Hereditary and familial thyroid tumours

Thyroid nodules with DICER1 mutation or PTEN alteration: A comparative cytologic, clinical, and molecular study of 117 FNA cases

BACKGROUND

DICER1 mutations and PTEN alterations are increasingly detected by thyroid fine-needle aspiration (FNA). Both are associated with nodular thyroid disease and cancer. The authors analyzed a large comparative thyroid FNA cohort with DICER1 mutation or PTEN alteration.

METHODS

A total of 117 thyroid FNAs with DICER1 or PTEN alterations were retrieved from the databases of two academic medical institutions. Demographic, clinical, and radiologic data were collected; FNA slides were analyzed for 29 cytomorphologic features.

RESULTS

Of 117 thyroid FNAs, 36 (30.8%) had DICER1 mutation and 81 (69.2%) showed PTEN alteration. The DICER1 cohort had 33 (91.7%) females and three (8.3%) males (mean, 40.9 years); 61.8% had multinodular disease. FNAs were classified as atypia of undetermined significance (AUS), 23 (63.9%); follicular neoplasm (FN), 12 (33.3%); and malignant, 1 (2.8%). The PTEN subgroup had 66 (81.5%) females and 15 (18.5%) males (mean, 55.2 years) with increased multinodular disease (93.8%, p = .0016). PTEN FNAs had greater cytologic diversity: non-diagnostic, 2 (2.5%); benign, 5 (6.2%); AUS, 44 (54.3%); FN, 24 (29.6%); and malignant, 6 (7.4%). Both DICER1 and PTEN cases showed a range of resected tumor subtypes. The DICER1 cohort included thyroblastoma, and the PTEN group included anaplastic carcinoma. The cytomorphology of DICER1 and PTEN cases showed overlapping features, especially microfollicular patterns. Minor cytomorphologic differences included papillary patterns in DICER1 (p = .039), and oncocytic changes (p < .0001) in PTEN.

CONCLUSIONS

DICER1 and PTEN FNAs reveal many cytologic similarities. DICER1 patients are younger, and PTEN patients had multinodular disease. Awareness of these genetic cohorts can identify patients at risk for thyroid cancer.

CHEK2 germline variants identified in familial nonmedullary thyroid cancer lead to impaired protein structure and function

Approximately 5 to 15% of nonmedullary thyroid cancers (NMTC) present in a familial form (familial nonmedullary thyroid cancers [FNMTC]). The genetic basis of FNMTC remains largely unknown, representing a limitation for diagnostic and clinical management. Recently, germline mutations in DNA repair-related genes have been described in cases with thyroid cancer (TC), suggesting a role in FNMTC etiology. Here, two FNMTC families were studied, each with two members affected with TC. Ninety-four hereditary cancer predisposition genes were analyzed through next-generation sequencing, revealing two germline CHEK2 missense variants (c.962A > C, p.E321A and c.470T > C, p.I157T), which segregated with TC in each FNMTC family. p.E321A, located in the CHK2 protein kinase domain, is a rare variant, previously unreported in the literature. Conversely, p.I157T, located in CHK2 forkhead-associated domain, has been extensively described, having conflicting interpretations of pathogenicity. CHK2 proteins (WT and variants) were characterized using biophysical methods, molecular dynamics simulations, and immunohistochemistry. Overall, biophysical characterization of these CHK2 variants showed that they have compromised structural and conformational stability and impaired kinase activity, compared to the WT protein. CHK2 appears to aggregate into amyloid-like fibrils in vitro, which opens future perspectives toward positioning CHK2 in cancer pathophysiology. CHK2 variants exhibited higher propensity for this conformational change, also displaying higher expression in thyroid tumors. The present findings support the utility of complementary biophysical and in silico approaches toward understanding the impact of genetic variants in protein structure and function, improving the current knowledge on CHEK2 variants' role in FNMTC genetic basis, with prospective clinical translation.

Investigating USP42 Mutation as Underlying Cause of Familial Non-Medullary Thyroid Carcinoma

In a family with Familial Non-Medullary Thyroid Carcinoma (FNMTC), our investigation using Whole-Exome Sequencing (WES) uncovered a novel germline USP42 mutation [p.(Gly486Arg)]. USP42 is known for regulating p53, cell cycle arrest, and apoptosis, and for being reported as overexpressed in breast and gastric cancer patients. Recently, a USP13 missense mutation was described in FNMTC, suggesting a potential involvement in thyroid cancer. Aiming to explore the USP42 mutation as an underlying cause of FNMTC, our team validated the mutation in blood and tissue samples from the family. Using immunohistochemistry, the expression of USP42, Caspase-3, and p53 was assessed. The USP42 gene was silenced in human thyroid Nthy-Ori 3-1 cells using siRNAs. Subsequently, expression, viability, and morphological assays were conducted. p53, Cyclin D1, p21, and p27 proteins were evaluated by Western blot. USP42 protein was confirmed in all family members and was found to be overexpressed in tumor samples, along with an increased expression of p53 and cleaved Caspase-3. siRNA-mediated USP42 downregulation in Nthy-Ori 3-1 cells resulted in reduced cell viability, morphological changes, and modifications in cell cycle-related proteins. Our results suggest a pivotal role of USP42 mutation in thyroid cell biology, and this finding indicates that USP42 may serve as a new putative target in FNMTC.

