve patients were stage III, 16 IVa and 1 IVb. Positive surgical margins were present in 11 cases (10 R1 and 1 R2). Median and average preradiotherapy serum calcitonin were 141pg/mL and 699pg/mL, respectively. Fourteen patients received 3D-conformal radiotherapy and 15 received intensity-modulated radiotherapy. Median prescribed dose was 63Gy to the high-risk volumes and 54Gy to the low-risk volumes. Treatment was delivered in 30 fractions. The median gap between surgery and radiotherapy was 1.9months. Median follow-up was 76.4months.

RESULTS

Kaplan-Meier estimates of 5-year locoregional relapse-free survival and overall survival were 79 and 96 %, respectively. Among the five locoregional relapses, two were related to a macroscopic metastatic cervical lymph node that was unfortunately not removed during the lymphadenectomy. Eight of ten patients with microscopic positive margins (R1) were controlled regarding the thyroidectomy bed. Eight patients had normal serum calcitonin after external beam radiotherapy, of whom only one developed a locoregional relapse during follow-up. Regarding the 21 patients with persistent positive serum calcitonin after treatment, only ten developed a macroscopic locoregional or distant relapse. One grade III and no grade IV acute morbidity were reported. Fifteen patients reported grade II chronic morbidity and no grade III/IV.

CONCLUSION

Maximal surgery followed by adjuvant external beam radiotherapy as a treatment for locally advanced medullary thyroid carcinoma provides a high rate of long-term locoregional control and overall survival with limited toxicity. Postoperative external beam radiotherapy should be considered when patients present features indicating a high risk of locoregional relapse.

The Management of Medullary Thyroid Carcinoma in the Era of Targeted Therapy

Medullary thyroid cancer (MTC) is a rare cancer comprising approximately 5% of all thyroid cancers. The majority arises sporadically but around 25% are hereditary forming part of the Multiple Endocrine Neoplasia (MEN) type 2 syndromes. The initial management is surgical, the extent of resection determined by radiological stage, presence of and specific REarranged during Transfection (RET) oncogene mutation and level of serum calcitonin. External beam radiotherapy may be utilised in the adjuvant setting to improve local control rates. Conventional cytotoxic agents remain essentially futile in the management of advanced MTC with response rates of around 15-20% at best. Over the last decade, alongside a greater understanding of the molecular pathogenesis of MTC we have seen the development of small molecule agents including tyrosine kinase inhibitors targeting vascular endothelial growth factor receptors (VEGFRs) and RET with activity in advanced MTC. This review will examine the evidence for this therapeutic approach, when to consider initiating and how to manage toxicities arising from such therapies in the treatment of advanced MTC.

Association between prognostic factors and clinical outcome of well-differentiated thyroid carcinoma: A retrospective 10-year follow-up study

Differentiated thyroid carcinoma (DTC) is one of the most common metabolic disorders and accounts for 98% of all cases of thyroid cancer. Previously, a number of studies have investigated the prognostic factors associated with well-differentiated thyroid carcinoma (WDTC); however, these studies yielded conflicting results. The current study used a retrospective study design to collect data from WDTC patients who had received the same treatment regimen from the same institute, with a minimum follow-up of 10 years. The De Groot staging system was used to classify WDTC in a total of 320 patients (240 females and 80 males). Among the subjects, the pathological subtypes identified were as follows: Papillary carcinoma (240 cases, 75%), follicular carcinoma (67 cases, 21%) and Hürthle cell carcinoma (13 cases, 4%). Prognostic factors that significantly affected the clinical outcome of the disease were advanced age (P=0.001), tumor size (P=0.03), presence of thyroglobulin (P=0.001) and De Groot stage (P=0.005). The 10-year follow-up study revealed that WDTC is associated with a high survival rate of 96% (307/320 patients survived) and a low mortality rate (4%).

Comparative effectiveness in thyroid cancer: key questions and how to answer them

Controversies in treatment of thyroid cancer remain despite numerous published studies. Robust comparative effectiveness studies examining: (1) the role of prophylactic central compartment neck dissection (pCCND) in patients with papillary thyroid cancer (PTC); (2) the use of post-operative radioactive iodine (RAI) ablation therapy following total thyroidectomy; (3) use of low versus high doses of I-131 in RAI therapy; (4) thyroid hormone withdrawal (THW) versus recombinant thyroid stimulating hormone (rhTSH) prior to RAI; and (5) the role of routine measurement of serum calcitonin levels are needed to help strengthen existing treatment recommendations. Reasons for the controversies and suggestions for quality comparative effectiveness studies are discussed.

