Progression of Papillary Thyroid Carcinoma to Anaplastic Carcinoma in Metastatic Lymph Nodes: Solid/Insular Growth and Hobnail Cell Change in Lymph Nodes Are Predictors of Subsequent Anaplastic Transformation

Poorly differentiated thyroid carcinomas: conceptual controversy and clinical impact

Poorly differentiated thyroid carcinomas (PDTC) are rare diseases; nevertheless, they account for the majority of deaths from non-anaplastic follicular cell-derived thyroid carcinomas. Establishing the diagnosis and treatment of PDTC is challenging given the low incidence and the lack of standardization of diagnostic criteria. These limitations hamper the ability to compare therapeutic modalities and outcomes between recent and older studies. Recently, the 5th edition of the classification of endocrine tumors has been published, which includes changes in nomenclature and the addition of the disease entity of "differentiated high-grade follicular cell-derived carcinomas". On the other hand, the recently witnessed advances in molecular diagnostics have enriched therapeutic options and improved prognosis for patients. We herein review the various historical variations and evolution in the diagnostic criteria for PDTC. This systematic review attempts to clarify the evolution of the histological and molecular characteristics of this disease, its prognosis, as well as its treatment options.

Management of aggressive variants of papillary thyroid cancer

PURPOSE OF REVIEW

The aim of this study was to provide a timely and relevant review of the latest findings and explore appropriate management of aggressive variants of papillary thyroid cancer (AVPTC).

RECENT FINDINGS

In general, AVPTCs tend to exhibit more invasive characteristics, a lack of responsiveness to radioiodine, increased occurrences of regional spreading, distant metastases and higher mortality rates. Meanwhile, each variant showcases unique clinical and molecular profiles.

SUMMARY

Given the elevated risk of recurrence postsurgery, a more aggressive strategy may be necessary when suspected preoperatively, particularly for those presenting with invasive features. Decision on the extent of surgical treatment and adjuvant therapy is individualized and made by experienced clinicians and multidisciplinary teams based on the clinical presentation, presence of aggressive features and molecular profile. Future studies on development of personalized medicine and molecular target therapy may offer tailored treatment options.

Challenging Case of Anaplastic Thyroid Cancer With Unusual Clinical and Histological Features: A Diagnostic Dilemma With Undifferentiated Pleomorphic Sarcoma

Thyroid cancer is a common malignancy worldwide, and its incidence is increasing rapidly, especially in women. In the majority of cases, it presents solely with a palpable neck swelling. Less commonly, the disease manifests with symptoms of advanced stages, such as superior vena cava (SVC) obstruction and indications of recurrent laryngeal nerve invasion. Anaplastic thyroid cancer is a rare variant of thyroid cancer and is considered to have one of the poorest prognoses, and its diagnosis and treatment are challenging. On the other hand, undifferentiated pleomorphic sarcoma is a differential diagnosis with many clinical and histological similarities, which can only be confirmed through immunohistochemical studies. We herein report a challenging case of a 69-year-old female patient who presented with obstructive symptoms, diagnosed with anaplastic thyroid cancer exhibiting unusual clinical and histological features.

FOXE1 Gene is a Probable Tumor Suppressor Gene with Decreased Expression as Papillary Thyroid Cancers Grow, and is Absent in Anaplastic Thyroid Cancers

Papillary thyroid carcinoma (PTC), the most prevalent cancer of the thyroid, is more common in women than in men. To uncover the expression profile of FOXE1 gene in PTC tumor etiology. Microarray and RNA sequencing data on PTC in humans were analyzed. Eleven PTC tumor tissue samples and their neighboring normal tissue samples were collected. RT-qPCR was performed. Data normality, ROC construction, and logistic regression analysis were conducted. PTC tumors, normal tissues surrounding tumors, patients of different sexes and ages, metastasizing tumors, and tumor variants were assessed for FOXE1 expression. Eleven PTC tissues were obtained from seven women and four men. Among the PTC subtypes, there were two FV-PTCs, four C-PTCs, one microcarcinoma, and four tissues with an unknown subtype. FOXE1 gene expression was significantly increased in PTC tumors with dimensions less than 10 mm (relative expression = 14.437, p = 0.050). A significant increase in FOXE1 gene expression was observed in the normal tissue adjacent to the tumor, which was less than 10 mm in size, compared to the normal tissue adjacent to the tumor, which was larger than 10 mm (relative expression = 41.760, p = 0.0001). Females diagnosed with PTC showed a significant reduction in FOXE1 mRNA levels compared to their male counterparts (relative expression = 0.081, p = 0.042). In contrast to adjacent normal tissue, there was a significant reduction in FOXE1 gene expression in FV-PTC (relative expression = 0.044 and p = 0.0001). PTC tumors under 10mm had higher FOXE1 gene expression than larger tumors; normal tissue adjacent to smaller tumors also had higher FOXE1 expression. Females with PTC, regardless of their subtype, expressed less FOXE1 mRNA than males. FV-PTC tissues exhibited lower expression of FOXE1 mRNA than their adjacent normal tissues.