Expanding Our Knowledge of DICER1 Gene Alterations and Their Role in Thyroid Diseases

Mutations in DICER1, a gene involved in RNA interference, have been associated with a wide range of multi-organ neoplastic and non-neoplastic conditions. Historically known for its association with pleuropulmonary blastoma, DICER1 syndrome has received more attention due to the association with newly discovered diseases and tumors. Recent studies evaluating DICER1 mutations and DICER1-driven thyroid disease in both pediatric and adult thyroid nodules revealed thyroid disease as the most common manifestation of DICER1 mutations. This study undertakes a comprehensive investigation into DICER1 mutations, focusing on their role in thyroid diseases. Specific attention was given to thyroid follicular nodular disease and differentiated thyroid carcinomas in infancy as highly indicative of germline DICER1 mutation or DICER1 syndrome. Additionally, poorly differentiated thyroid carcinoma and thyroblastoma were identified as potential indicators of somatic DICER1 mutations. Recognizing these manifestations should prompt clinicians to expedite genetic evaluation for this neoplastic syndrome and classify these patients as high risk for additional multi-organ malignancies. This study comprehensively synthesizes the current knowledge surrounding this genetically associated entity, providing intricate details on histologic findings to facilitate its diagnosis.

Cancer Predisposition Syndromes and Thyroid Cancer: Keys for a Short Two-Way Street

Cancer predisposition syndromes are entities determined especially by germinal pathogenic variants, with most of them autosomal dominantly inherited. The risk of a form of cancer is variable throughout life and affects various organs, including the thyroid. Knowing the heterogeneous clinical picture and the existing genotype-phenotype correlations in some forms of thyroid cancer associated with these syndromes is important for adequate and early management of patients and families. This review synthesizes the current knowledge on genes and proteins involved in cancer predisposition syndromes with thyroid cancer and the phenomena of heterogeneity (locus, allelic, mutational, and clinical).

FAMILIAL NON-MEDULLARY THYROID CARCINOMA

BACKGROUND

Familial non-medullary thyroid carcinoma (FNMTC) is defined as cancer developing in two or more first-degree relatives if predisposing factors, for example, radiation, are absent. The disease can be either syndromic, when it is a component of complex genetic syndromes, or non-syndromic (95% cases). The genetic basis of non-syndromic FNMTC is unknown; the clinical behavior of tumorsis unclear and, at times, contradictory.

AIM

To analyze clinical manifestations of FNMTC and compare them with the data for sporadic papillary thyroid carcinomas in patients of the same age groups.

MATERIALS AND METHODS

We examined 22 patients (a "parents" group and a "children" group) suffering from the non-syndromic FNMTC. For comparison, two groups of sporadic papillary carcinomas patients of the same age were drawn up("adult" and "young"). We analyzed tumor size and frequency of the distributionby the categoryof TNM system, invasiveness, multifocality, metastases to lymph nodes, type and extent of surgical and radioiodine treatment, and prognosis according to the MACIS criterion.

RESULTS

Whether sporadic or familial, the tumor size, metastatic potential, and invasive potential are higher in young people, asalready known. There was no significant difference between the "parents" and "adult" groups of patients in terms of tumor parameters. One exception was the higher frequency of multifocal tumors in the FNMTC patients. Meanwhile, compared to the "young" sporadic papillary carcinomas patients, the FNMTC "children" had a higher frequency of T2 tumors, metastasizing (N1a-N1ab), and multifocal tumors, but a lower frequency of carcinomas with intrathyroidal invasions.In the FNMTC "children" compared to FNMTC "parents" was a higher frequency of T2 tumors, metastasizing carcinomas, and tumors with capsular invasion.

CONCLUSION

FNMTC carcinomas are more aggressive than sporadic ones, especially in patients who are first-degree relatives in a family with parents already diagnosed with the disease.

The Classic, the Trendy, and the Refashioned: A Primer for Pathologists on What Is New in Familial Endocrine Tumor Syndromes

Familial endocrine tumor syndromes are continuously expanding owing to the growing role of genetic testing in routine clinical practice. Pathologists are usually the first on the clinical team to encounter these syndromes at their initial presentation; thus, recognizing them is becoming more pivotal in routine pathology practice to help in properly planning management and further family testing. Our increasing knowledge about them is reflected in the newer syndromes included in the new World Health Organization classification and in the evolving discovery of new endocrine tumors and new familial associations. In many of these syndromes, the clinical features and co-occurrence of multiple neoplasia are the only clues (multiple endocrine neoplasia syndromes). In other syndromes, specific morphologic findings (pituitary blastoma and DICER1 syndrome, cribriform morular thyroid carcinoma, and AFP syndrome) and available ancillary studies (SDHB in SDH-deficient tumor syndromes) can aid pathologists. The aim of this review is to provide a primer on recent updates on familial endocrine tumor syndromes and related tumors, focusing on recent classification changes or tumor syndromes where a clearer role for pathologists is at play.

Update from the 2022 World Health Organization Classification of Thyroid Tumors: A Standardized Diagnostic Approach

The fifth edition of the World Health Organization (WHO) histologic classification of thyroid neoplasms released in 2022 includes newly recognized tumor types, subtypes, and a grading system. Follicular cell-derived neoplasms are categorized into three families (classes): benign tumors, low-risk neoplasms, and malignant neoplasms. The terms "follicular nodular disease" and "differentiated high-grade thyroid carcinoma" are introduced to account for multifocal hyperplastic/neoplastic lesions and differentiated thyroid carcinomas with high-grade features, respectively. The term "Hürthle cells" is replaced with "oncocytic cells." Invasive encapsulated follicular and cribriform morular variants of papillary thyroid carcinoma (PTC) are now redefined as distinct tumor types, given their different genetic alterations and clinicopathologic characteristics from other PTC subtypes. The term "variant" to describe a subclass of tumor has been replaced with the term "subtype." Instead, the term "variant" is reserved to describe genetic alterations. A histologic grading system based on the mitotic count, necrosis, and/or the Ki67 index is used to identify high-grade follicular-cell derived carcinomas and medullary thyroid carcinomas. The 2022 WHO classification introduces the following new categories: "salivary gland-type carcinomas of the thyroid" and "thyroid tumors of uncertain histogenesis." This review summarizes the major changes in the 2022 WHO classification and their clinical relevance.