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.

Medical management of metastatic medullary thyroid cancer

Medullary thyroid cancer (MTC) is an aggressive form of thyroid cancer that occurs in both heritable and sporadic forms. Discovery that mutations in the rearranged during transfection (RET) proto-oncogene predispose to familial cases of this disease has allowed for presymptomatic identification of gene carriers and prophylactic surgery to improve the prognosis of these patients. A significant number of patients with the sporadic type of MTC and even those with familial disease still present with lymph node or distant metastases, making surgical cure difficult. Over the past several decades, many different types of therapy for metastatic disease have been attempted with limited success. Improved understanding of the molecular defects and pathways involved in both familial and sporadic MTC has resulted in new hope for these patients with the development of drugs targeting the specific alterations responsible. This new era of targeted therapy with kinase inhibitors represents a significant step forward from previous trials of chemotherapy, radiotherapy, and hormone therapy. Although much progress has been made, additional agents and strategies are needed to achieve durable, long-term responses in patients with metastatic MTC. This article reviews the history and results of medical management for metastatic MTC from the early 1970s up until the present day.

New developments in the diagnosis and treatment of thyroid cancer

Thyroid cancer exists in several forms. Differentiated thyroid cancers include those with papillary and follicular histologies. These tumors exist along a spectrum of differentiation, and their incidence continues to climb. A number of advances in the diagnosis and treatment of differentiated thyroid cancers now exist. These include molecular diagnostics and more advanced strategies for risk stratification. Medullary cancer arises from the parafollicular cells and not the follicular cells. Therefore, diagnosis and treatment differs from those of differentiated thyroid tumors. Genetic testing and newer adjuvant therapies have changed the diagnosis and treatment of medullary thyroid cancer. This review will focus on the epidemiology, diagnosis, workup, and treatment of both differentiated and medullary thyroid cancers, focusing specifically on newer developments in the field.

Sociodemographic Predictors of Survival in Differentiated Thyroid Cancer: Results from the SEER Database

Background. Differentiated thyroid carcinoma (DTC) is prognosticated upon a combination of tumor characteristics, such as histology and stage, and patient age. DTC is also notable for having a strong female predominance. Using a nationwide database with long follow-up times, we explored the interplay between tumor biology and patient characteristics in predicting mortality. Methods. The Surveillance, Epidemiology, and End Results (SEER) registry data 1973–2005 was examined for patients with DTC as their only known malignancy. Cox multivariate analyses were used to generate mortality hazard ratios to evaluate the effects of age, gender, ethnicity, and marital status. Results. We identified 55,995 patients with DTC as their only malignancy. Consistent with the existing literature, the tumors are primarily diagnosed in women (77.5%), and predominantly affect Caucasians (78.3%). Female gender had a protective effect resulting in a 37% decrease in mortality. Age at diagnosis predicted mortality over age 40. Black ethnicity was associated with a 51% increase in mortality compared to Caucasians. Conclusion. Multiple demographic factors predict mortality in patients with DTC after adjusting for tumor characteristics, and they appear to have complex interactions. Recognizing the importance of these factors may enable clinicians to better tailor therapy.

Familial thyroid neoplasia: impact of technological advances on detection and monitoring

PURPOSE OF REVIEW

To weigh the clinical impact of new technological insights into heritable thyroid malignancies.

RECENT FINDINGS

Medullary thyroid carcinoma and familial nonmedullary thyroid cancers represent the small minority of thyroid cancers that are inherited. New insights into the genetic alterations and molecular mechanisms implicated in these tumors are serving to refine the clinical tools available for their initial diagnosis as well as subsequent follow-up. In addition to an analysis of rearranged during transfection mutations and calcitonin profiles in medullary thyroid carcinoma, this review includes emphasis on familial nonmedullary thyroid cancer syndromes, including genetic findings in familial papillary thyroid cancer, familial adenomatous polyposis, Cowden syndrome, Carney complex, and Werner syndrome.