HHV-6A Infection of Papillary Thyroid Cancer Cells Induces Several Effects Related to Cancer Progression

Recent studies have shown that thyrocytes are permissive to HHV-6A infection and that the virus may contribute to the pathogenesis of autoimmune thyroiditis. Thyroid autoimmune diseases increase the risk of papillary cancer, which is not surprising considering that chronic inflammation activates pathways that are also pro-oncogenic. Moreover, in this condition, cell proliferation is stimulated as an attempt to repair tissue damage caused by the inflammatory process. Interestingly, it has been reported that the well-differentiated papillary thyroid carcinoma (PTC), the less aggressive form of thyroid tumor, may progress to the more aggressive follicular thyroid carcinoma (FTC) and eventually to the anaplastic thyroid carcinoma (ATC), and that to such progression contributes the presence of an inflammatory/immune suppressive tumor microenvironment. In this study, we investigated whether papillary tumor cells (BCPAP) could be infected by human herpes virus-6A (HHV-6A), and if viral infection could induce effects related to cancer progression. We found that the virus dysregulated the expression of several microRNAs, such as miR-155, miR-9, and the miR-221/222 cluster, which are involved in different steps of carcinogenesis, and increased the secretion of pro-inflammatory cytokines, particularly IL-6, which may also sustain thyroid tumor cell growth and promote cancer progression. Genomic instability and the expression of PTEN, reported to act as an oncogene in mutp53-carrying cells such as BCPAP, also increased following HHV-6A-infection. These findings suggest that a ubiquitous herpesvirus such as HHV-6A, which displays a marked tropism for thyrocytes, could be involved in the progression of PTC towards more aggressive forms of thyroid tumor.

Factors Associated with Survival in Anaplastic Thyroid Carcinoma: A Multicenter Study from the ENDOCAN-TUTHYREF Network

Background: Anaplastic thyroid carcinoma (ATC) is a rare and frequently fatal type of thyroid cancer. The degree of heterogeneity in survival rates for ATC is incompletely studied. This study evaluated the factors associated with overall survival (OS) of patients with ATC using multicenter real-world data from a national tertiary care center network in France. Methods: In this multicenter, retrospective cohort study, all patients with ATC diagnosed between 2010 and 2020 were identified from the national database of the French ENDOCAN-TUTHYREF network. Factors associated with OS were examined in multivariable analyses using Cox proportional hazards models. Results: The study included 360 patients. Of these, 220 (61%) were female and the median age was 72 years (interquartile range: 62-80). The percentages of patients with pure and mixed (synchronously-transformed) ATC (p-ATC and st-ATC) were 62.5% and 26.7%, respectively. The median OS was 6.8 months [confidence interval, CI: 5.5-8.1]: not reached for stage IVa, 11.4 months [8.2-17.8] for IVb, and 4.6 months [3.5-5.7] for IVc. Surgery, radiation therapy to the neck, chemotherapy, and best supportive care were administered to 69 (19.2%), 214 (59.4%), 254 (70.6%), and 66 (18.3%) patients, respectively. In a multivariable analysis, including stage IVb-IVc patients, significantly higher OS was observed in patients with Eastern Cooperative Oncology Group performance-status of 0-1 (hazard ratio [HR], 0.6; [CI, 0.4-0.9], p < 0.02), stage IVb [HR, 0.5; CI, 0.4-0.8, p < 0.001], and multimodal treatment (surgery and chemoradiotherapy) [HR, 0.07; CI, 0.04-0.1, p < 0.001]. Variables associated with significantly worse OS included: p-ATC (vs. st-ATC) [HR, 1.83; CI, 1.33-2.51, p = 0.001] and a neutrophil-to-lymphocyte ratio (NLR) >5.05 [HR, 2.05, CI, 1.39-3.05, p < 0.001]. Conclusions: Factors independently associated with improved OS in ATC included: European Cooperative Oncology Group performance status, disease stage, multimodality treatment, synchronously transformed ATC, and lower NLR. Long-term OS was observed in selected patients with ATC who underwent multimodal treatment.