Thyroid and renal cancers: A bidirectional association

There is a deep interrelation between the thyroid gland and the kidney parenchyma, with dysfunction of the first leading to significant changes in renal metabolism and vice versa. Given the recognition of cancer as a systemic disease, the raise of thyroid tumors and the common association of several malignancies, such as breast cancer, prostate cancer, colorectal cancer, and other, with an increased risk of kidney disease, public health alert for these conditions is warranted. A systematic review of the current evidence on the bidirectional relationship between thyroid and renal cancers was conducted including 18 studies, highlighting patient’s characteristics, histology, time for secondary malignancy to develop from the first diagnosis, treatment, and follow-up. A total of 776 patients were identified; median age was 64 years (range: 7–76 years). Obesity and family history were identified as the most common risk factors, and genetic susceptibility was suggested with a potential strong association with Cowden syndrome. Controversy on chemo and radiotherapy effects was found, as not all patients were previously exposed to these treatments. Men were more likely to develop kidney cancer after a primary thyroid malignancy, with 423/776 (54%) experiencing renal disease secondarily. Median time after the first malignancy was 5.2 years (range: 0–20 years). With the advancement of current oncological therapy, the prognosis for thyroid cancer patients has improved, although there has been a corresponding rise in the incidence of multiple secondary malignancy within the same population, particularly concerning the kidney. Surgery can achieve disease-free survival, if surveillance follow-up allows for an early localized form, where radical treatment is recommended.

Papillary Thyroid Carcinoma: Current Position in Epidemiology, Genomics, and Classification

Papillary thyroid carcinoma is the most common type of thyroid malignancy both in adults and pediatric population. Since the 1980s, there are changes in criteria in labelling thyroid lesions as "papillary thyroid carcinomas." Radiation exposure is a well-established risk factor for papillary thyroid carcinoma. Other environmental risk factors include dietary iodine, obesity, hormones, and environmental pollutants. Papillary thyroid carcinomas could occur in familial settings, and 5% of these familial cases have well-studied driver germline mutations. In sporadic papillary thyroid carcinoma, BRAF mutation is common and is associated with clinicopathologic and prognostic markers. The mutation could aid in the clinical diagnosis of papillary thyroid carcinoma. Globally, thyroid cancer is among the top ten commonest cancer in females. In both adult and pediatric populations, there are variations of prevalence of thyroid cancer and rising incidence rates of thyroid cancer worldwide. The increase of thyroid cancer incidence was almost entirely due to the increase of papillary thyroid carcinoma. The reasons behind the increase are complex, multifactorial, and incompletely understood. The most obvious reasons are increased use of diagnostic entities, change in classification of thyroid neoplasms, as well as factors such as obesity, environmental risk factors, and radiation. The prognosis of the patients with papillary thyroid carcinoma is generally good after treatment. Nevertheless, cancer recurrence and comorbidity of second primary cancer may occur, and it is important to have awareness of the clinical, pathological, and molecular parameters of papillary thyroid carcinoma.

Genetic susceptibility to hereditary non-medullary thyroid cancer

Non-medullary thyroid cancer (NMTC) is the most common type of thyroid cancer. With the increasing incidence of NMTC in recent years, the familial form of the disease has also become more common than previously reported, accounting for 5-15% of NMTC cases. Familial NMTC is further classified as non-syndromic and the less common syndromic FNMTC. Although syndromic NMTC has well-known genetic risk factors, the gene(s) responsible for the vast majority of non-syndromic FNMTC cases are yet to be identified. To date, several candidate genes have been identified as susceptibility genes in hereditary NMTC. This review summarizes genetic predisposition to non-medullary thyroid cancer and expands on the role of genetic variants in thyroid cancer tumorigenesis and the level of penetrance of NMTC-susceptibility genes.

Overview of the 2022 WHO Classification of Thyroid Neoplasms

This review summarizes the changes in the 5th edition of the WHO Classification of Endocrine and Neuroendocrine Tumors that relate to the thyroid gland. The new classification has divided thyroid tumors into several new categories that allow for a clearer understanding of the cell of origin, pathologic features (cytopathology and histopathology), molecular classification, and biological behavior. Follicular cell-derived tumors constitute the majority of thyroid neoplasms. In this new classification, they are divided into benign, low-risk, and malignant neoplasms. Benign tumors include not only follicular adenoma but also variants of adenoma that are of diagnostic and clinical significance, including the ones with papillary architecture, which are often hyperfunctional and oncocytic adenomas. For the first time, there is a detailed account of the multifocal hyperplastic/neoplastic lesions that commonly occur in the clinical setting of multinodular goiter; the term thyroid follicular nodular disease (FND) achieved consensus as the best to describe this enigmatic entity. Low-risk follicular cell-derived neoplasms include non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP), thyroid tumors of uncertain malignant potential, and hyalinizing trabecular tumor. Malignant follicular cell-derived neoplasms are stratified based on molecular profiles and aggressiveness. Papillary thyroid carcinomas (PTCs), with many morphological subtypes, represent the BRAF-like malignancies, whereas invasive encapsulated follicular variant PTC and follicular thyroid carcinoma represent the RAS-like malignancies. This new classification requires detailed subtyping of papillary microcarcinomas similar to their counterparts that exceed 1.0 cm and recommends not designating them as a subtype of PTC. The criteria of the tall cell subtype of PTC have been revisited. Cribriform-morular thyroid carcinoma is no longer classified as a subtype of PTC. The term "Hürthle cell" is discouraged, since it is a misnomer. Oncocytic carcinoma is discussed as a distinct entity with the clear recognition that it refers to oncocytic follicular cell-derived neoplasms (composed of > 75% oncocytic cells) that lack characteristic nuclear features of PTC (those would be oncocytic PTCs) and high-grade features (necrosis and ≥ 5 mitoses per 2 mm²). High-grade follicular cell-derived malignancies now include both the traditional poorly differentiated carcinoma as well as high-grade differentiated thyroid carcinomas, since both are characterized by increased mitotic activity and tumor necrosis without anaplastic histology and clinically behave in a similar manner. Anaplastic thyroid carcinoma remains the most undifferentiated form; squamous cell carcinoma of the thyroid is now considered as a subtype of anaplastic carcinoma. Medullary thyroid carcinomas derived from thyroid C cells retain their distinct section, and there is a separate section for mixed tumors composed of both C cells and any follicular cell-derived malignancy. A grading system for medullary thyroid carcinomas is also introduced based on mitotic count, tumor necrosis, and Ki67 labeling index. A number of unusual neoplasms that occur in the thyroid have been placed into new sections based on their cytogenesis. Mucoepidermoid carcinoma and secretory carcinoma of the salivary gland type are now included in one section classified as "salivary gland-type carcinomas of the thyroid." Thymomas, thymic carcinomas and spindle epithelial tumor with thymus-like elements are classified as "thymic tumors within the thyroid." There remain several tumors whose cell lineage is unclear, and they are listed as such; these include sclerosing mucoepidermoid carcinoma with eosinophilia and cribriform-morular thyroid carcinoma. Another important addition is thyroblastoma, an unusual embryonal tumor associated with DICER1 mutations. As in all the WHO books in the 5th edition, mesenchymal and stromal tumors, hematolymphoid neoplasms, germ cell tumors, and metastatic malignancies are discussed separately. The current classification also emphasizes the value of biomarkers that may aid diagnosis and provide prognostic information.