SUMMARY

Genetic mutational information is increasingly available on medullary and familial nonmedullary thyroid cancer and their associated syndromes. The clinical significance of this information for affected patients and their families continues to undergo evaluation.

Medullary thyroid cancer: management guidelines of the American Thyroid Association

BACKGROUND

Inherited and sporadic medullary thyroid cancer (MTC) is an uncommon and challenging malignancy. The American Thyroid association (ATA) chose to create specific MTC Clinical Guidelines that would bring together and update the diverse MTC literature and combine it with evidence-based medicine and the knowledge and experience of a panel of expert clinicians.

METHODS

Relevant articles were identified using a systematic PubMed search and supplemented with additional published materials. Evidence-based recommendations were created and then categorized using criteria adapted from the United States Preventive Services Task Force, Agency for Healthcare Research and Quality.

RESULTS

Clinical topics addressed in this scholarly dialog included: initial diagnosis and therapy of preclinical disease (including RET oncogene testing and the timing of prophylactic thyroidectomy), initial diagnosis and therapy of clinically apparent disease (including preoperative testing and imaging, extent of surgery, and handling of devascularized parathyroid glands), initial evaluation and treatment of postoperative patients (including the role of completion thyroidectomy), management of persistent or recurrent MTC (including the role of tumor marker doubling times, and treatment of patients with distant metastases and hormonally active metastases), long-term follow-up and management (including the frequency of follow-up and imaging), and directions for future research.

CONCLUSIONS

One hundred twenty-two evidence-based recommendations were created to assist in the clinical care of MTC patients and to share what we believe is current, rational, and optimal medical practice.

External beam radiation therapy for thyroid cancer

This article discusses the role of external beam radiotherapy (XRT) in the management of well-differentiated thyroid cancer (WDTC), medullary thyroid cancer, and anaplastic thyroid cancer. Although there are no randomized controlled studies on the use of XRT in thyroid cancer, evidence supports its use to treat gross disease after surgery or unresectable cancer and its use as an adjuvant after resection of a known high-risk disease in WDTC, and, to a lesser extent, in medullary thyroid cancer. The use of XRT for the palliation of symptomatic disease and recent advances in the technology of radiation delivery also will be discussed.

Poorly differentiated follicular thyroid carcinoma: prognostic factors and relevance of histological classification

OBJECTIVE

Poorly differentiated follicular thyroid carcinoma (PDFC) is a tumor of follicular cell origin with attributes intermediate between well-differentiated carcinomas and anaplastic carcinomas, but neither a clear histological description nor an established definition of prognostic indicators are available.

DESIGN

This study correlates the clinical outcome and survival of 40 PDFC patients with histological architecture, cytological characteristics, and expression of various markers of cell proliferation and differentiation (cyclin A, cyclin B1, cyclin D1, cyclin E, Ki67, thyroperoxidase, galectin 3, dual oxidase [Duox], vascular endothelial growth factor, epidermal growth factor receptor, and p53).

MAIN OUTCOME

At 5 years, the overall survival rate was 63% and the metastasis-free survival rate was 57%. An older age at the time of diagnosis and a larger tumor size were associated with an increased risk of distant metastases and of cancer-related death. Polymorph architecture was associated with a reduced risk of metastases, whereas a high expression of Duox was associated with a reduced risk of death. In these patients with PDFC, no other histological features or expression of any other marker had a prognostic significance.

CONCLUSION

PDFC has a more aggressive behavior than well-differentiated carcinomas; prognosis is related to indicators that are also relevant in patients with well-differentiated carcinomas.

Thyroid carcinomas with a variable insular component

BACKGROUND

An insular growth pattern may be observed focally both in papillary and follicular thyroid carcinoma. The aim of the current study was to determine whether a greater extension of the insular component (IC) influences different clinical and histologic features at diagnosis, and a different tumor aggressiveness in terms of frequency in the occurrence of metastases as well as survival.

METHODS

Thirty-three patients with histopathologic findings consistent with IC were included in the study. IC was focal (<50% of the tumor area) in 16 patients and predominant (>50% of the tumor area) in 17 patients. These 2 groups were compared with a control group of 66 patients with differentiated thyroid carcinoma.