A clinically useful and biologically informative genomic classifier for papillary thyroid cancer

Clinical management of papillary thyroid cancer depends on estimations of prognosis. Standard care, which relies on prognostication based on clinicopathologic features, is inaccurate. We applied a machine learning algorithm (HighLifeR) to 502 cases annotated by The Cancer Genome Atlas Project to derive an accurate molecular prognostic classifier. Unsupervised analysis of the 82 genes that were most closely associated with recurrence after surgery enabled the identification of three unique molecular subtypes. One subtype had a high recurrence rate, an immunosuppressed microenvironment, and enrichment of the EZH2-HOTAIR pathway. Two other unique molecular subtypes with a lower rate of recurrence were identified, including one subtype with a paucity of BRAFV600E mutations and a high rate of RAS mutations. The genomic risk classifier, in addition to tumor size and lymph node status, enabled effective prognostication that outperformed the American Thyroid Association clinical risk stratification. The genomic classifier we derived can potentially be applied preoperatively to direct clinical decision-making. Distinct biological features of molecular subtypes also have implications regarding sensitivity to radioactive iodine, EZH2 inhibitors, and immune checkpoint inhibitors.

NK2 homeobox gene cluster: Functions and roles in human diseases

NK2 genes (NKX2 gene cluster in humans) encode for homeodomain-containing transcription factors that are conserved along the phylogeny. According to the most detailed classifications, vertebrate NKX2 genes are classified into two distinct families, NK2.1 and NK2.2. The former is constituted by NKX2-1 and NKX2-4 genes, which are homologous to the Drosophila scro gene; the latter includes NKX2-2 and NKX2-8 genes, which are homologous to the Drosophila vnd gene. Conservation of these genes is not only related to molecular structure and expression, but also to biological functions. In Drosophila and vertebrates, NK2 genes share roles in the development of ventral regions of the central nervous system. In vertebrates, NKX2 genes have a relevant role in the development of several other organs such as the thyroid, lung, and pancreas. Loss-of-function mutations in NKX2-1 and NKX2-2 are the monogenic cause of the brain-lung-thyroid syndrome and neonatal diabetes, respectively. Alterations in NKX2-4 and NKX2-8 genes may play a role in multifactorial diseases, autism spectrum disorder, and neural tube defects, respectively. NKX2-1, NKX2-2, and NKX2-8 are expressed in various cancer types as either oncogenes or tumor suppressor genes. Several data indicate that evaluation of their expression in tumors has diagnostic and/or prognostic value.

Anaplastic Transformation of Follicular Thyroid Carcinoma in Pulmonary Metastasis With Gradually Progressive Intra-tumoral Cavitation: A Case Report

Anaplastic transformation of differentiated thyroid cancer is rare but clinically important because of the dismal prognosis after anaplastic transformation. Therefore, cases and findings of anaplastic transformation must be accumulated, which could ultimately lead to an earlier diagnosis and an improved prognosis. Here, we present a case of anaplastic transformation of follicular thyroid carcinoma (FTC) in a pulmonary metastatic lesion associated with gradually progressive tumor cavitation. The patient with FTC was diagnosed with multiple lung metastases three years after surgery for the primary tumor and metastatic neck lymph nodes. Annual treatment with radioactive iodine resulted in disease stability for 10 years. However, one lung metastasis in the left lower lobe gradually enlarged and was associated with intra-tumoral cavitation. The growing lung nodule was resected and pathologically diagnosed as an anaplastic transformation of FTC. Fourteen months after diagnosis, the patient died of pneumothorax caused by pleural dissemination despite multiple treatment interventions. This case highlights pulmonary metastasis with progressive cavitary lesions as a potential early sign of the anaplastic transformation of differentiated thyroid cancer.