Overview of the 2022 WHO Classification of Familial Endocrine Tumor Syndromes

This review of the familial tumor syndromes involving the endocrine organs is focused on discussing the main updates on the upcoming fifth edition of the WHO Classification of Endocrine and Neuroendocrine Tumors. This review emphasizes updates on histopathological and molecular genetics aspects of the most important syndromes involving the endocrine organs. We describe the newly defined Familial Cancer Syndromes as MAFA-related, MEN4, and MEN5 as well as the newly reported pathological findings in DICER1 syndrome. We also describe the updates done at the new WHO on the syndromic and non-syndromic familial thyroid diseases. We emphasize the problem of diagnostic criteria, mention the new genes that are possibly involved in this group, and at the same time, touching upon the role of some immunohistochemical studies that could support the diagnosis of some of these conditions. As pathologists play an important role in identifying tumors within a familial cancer syndrome, we highlight the most important clues for raising the suspicious of a syndrome. Finally, we highlight the challenges in defining these entities as well as determining their clinical outcome in comparison with sporadic tumors. Instead of the usual subject review, we present the highlights of the updates on familial cancer syndromes by answering select questions relevant to practicing pathologists.

Germline pathogenic variants in cancer risk genes among patients with thyroid cancer and suspected predisposition

Purpose

Multigene panels allow simultaneous testing of genes involved in cancer predisposition. Thyroid cancer (TCa) is a component tumor of several cancer predisposition syndromes, but the complete landscape of germline variants predisposing to TCa remains to be determined.

Methods

Clinical information and genetic test results were reviewed from over 170,000 individuals who had multigene panel testing for hereditary cancer at a single diagnostic laboratory. Germline pathogenic and likely pathogenic variants (“pathogenic variants”) were examined among individuals with TCa. A cohort with breast cancer (BCa) was examined to serve as a comparison group and to determine the added contribution of TCa to the ascertainment of genetic risk.

Results

Of 3134 individuals with TCa, 291 (9.3%) were found to have one or more pathogenic variant(s). Among 904 individuals with TCa alone, 7.5% had one or more pathogenic variant(s), similar to those with BCa alone (8.4%). In all groups, CHEK2 was the gene with the highest number of pathogenic variants identified, with a significantly increased frequency among individuals with a history of both thyroid and BCa compared to BCa alone.

Conclusions

A high prevalence of germline pathogenic variants was observed among individuals with TCa referred for hereditary cancer genetic testing, even in the absence of other cancer diagnoses. These data suggest that TCa may be an under‐recognized component of cancer predisposition syndromes.

New Perspectives on the Recurrent Monoallelic Germline Mutations of DNA Repair and Checkpoint Genes and Clinical Variability

Background: Inherited cancers account for ∼10% of cancer cases. Many hereditary cancers are associated with mutations in DNA repair and checkpoint genes making their clinical surveillance important. Methods: We screened 900 patients using a comprehensive cancer gene panel with the following diagnoses: familial (n = 537, 59.6%), colorectal (n = 117, 13%), breast-ovarian (n = 215, 23.8%), endometrium (n = 12, 1.3%), gastric (n = 11, 1.2%), and thyroid (n = 8, 0.8%). Results: The most commonly mutated genes identified were ATM, MSH6, MUTYH, CHEK2, APC, MLH1, RAD50, PALB2, MSH2, CDH1, and PMS2. The most prevalent heterozygous was MUTYH: c.884C>T(P295L), which was predominant in the breast-ovarian group. Notably, the MUTYH, MSH6, and MSH2 variants showed a higher incidence of extracolonic malignancy. Among the DNA mismatch repair (MMR) genes, MSH6 mutations were the most common, followed by mutations in MLH1, MSH2, PMS2, and EPCAM. Conclusion: These findings offer a new perspective and suggest that, beyond ATM, CHEK2, and PALB2, patients with germline monoallelic mutations in MUTYH, MSH6, APC, CDH1, MHS2, and PMS2 may present with a hereditary breast-ovarian cancer phenotype. Continued developments in assessing and researching new variants of known cancer candidate genes will play an important role in improving individual risk prediction, therapy, and prognosis for familial cancers.