RESULTS

At diagnosis, carcinomas with predominant IC differed from those with focal IC with regard to greater tumor size and a higher frequency of extrathyroidal extension and distant metastases. Patient follow-up ranged from 5 to 188 months. The cumulative rate of distant metastases was significantly higher in patients with predominant IC. At the time of last follow-up, carcinomas with predominant IC demonstrated a lesser frequency of disease-free outcome (P = .002) and a higher number of tumor-related deaths (P = .002), either when distant metastases were present (P = .03) or absent (P = .05) at the time of diagnosis.

CONCLUSIONS

The presence of predominant IC is associated with a poor prognosis in terms of ongoing disease or death. Predominant IC should be considered a separate entity from not only the classical papillary or follicular carcinomas but also the focal IC tumor.

Predictors of outcome in patients with papillary thyroid carcinoma

AIM OF THE STUDY

To evaluate prognostic factors with respect to the outcome in a consecutive series of patients with papillary thyroid carcinoma (PTC) treated at the same institution during a 20-year-period, and to evaluate further the predictive ability of outcome of the pTNM, AMES and MACIS prognostic systems in these patients.

MATERIALS AND METHODS

Two hundred and twenty consecutive patients operated on for primary PTC at the Karolinska Hospital between 1980 and 1999 were examined retrospectively. Patient and tumour characteristics at the time of surgery were compared to the patients' outcomes. Univariate and multiple logistic regression analyses were used to identify independently significant prognostic factors with respect to the outcome. In addition, the classification of the patients according to the pTNM, AMES and MACIS prognostic systems were compared to the outcomes.

RESULTS

At the end of the follow-up period 201 patients were still alive without disease, 6.5% had died from PTC and 2.5% were alive with persisting disease. In 16 patients, radical surgery could not be performed due to extensive tumour growth and/or distant metastases. Recurrences were detected in 14% of the patients considered as radically operated. The strongest independent predictors for local or distant recurrences and poor clinical outcome were the lack of radical surgery and increasing tumour size. In this investigation MACIS appeared to be the better system, regarding efficacy in predicting the outcome of PTC.

CONCLUSION

Removal of all tumour tissue appears most important to a favorable outcome and in our patients MACIS appears the most useful prognostic system taking completeness of resection into account.

Prognostic factors and the effect of treatment with radioactive iodine and external beam radiation on patients with differentiated thyroid cancer seen at a single institution over 40 years

OBJECTIVES

To assess the prognostic factors and the role of radioactive iodine (RAI) and external beam radiotherapy (RT) in patients with differentiated thyroid cancer.

DESIGN

A retrospective review of 729 patients treated between 1958 and 1998. The median follow-up was 11.3 years (range 0.3-39.8 years). Primary outcomes included time to cause-specific survival and time to local-regional relapse. Baseline and treatment variables were assessed for statistical significance using the Cox proportional hazards model.

RESULTS

The 10-year cause-specific survival (CSS) was 87.3% and the 10-year local-regional relapse-free rate (LRFR) was 84.9%. In multivariate analysis there was no statistically significant improvement in CSS with more aggressive treatment (i.e. more extensive surgery, the administration of RAI and/or RT). By multivariate analysis the use of RAI resulted in a statistically significant improvement in LRFR (hazard ratio 0.5; 95% confidence interval 0.3-0.8; P = 0.007). In low-risk patients at AJCC stage I < or = 45 years, there was no apparent benefit from RAI. For patients over 60, with extrathyroid extension but no gross residual disease (n = 70), adjuvant external RT resulted in statistically significantly higher CSS (10-year CSS 81.0%vs. 64.6%, P = 0.04) and LRFR (10-year LRFR 86.4%vs. 65.7%, P = 0.01).

CONCLUSIONS

The use of RAI was associated with improved LRFR but not in low-risk patients. External beam RT improved LRFR and CSS in high-risk patients.

Expression of cdc25B and cdc25A in medullary thyroid carcinoma: cdc25B expression level predicts a poor prognosis

Cdc25B and cdc25A phosphatases are prominent stimulators of cell cycle progression and have been suggested to play oncogenic roles. In this study, we immunohistochemically investigated the expression of these phosphatases in medullary thyroid carcinoma. Cdc25B was positive in 35.8% of cases examined. Its positivity was linked only to patient age. However, patients with cdc25B-positive tumors showed a significantly worse disease-free survival rate (P=0.0210) than those with cdc25B-negative tumors. Cdc25A was positive in only 17.2% of cases and was not related to clinicopathological parameters or prognosis. These findings suggest that cdc25B can be regarded as having prognostic significance and as a novel marker of biologically aggressive characteristics in this carcinoma.