Primary Versus Secondary Anaplastic Thyroid Carcinoma: Perspectives from Multi-institutional and Population-Level Data

Primary (or de novo) anaplastic thyroid carcinoma (ATC) is ATC without pre-existing history of differentiated thyroid carcinoma (DTC) and no co-existing DTC foci at the time of diagnosis. Secondary ATC is diagnosed if the patient had a history of DTC or co-existing DTC components at time of diagnosis. This study aimed to investigate the incidence, clinical presentations, outcomes, and genetic backgrounds of primary versus secondary ATCs. We searched for ATCs in our institutional databases and the Surveillance, Epidemiology, and End Result (SEER) database. We also performed a systematic review and meta-analysis to analyze the genetic alterations of primary and secondary ATCs. From our multi-institutional database, 22 primary and 23 secondary ATCs were retrieved. We also identified 620 and 24 primary and secondary ATCs in the SEER database, respectively. Compared to primary ATCs, secondary ATCs were not statistically different in terms of demographic, clinical manifestations, and patient survival. The only clinical discrepancy between the two groups was a significantly larger tumor diameter of the primary ATCs. The prevalence of TERT promoter, PIK3CA, and TP53 mutations was comparable between the two subtypes. In comparison to primary ATCs, however, BRAF mutations were more prevalent (OR = 4.70; 95% CI = 2.84-7.78) whereas RAS mutations were less frequent (OR = 0.43; 95% CI = 0.21-0.85) in secondary tumors. In summary, our results indicated that de novo and secondary ATCs might share many potential developmental steps, but there are other factors that suggest distinct developmental pathways.

How to identify indolent thyroid tumors unlikely to recur and cause cancer death immediately after surgery-Risk stratification of papillary thyroid carcinoma in young patients

Current histopathological diagnosis methods cannot distinguish the two types of thyroid carcinoma: clinically significant carcinomas with a potential risk of recurrence, metastasis, and cancer death, and clinically insignificant carcinomas with a slow growth rate. Both thyroid tumors are diagnosed as "carcinoma" in current pathology practice. The clinician usually recommends surgery to the patient and the patient often accepts it because of cancer terminology. The treatment for these clinically insignificant carcinomas does not benefit the patient and negatively impacts society. The author proposed risk stratification of thyroid tumors using the growth rate (Ki-67 labeling index), which accurately differentiates four prognostically relevant risk groups based on the Ki-67 labeling index, ≥30%, ≥10 and <30%, >5 and <10%, and ≤5%. Indolent thyroid tumors with an excellent prognosis have the following four features: young age, early-stage (T1-2 M0), curatively treated, and low proliferation index (Ki-67 labeling index of ≤5%), and are unlikely to recur, metastasize, or cause cancer death. Accurate identification of these indolent tumors helps clinicians select more conservative treatments to avoid unnecessary aggressive (total thyroidectomy followed by radio-active iodine) treatments. Clinicians can alleviate the fears of patients by confirming these four features, including the low proliferation rate, in a pathology report immediately after surgery when patients are most concerned.

Thyroid disorders in elderly: A comprehensive review

The approach to management of thyroid disorders in the elderly differs from that for younger individuals: it considers frailty of the population, coexisting medical illness and medications, clearance rate of medications and drug-drug interactions along with target organ sensitivity to the treatment. We present a comprehensive review of literature for the clinical presentation, pathophysiology, diagnostic evaluation, and management of thyroid disorders in the elderly.

Correlation of the Expression of BRAF V600E Mutation With Various Phenotypic Expressions of Thyroid Neoplasms