DICER1 tumor predisposition syndrome: an evolving story initiated with the pleuropulmonary blastoma

DICER1 syndrome (OMIM 606241, 601200) is a rare autosomal dominant familial tumor predisposition disorder with a heterozygous DICER1 germline mutation. The most common tumor seen clinically is the pleuropulmonary blastoma (PPB), a lung neoplasm of early childhood which is classified on its morphologic features into four types (IR, I, II and III) with tumor progression over time within the first 4-5 years of life from the prognostically favorable cystic type I to the unfavorable solid type III. Following the initial report of PPB, its association with other cystic neoplasms was demonstrated in family studies. The detection of the germline mutation in DICER1 provided the opportunity to identify and continue to recognize a number seemingly unrelated extrapulmonary neoplasms: Sertoli-Leydig cell tumor, gynandroblastoma, embryonal rhabdomyosarcomas of the cervix and other sites, multinodular goiter, differentiated and poorly differentiated thyroid carcinoma, cervical-thyroid teratoma, cystic nephroma-anaplastic sarcoma of kidney, nasal chondromesenchymal hamartoma, intestinal juvenile-like hamartomatous polyp, ciliary body medulloepithelioma, pituitary blastoma, pineoblastoma, primary central nervous system sarcoma, embryonal tumor with multilayered rosettes-like cerebellar tumor, PPB-like peritoneal sarcoma, DICER1-associated presacral malignant teratoid neoplasm and other non-neoplastic associations. Each of these neoplasms is characterized by a second somatic mutation in DICER1. In this review, we have summarized the salient clinicopathologic aspects of these tumors whose histopathologic features have several overlapping morphologic attributes particularly the primitive mesenchyme often with rhabdomyoblastic and chondroid differentiation and an uncommitted spindle cell pattern. Several of these tumors have an initial cystic stage from which there is progression to a high grade, complex patterned neoplasm. These pathologic findings in the appropriate clinical setting should serve to alert the pathologist to the possibility of a DICER1-associated neoplasm and initiate appropriate testing on the neoplasm and to alert the clinician about the concern for a DICER1 mutation.

Susceptibility Genes and Chromosomal Regions Associated With Non-Syndromic Familial Non-Medullary Thyroid Carcinoma: Some Pathogenetic and Diagnostic Keys

Thyroid cancer is the malignant tumor that is increasing most rapidly in the world, mainly at the expense of sporadic papillary thyroid carcinoma. The somatic alterations involved in the pathogenesis of sporadic follicular cell derived tumors are well recognized, while the predisposing alterations implicated in hereditary follicular tumors are less well known. Since the genetic background of syndromic familial non-medullary carcinoma has been well established, here we review the pathogenesis of non-syndromic familial non-medullary carcinoma emphasizing those aspects that may be useful in clinical and pathological diagnosis. Non-syndromic familial non-medullary carcinoma has a complex and heterogeneous genetic basis involving several genes and loci with a monogenic or polygenic inheritance model. Most cases are papillary thyroid carcinoma (classic and follicular variant), usually accompanied by benign thyroid nodules (follicular thyroid adenoma and/or multinodular goiter). The possible diagnostic and prognostic usefulness of the changes in the expression and/or translocation of various proteins secondary to several mutations reported in this setting requires further confirmation. Given that non-syndromic familial non-medullary carcinoma and sporadic non-medullary thyroid carcinoma share the same morphology and somatic mutations, the same targeted therapies could be used at present, if necessary, until more specific targeted treatments become available.

Comparison Between Clinicopathological Characteristics, BRAF V600E and TERT Promoter Mutation of Familial Non-Medullary Thyroid Carcinomas, and Sporadic Case

Background

It has been debated whether familial non-medullary thyroid carcinoma (FNMTC) is more aggressive and has a worse prognosis than sporadic non-medullary thyroid carcinoma (SNMTC). Our aim was to compare the invasiveness and prognosis of FNMTC and SNMTC by their biological behavior and molecular changes.

Method and Material

Our group mainly compared 106 patients with FNMTC whom have complete clinicopathological data during 2011–2019 in West China Hospital, Sichuan University, and 212 randomly selected cases with SNMTC were included to compare their biological behavior, recurrence and mortality, and molecular expression of BRAF V600E and TERT promoter. At the same time, FNMTC cases were divided into four subgroups, namely, two affected members group, three or more affected members, parent/offspring group, and sibling group, and they were compared with SNMTC separately to analyze the difference in their invasiveness and prognosis.

Results

We found that the mean tumor size of FNMTC (0.96 ± 0.53cm) was smaller than that of SNMTC (1.15 ± 0.72 cm) (p = 0.020), while no significant difference in the incidence of other clinicopathological factors, including bilateral growth, capsular invasion, with thyroid nodular goiter or not, multifocality, lymph node metastasis, extrathyroidal extension, iodine 131 treatments, T stage, and American Joint Committee on Cancer (AJCC) stage, was observed between FNMTC and SNMTC (p > 0.05), between each FNMTC subgroup (p > 0.05), and between each FNMTC subgroup and SNMTC (p > 0.05). There was no significant difference in recurrence, mortality, and BRAF V600E and TERT promoter mutation between FNMTC and SNMTC, among which 50/60 (83.33%) of FNMTC patients had BRAF V600E mutation and 1/32 (3.13%) had TERT promoter mutation, while the mutation rates of SNMTC were 93/108 (86.11%) and 3/64 (4.69%) (p > 0.05).

Conclusion

There was no significant difference in invasiveness and prognosis between FNMTC and SNMTC by biological behavior, patient survival, and molecular level comparison.

Maternal Thyroid Disease and the Risk of Childhood Cancer in the Offspring

Maternal thyroid disease, especially hypothyroidism, affects pregnancy and its outcome. In-utero exposure to autoimmune thyroid disease has been reported to associate with childhood ALL in the offspring. We evaluated the risk of childhood cancer in the offspring following exposure to maternal thyroid disease in a case-control setting using registry data. All patients with their first cancer diagnosis below the age of 20 years were identified from the Finnish Cancer Registry (n = 2037) and matched for sex and birth year at a 1:5 ratio to population controls identified from the Medical Birth Registry (n = 10,185). We collected national information on maternal thyroid disease from the Medical Birth Registry, Care Register for Health Care, Register for Reimbursed Drug Purchases and Register of Special Reimbursements. We used conditional logistic regression to analyze childhood cancer risk in the offspring. The adjusted OR for any childhood cancer was 1.41 (95%, CI 1.00-2.00) comparing the offspring of mothers with hypothyroidism and those with normal thyroid function. The risk of lymphomas was increased (adjusted OR for maternal hypothyroidism 3.66, 95%, CI 1.29-10.38). The results remained stable when mothers with cancer history were excluded from the analyses. Maternal hypothyroidism appears to be associated with an increased risk for childhood lymphoma in the offspring. The association exists even after excluding possible familial cancers.