Expression of Jun activation domain-binding protein 1 and p27 (Kip1) in thyroid medullary carcinoma

AIMS

p27 is a prominent regulator of cell proliferation by universally inhibiting the cell cycle, while Jun activation domain-binding protein 1 (Jab1), a multifunctional cell signaling protein, contributes to carcinoma progression by degrading p27. In this study, we investigated the expression of these proteins in medullary thyroid carcinoma.

METHODS

We immunohistochemically examined Jab1 and p27 expression in 64 medullary thyroid carcinomas.

RESULTS

Of the 64 cases examined, decreased p27 expression was observed in 38 cases (59.4%). The p27 expression level was inversely linked to tumour size as well as plasma calcitonin level. Jab1 expression level was generally high, and 46 cases (71.9%) were classified as overexpressing Jab1. The incidence was higher than those in papillary and follicular carcinomas, which were previously reported. Jab1 expression level was inversely linked to that of p27, and all five cases with only cytoplasmic but not nuclear staining of p27 overexpressed Jab1.

CONCLUSIONS

These findings suggest that (1) decrease in p27 expression may contribute to local tumour growth; (2) Jab1 expression is related to the progression of medullary carcinoma by decreasing the amount of p27 in the cell and accelerating its degradation; and (3) Jab1 may play a more vital role in the pathogenesis of medullary carcinoma than papillary and follicular carcinomas.

Polo-like kinase 1 expression in medullary carcinoma of the thyroid: its relationship with clinicopathological features

OBJECTIVE

Polo-like kinase 1 (PLK1) is one of the serine-threonine kinases that contributes to cell mitosis and is regarded as a marker of cellular proliferation. However, its protein expression in human carcinoma has not been studied in depth. In this study, we investigated PLK1 expression in medullary thyroid carcinoma by means of immunohistochemistry.

METHODS

We immunohistochemically investigated PLK1 expression in 67 cases of medullary thyroid carcinoma.

RESULTS

The PLK1 expression level was elevated in 43 of the 67 cases (64.1%). Furthermore, the expression level was directly linked to lymph node metastasis, advanced stage and male sex. All patients who were negative for PLK1 expression are currently alive without tumor recurrence, while 6 of the 43 PLK1-positive patients showed recurrence and 3 have already died of this disease.

CONCLUSIONS

These findings suggest that PLK1 expression significantly reflects aggressive characteristics of medullary thyroid carcinoma.

Differentiated thyroid cancer and outcome in iodine deficiency

AIMS

Factors influencing prognosis and long-term outcome of thyroid cancer have been described by several groups. We wished to asses the previously described prognostic factors in a moderately iodine deficient region in Hungary.

METHODS

Four hundred and fifty-four out of 492 patients who had surgery for papillary thyroid cancer (PTC, 386 cases) and follicular thyroid cancer (FTC, 106 cases) between 1971 and 1998 were analyzed. Survival curves were compared using the Kaplan-Meier method and Cox regression analysis.

RESULTS

The 10 and 20-year survival rates were 87.9 and 84% for PTC, and 78.2 and 78.2% for FTC. In PTC, extrathyroidal invasion (p<0.0001), lymph node metastasis (p<0.0001), distant metastasis (p<0.0001), and age over 40 years (p=0.002) were significant adverse predictors. In FTC, extrathyroidal invasion (p=0.003) distant metastases (p<0.0001), and age over 40 years (p=0.011) were significant adverse predictors.

CONCLUSION

Iodine intake did not appear to influence survival. The incidence of follicular cancer, which has less favourable prognosis, was higher in iodine deficient regions. This supports the importance of iodine supplementation in these areas.