Aims We aimed to assess the incidence of the BRAF V600E mutation in thyroid neoplasms at a tertiary care center and its association with various phenotypic features. Methods and material We included all cases diagnosed as thyroid neoplasm in the past decade at the Department of Pathology of our institute and obtained their clinical details from the medical records department of the institute after obtaining permission from the authorities and due International Human Epigenome Consortium clearance. We included data on age, sex, clinical presentation, hormone status, and T and N status of the malignant neoplasms. Hematoxylin and eosin (H&E) slides of all cases were evaluated for the type of neoplasm, nuclear features, invasion into the capsule and vascular spaces, extrathyroidal extension, lymph node metastases, mitoses, necrosis, and presence/absence of amyloid. Paraffin blocks of sections with high tumor density and less normal tissue were chosen for evaluation after H&E staining. The slides showing tumors with large areas of hemorrhage, cystic change, or necrosis were excluded. Two primers were used to amplify a 339-bp fragment containing the V600E mutation in exon 15 of BRAF. Tissues were prepared from formalin-fixed paraffin-embedded (FFPE) blocks, and DNA was isolated using a standard protocol BRAF NF and BRAF NR Primer Standardized Protocol For FFPE Tissue DNA. Percentages and tables have been used for data presentation. Results Among 47 identified cases, 14 were positive for the BRAF V600E mutation and had papillary carcinoma (n = 9) or follicular neoplasms (n = 5; follicular adenoma, n = 3; follicular carcinoma, n = 2). In the BRAF-positive papillary carcinomas, five cases were aged 20-30 years, eight were female, eight (88.88%) were euthyroid, and one was hypothyroid. Furthermore, 55.55% (5/9 cases) of BRAF-positive cases were stage I, 33.3% (3/9 cases) were stage II, and 0.02% (1/9 cases) were stage III. Conclusions In our cohort, 31% of cases of papillary thyroid carcinoma (PTC) and 18.72% of follicular neoplasms expressed the BRAF V600E mutation. BRAF V600E mutation-positive papillary thyroid carcinomas consistently showed all characteristic nuclear features, such as nuclear crowding, overlapping, and grooves. Considering the greater prevalence in the younger age group, the importance of mutation surveillance in PTCs for a total thyroidectomy may be warranted in mutation-positive patients.

Oncocytic Papillary Thyroid Carcinoma and Oncocytic Poorly Differentiated Thyroid Carcinoma: Clinical Features, Uptake, and Response to Radioactive Iodine Therapy, and Outcome

OBJECTIVE

The main objective of this study was to review the clinicopathologic characteristics and outcome of patients with oncocytic papillary thyroid carcinoma (PTC) and oncocytic poorly differentiated thyroid carcinoma (PDTC). The secondary objective was to evaluate the prevalence and outcomes of RAI use in this population.

METHODS

Patients with oncocytic PTC and PDTC who were treated at a quaternary cancer centre between 2002 and 2017 were retrospectively identified from an institutional database. All patients had an expert pathology review to ensure consistent reporting and definition. The cumulative incidence function was used to analyse locoregional failure (LRF) and distant metastasis (DM) rates. Univariable analysis (UVA) was used to assess clinical predictors of outcome.

RESULTS

In total, 263 patients were included (PTC [n=218], PDTC [n=45]) with a median follow up of 4.4 years (range: 0 = 26.7 years). Patients with oncocytic PTC had a 5/10-year incidence of LRF and DM, respectively, of 2.7%/5.6% and 3.4%/4.5%. On UVA, there was an increased risk of DM in PTC tumors with widely invasive growth (HR 17.1; p<0.001), extra-thyroidal extension (HR 24.95; p<0.001), angioinvasion (HR 32.58; p=0.002), focal dedifferentiation (HR 19.57, p<0.001), and focal hobnail cell change (HR 8.67, p=0.042). There was additionally an increased risk of DM seen in male PTC patients (HR 5.5, p=0.03).The use of RAI was more common in patients with larger tumors, angioinvasion, and widely invasive disease. RAI was also used in the management of DM and 43% of patients with oncocytic PTC had RAI-avid metastatic disease. Patients with oncocytic PDTC had a higher rate of 5/10-year incidence of LRF and DM (21.4%/45.4%; 11.4%/40.4%, respectively). Patients with extra-thyroidal extension had an increased risk of DM (HR 5.52, p=0.023) as did those with angioinvasion. Of the patients with oncocytic PDTC who received RAI for the treatment of DM, 40% had RAI-avid disease.

CONCLUSION

We present a large homogenous cohort of patients with oncocytic PTC and PDTC, with consistent pathologic reporting and definition. Patients with oncocytic PTC have excellent clinical outcomes and similar risk factors for recurrence as their non-oncocytic counterparts (angioinvasion, large tumor size, extra-thyroidal extension, and focal dedifferentiation). Compared with oncocytic PTCs, the adverse biology of oncocytic PDTCs is supported with increased frequency of DM and lower uptake of RAI.