Papillary Thyroid Cancer Affecting Multiple Family Members: A Case Report and Literature Review of Familial Nonmedullary Thyroid Cancer

Familial nonmedullary thyroid cancer (FNMTC) represents 5–10% of NMTC cases. Many controversies are associated with the FNMTC, namely, the minimum required number of affected family members to define the condition, aggressiveness, prognosis, and treatment and screening recommendations. Moreover, the genetic basis of the FNMTC has not yet been identified. We report a family diagnosed with FNMTC and present a comprehensive literature review of the condition. The index case was a 26-year-old male who was diagnosed with locally advanced papillary thyroid cancer (PTC). Then, his family members became worried and asked for a neck ultrasound. Four of his six siblings, in addition to his father, were diagnosed with PTC. In addition, two of his cousins were diagnosed. The patient underwent total thyroidectomy with bilateral neck dissection, and he received 2 doses of radioactive iodine (100 mCi each). Furthermore, one of his siblings required a second surgery with repeated radioactive iodine therapy. The index case genetic screening and whole-exome sequencing did not show any abnormalities. Future genetic and clinical research should focus on kindred with 3 or more affected individuals for better identification of the FNMTC susceptibility genes and to better guide management and screening recommendations.

Cribriform-Morular Thyroid Carcinoma Is a Distinct Thyroid Malignancy of Uncertain Cytogenesis

Tumors with papillary cribriform and morular architecture were initially considered to be variants of papillary thyroid carcinoma; however, recent observations have challenged this view. In this study, we reviewed the demographical, histopathological, and immunohistochemical features of the largest case series, consisting of 33 tumors. The age at time of pathological diagnosis ranged from 18 to 59 (mean 33) years, and all patients except one were female. Sixteen patients had multifocal and fifteen had unifocal disease. The status of focality was unavailable in two patients. Tumors were well-circumscribed, ranging in size from 0.1 to 8.0 cm. The cribriform component was admixed with morulae in the majority, except seven had a cribriform-predominant architecture and two had predominantly solid growth. Variable degrees of nuclear enlargement, elongation, overlapping, and grooves were seen but florid nuclear convolution, intranuclear pseudoinclusions, and optically clear nuclei due to chromatin margination were not appreciated. There was no or little colloid material within the cribriform spaces. Two solid tumors had high-grade features. Immunohistochemical studies showed beta-catenin nuclear and cytoplasmic positivity in all cases. The cribriform component was positive for TTF1 and negative for thyroglobulin. PAX8 was absent in half of these tumors and focal in the remainder. Morulae were positive for keratin 5 and CD5 and negative for p63, p40, TTF1, and PAX8. Molecular studies revealed germline APC mutations in 12 tumors and were negative in 5 sporadic tumors in a subset of tested tumors. Irrespective of the antibody used in this cohort, all cribriform-morular carcinomas express TTF1; however, PAX8 immunoreactivity is weak, focal or negative, and all tumors lack thyroglobulin reactivity; these findings raise questions about tumor cell origin and may indicate that these are not of thyroid follicular epithelial differentiation. We postulate that morulae may represent divergent thymic/ultimobranchial pouch-related differentiation. Given their unique cytomorphology, immunohistochemical profiles, and genetic features that have little overlap with traditional follicular cell-derived thyroid carcinomas, we propose that these tumors represent a distinct form of thyroid carcinoma unrelated to other neoplasms of thyroid follicular cells.

The Enigmatic Role of TP53 in Germ Cell Tumours: Are We Missing Something?

The cure rate of germ cell tumours (GCTs) has significantly increased from the late 1970s since the introduction of cisplatin-based therapy, which to date remains the milestone for GCTs treatment. The exquisite cisplatin sensitivity has been mainly explained by the over-expression in GCTs of wild-type TP53 protein and the lack of TP53 somatic mutations; however, several other mechanisms seem to be involved, many of which remain still elusive. The findings about the role of TP53 in platinum-sensitivity and resistance, as well as the reported evidence of second cancers (SCs) in GCT patients treated only with surgery, suggesting a spectrum of cancer predisposing syndromes, highlight the need for a deepened understanding of the role of TP53 in GCTs. In the following report we explore the complex role of TP53 in GCTs cisplatin-sensitivity and resistance mechanisms, passing through several recent genomic studies, as well as its role in GCT patients with SCs, going through our experience of Center of reference for both GCTs and cancer predisposing syndromes.

Association of Parental Consanguinity With Papillary Thyroid Carcinoma: A Case-Control Study

CONTEXT

Papillary thyroid carcinoma (PTC) is the most common type of nonmedullary thyroid carcinoma. Uncommonly, PTC is associated with multiple genetic alterations and chromosomal abnormalities and displays familial patterns of inheritance. Parental consanguinity increases susceptibility to many genetic disorders.

OBJECTIVE

This work aimed to investigate the association of parental consanguinity with PTC.

METHODS

This case-control study of PTC patients compared with healthy controls took place in a tertiary referral hospital. We recruited 200 PTC patients who were managed at the endocrinology outpatient clinics of the Jordan University Hospital, and we recruited 515 healthy controls from a nonclinical setting. We interviewed all participants and collected sociodemographic data. We reviewed the family pedigrees of each participant four generations back and excluded any participant who was related. We established whether the parents of each participant were first cousins, first cousins once removed, second cousins, or unrelated. We then used binary logistic regression to assess the association of parental consanguinity with PTC adjusted for age, sex, smoking status, body mass index, and parental education.