Molecular evidence of anaplastic transformation in coexisting well-differentiated and anaplastic carcinomas of the thyroid

Anaplastic thyroid cancer is a rare but nearly universally fatal tumor. Epidemiologic data suggest that many anaplastic thyroid carcinomas arise from transformation of preexisting or coexisting well-differentiated thyroid carcinomas. At the molecular level, the mutations responsible for the anaplastic transformation are incompletely understood, although the mutational events are thought to involve tumor suppressor genes. To examine transformation from a well-differentiated thyroid carcinoma to anaplastic carcinoma, we studied coexisting well-differentiated (Hürthle cell and papillary carcinoma) and anaplastic tumors with a molecular genotyping panel of tumor suppressor genes associated with thyroid neoplasia. The patterns of allelic loss in our results showed that the majority of cases have a core of conserved mutations in the two morphologically distinct areas and substantial increases in mutation rates in the anaplastic components.

Low expression of sodium iodide symporter identifies aggressive thyroid tumors

A decreased radioiodine uptake is frequently detected in differentiated thyroid carcinomas (DTC) and is associated with high recurrence rate and reduced survival. We investigated the correlation between NIS mRNA expression levels in the primary tumor and patient outcome using a quantitative real-time RT-PCR method. NIS expression was decreased in 17 DTC (21.04+/-39.66 pg Eq) compared to four autoimmune thyroid disease (180.51+/-92.63 pg Eq) and 14 normal tissues (75.71+/-66.98 pg Eq) (p<0.0001). The 17 thyroid differentiated carcinoma patients were submitted to surgery complemented by radioiodine ablation and had at least 24 months of follow-up, under levothyroxine continued suppressive therapy. According to their outcome, we could characterize a group of papillary carcinoma patients with aggressive carcinomas, whose NIS mRNA levels were markedly lower than a group with non-aggressive carcinomas (0.62+/-0.79 versus 54.87+/-53.79; p<0.005). We suggest that the quantification of NIS mRNA relative levels in the primary tumor may predict poor outcome.

Modern Management of Differentiated Thyroid Cancer

The outcome in differentiated thyroid cancer is excellent. Simple prognostic factors, including the age of the patient at diagnosis, the size of the primary cancer, completeness of surgical excision, and the presence of distant metastases, allow the clinician to judge how a patient will do. The preferred treatment is total thyroidectomy and in selected patients radioactive iodine can be used to ablate residual thyroid or functioning metastases in lymph nodes and distant sites. The physician has two excellent methods for following the patient: the whole-body scan with radionuclides of iodine, and measurement of serum thyroglobulin. In patients with elevated thyroglobulin and negative scans with radioactive iodine, there is increasing evidence that positron emission tomography (PET) is helpful in locating the site of thyroglobulin production.

Incidence and survival of Swedish patients with differentiated thyroid cancer

Papillary (PTC) and follicular (FTC) thyroid cancers are rare disorders but are, nevertheless, among the most common cancers in individuals below 40 years of age. From the population-based Swedish Cancer Registry we identified 3,588 individuals with PTC and 1,966 with FTC during 1958-87. Histopathology was determined by examining the original histopathology reports. The relative survival ratio (RSR) was used as the measure of patient survival. Incidence of both PTC and FTC was higher among women, especially for PTC and particularly during the fertile part of female life. Incidence of PTC increased significantly over time, a trend that was not observed for FTC. Five-year relative survival appeared to be higher for patients diagnosed with PTC compared to FTC, although this difference was almost completely explained by the confounding effect of age. Patients with PTC experience lower mortality during the period 7-20 years after diagnosis. Excess mortality was lower among women, although the magnitude of the difference varied with age and histopathology. In contrast to our perceptions based on clinical practice, we observed no difference in excess mortality between patients diagnosed with PTC and FTC during the years immediately after diagnosis (where the majority of deaths occur). Our data suggest that there may exist a subgroup of thyroid tumors with superior prognosis diagnosed in women during the fertile part of female life. Sex hormones may play a role in the etiology of these tumors.

[Thyroid tumors]

The vast majority of thyroid tumours are epithelial. In contrast to thyroid adenoma, which is a common tumour, thyroid carcinomas make up only 1% of all human malignancies. Routine pathology is regularly confronted with a differential diagnosis involving thyroid adenoma and carcinoma, as well as particular variants of these tumours. This paper deals with the standardised gross and histological examination, as well as the impact of immunohistochemistry and intraoperative frozen sections on thyroid pathology.