RESULTS

We recruited 715 participants. The numbers of PTC patients and healthy controls were 200 (28.0%) and 515 (72.0%), respectively. The rate of parental consanguinity was 25.5% in PTC patients and 12.2% in healthy controls. Parental consanguinity was significantly associated with PTC (adjusted odds ratio, 2.60; 95% CI, 1.63-4.17; P < .001).

CONCLUSION

Parental consanguinity is a risk factor for PTC. Our findings should be considered during familial risk assessment and genetic counseling, especially in populations with high rates of consanguinity.

A case report of simultaneous medullary and papillary carcinoma of thyroid

Objective. Medullary (MTC) and papillary (PTC) thyroid carcinoma are two different types of thyroid carcinoma with significant differences in origin. Their co-occurrence in a patient is a rare phenomenon. We report a patient with simultaneous presentation of both MTC and PTC. Case presentation. A 62-year-old euthyroid woman with a cervical mass was evaluated, underwent total thyroidectomy, and neck dissection. The examination revealed a MTC large nodule as well as a small nodule of the tall cell variant of PTC, along with the concomitant cervical lymph node metastases. Subsequently, the genetic analysis showed BRAF mutations. Adjuvant treatments including radioiodine and thyroid hormone replacement therapies were performed for the patient. Conclusions. The cooccurrence of MTC and PTC in the same patient is a rare phenomenon. The clinical manifestations and biological behavior of these cancers are completely different. Since the therapeutic strategy and prognosis are very different in these patients, accurate diagnosis of this coexistence is very important.

Genetics of Familial Non-Medullary Thyroid Carcinoma (FNMTC)

Non-medullary thyroid carcinoma (NMTC) is the most frequent endocrine tumor and originates from the follicular epithelial cells of the thyroid. Familial NMTC (FNMTC) has been defined in pedigrees where two or more first-degree relatives of the patient present the disease in absence of other predisposing environmental factors. Compared to sporadic cases, FNMTCs are often multifocal, recurring more frequently and showing an early age at onset with a worse outcome. FNMTC cases show a high degree of genetic heterogeneity, thus impairing the identification of the underlying molecular causes. Over the last two decades, many efforts in identifying the susceptibility genes in large pedigrees were carried out using linkage-based approaches and genome-wide association studies, leading to the identification of susceptibility loci and variants associated with NMTC risk. The introduction of next-generation sequencing technologies has greatly contributed to the elucidation of FNMTC predisposition, leading to the identification of novel candidate variants, shortening the time and cost of gene tests. In this review we report the most significant genes identified for the FNMTC predisposition. Integrating these new molecular findings in the clinical data of patients is fundamental for an early detection and the development of tailored therapies, in order to optimize patient management.

Longer Time to Reach Excellent Response to Treatment in Familial Versus Sporadic Non-medullary Thyroid Cancer (NMTC): A Matched Case-Control Study

BACKGROUND

Familial non-medullary thyroid cancer (NMTC) are supposed to be more aggressive and require more frequent treatment compared to non-familial thyroid cancer.

OBJECTIVES

This matched case-control study aimed to compare the response to treatment between the matched case-control groups of familial and sporadic NMTC.

METHODS

This is a retrospective study in patients with familial NMTC (at least one other first-degree relative involved) who were treated with surgery, followed by radio-iodine therapy (RIT) without consideration of its familial origin. Response to treatment was compared between familial NMTC and age, sex, and TNM stage-matched non-familial NMTC (control group). Response to treatment was assessed one and two years after RIT, and time to excellent response was identified.

RESULTS

Out of 2,944 NMTC patients, 81 (2.75%) patients had familial NMTC. We compared 66 patients with familial NMTC and 66 sporadic NMTC patients. There was no significant difference in first thyroglobulin, initial and accumulative iodine dose, and additional treatments (additional surgery and radiotherapy) between patients and controls. Although no significant difference was noted in one and two years' responses to treatment between the case and control groups, familial NMTC patients required more time to achieve excellent response (26.7 ± 24.9 versus 15.9 ± 9.0 months, P = 0.01). No significant difference was noted between familial NMTC patients with two or more than two involved relatives.

CONCLUSIONS

Our study showed that if patients with familial NMTCs were treated in the same way as non-familial patients, the time to excellent response would be significantly longer, even when they have only one other involved relative.

Non-medullary Thyroid Cancer Susceptibility Genes: Evidence and Disease Spectrum

BACKGROUND

The prevalence of non-medullary thyroid cancer (NMTC) is increasing worldwide. Although most NMTCs grow slowly, conventional therapies are less effective in advanced tumors. Approximately 5-15% of NMTCs have a significant germline genetic component. Awareness of the NMTC susceptibility genes may lead to earlier diagnosis and better cancer prevention.

OBJECTIVE

The aim of this study was to provide the current panorama of susceptibility genes associated with NMTC and the spectrum of diseases associated with these genes.

METHODS

Twenty-five candidate genes were identified by searching for relevant studies in PubMed. Each candidate gene was carefully checked using six authoritative genetic resources: ClinGen, National Comprehensive Cancer Network guidelines, Online Mendelian Inheritance in Man, Genetics Home Reference, GeneCards, and Gene-NCBI, and a validated natural language processing (NLP)-based literature review protocol was used to further assess gene-disease associations where there was ambiguity.

RESULTS

Among 25 candidate genes, 10 (APC, DICER1, FOXE1, HABP2, NKX2-1, PRKAR1A, PTEN, SDHB, SDHD, and SRGAP1) were verified among the six genetic resources. Two additional genes, CHEK2 and SEC23B, were verified using the NLP protocol. Seventy-nine diseases were found to be associated with these 12 NMTC susceptibility genes. The following diseases were associated with more than one NMTC susceptibility gene: colorectal cancer, breast cancer, gastric cancer, kidney cancer, gastrointestinal stromal tumor, paraganglioma, pheochromocytoma, and benign skin conditions.

CONCLUSION

Twelve genes predisposing to NMTC and their associated disease spectra were identified and verified. Clinicians should be aware that patients with certain pathogenic variants may require more aggressive surveillance beyond their thyroid cancer risk.

Genomics and Epigenomics of Medullary Thyroid Carcinoma: From Sporadic Disease to Familial Manifestations

Our understanding of the genomics and epigenomics of medullary thyroid carcinoma (MTC) has advanced since the initial recognition of RET as a driver of MTC tumorigenesis in familial MTC. We now have insight into the frequency and prognostic significance of specific RET mutations in sporadic MTC. For example, the most common RET mutation in sporadic MTC is the RET Met918Thr mutation, the same mutation that underlies MEN2B and a poor prognosticator. This mutation is relatively infrequent in medullary thyroid microcarcinomas but is over-represented in advanced-stage disease. RAS mutations are detected in 70% of sporadic, RET wild-type MTC. Although next-generation and whole-exome sequencing studies have shown that tumors that are wild-type for RET and RAS mutations essentially lack other recurrent mutations, additional pathways and epigenetic alterations have been implicated in MTC tumorigenesis. Increased insight into the clinical course of patients with familial MTC with specific RET mutations has guided treatment recommendations for these patients. Finally, an understanding of the genomics has informed treatment for patients with advanced MTC. In this review, we will examine the genomics and epigenomics of sporadic and familial MTC, along with the prognostic significance of molecular alterations, management of patients with germline RET mutations, and treatment strategies for MTC patients.

Inherited Follicular Epithelial-Derived Thyroid Carcinomas: From Molecular Biology to Histological Correlates

Cancer derived from thyroid follicular epithelial cells is common; it represents the most common endocrine malignancy. The molecular features of sporadic tumors have been clarified in the past decade. However the incidence of familial disease has not been emphasized and is often overlooked in routine practice. A careful clinical documentation of family history or familial syndromes that can be associated with thyroid disease can help identify germline susceptibility-driven thyroid neoplasia. In this review, we summarize a large body of information about both syndromic and non-syndromic familial thyroid carcinomas. A significant number of patients with inherited non-medullary thyroid carcinomas manifest disease that appears to be sporadic disease even in some syndromic cases. The cytomorphology of the tumor(s), molecular immunohistochemistry, the findings in the non-tumorous thyroid parenchyma and other associated lesions may provide insight into the underlying syndromic disorder. However, the increasing evidence of familial predisposition to non-syndromic thyroid cancers is raising questions about the importance of genetics and epigenetics. What appears to be "sporadic" is becoming less often truly so and more often an opportunity to identify and understand novel genetic variants that underlie tumorigenesis. Pathologists must be aware of the unusual morphologic features that should prompt germline screening. Therefore, recognition of harbingers of specific germline susceptibility syndromes can assist in providing information to facilitate early detection to prevent aggressive disease.

Inherited Thyroid Tumors With Oncocytic Change

Familial non-medullary thyroid carcinoma (FNMTC) corresponds to 5-10% of all follicular cell-derived carcinoma (FCDTC). Oncocytic thyroid tumors have an increased incidence in the familial context in comparison with sporadic FCDTC, encompassing benign and malignant tumors in the same family presenting with some extent of cell oxyphilia. This has triggered the interest of our and other groups to clarify the oncocytic change, looking for genetic markers that could explain the emergence of this phenotype in thyroid benign and malignant lesions, focusing on familial aggregation. Despite some advances regarding the identification of the gene associated with retinoic and interferon-induced mortality 19 (GRIM-19), as one of the key candidate genes affected in the "Tumor with Cell Oxyphilia" (TCO) locus, most of the mutations follow a pattern of "private mutations", almost exclusive to one family. Moreover, no causative genetic alterations were identified so far in most families. The incomplete penetrance of the disease, the diverse benign and malignant phenotypes in the affected familial members and the variable syndromic associations create an additional layer of complexity for studying the genetic alterations in oncocytic tumors. In the present review, we summarized the available evidence supporting genomic-based mechanisms for the oncocytic change, particularly in the context of FNMTC. We have also addressed the challenges and gaps in the aforementioned mechanisms, as well as molecular clues that can explain, at least partially, the phenotype of oncocytic tumors and the respective clinico-pathological behavior. Finally, we pointed to areas of further investigation in the field of oncocytic (F)NMTC with translational potential in terms of therapy.

Genetic Mutations and Variants in the Susceptibility of Familial Non-Medullary Thyroid Cancer

Thyroid cancer is the most frequent endocrine malignancy with the majority of cases derived from thyroid follicular cells and caused by sporadic mutations. However, when at least two or more first degree relatives present thyroid cancer, it is classified as familial non-medullary thyroid cancer (FNMTC) that may comprise 3-9% of all thyroid cancer. In this context, 5% of FNMTC are related to hereditary syndromes such as Cowden and Werner Syndromes, displaying specific genetic predisposition factors. On the other hand, the other 95% of cases are classified as non-syndromic FNMTC. Over the last 20 years, several candidate genes emerged in different studies of families worldwide. Nevertheless, the identification of a prevalent polymorphism or germinative mutation has not progressed in FNMTC. In this work, an overview of genetic alteration related to syndromic and non-syndromic FNMTC is presented.

Construction and analysis of an aberrant lncRNA-miRNA-mRNA network associated with papillary thyroid cancer

Accumulating evidence has indicated that long noncoding RNAs (lncRNAs) are the main constituents of competing endogenous RNA (ceRNA) networks. Nonetheless, in the lncRNA-related ceRNA network of papillary thyroid cancer (PTC), the function of cancer-specific lncRNAs, as well as their use for the potential prediction of PTC prognosis, remains unclear. In this study, 384 RNA sequencing (RNA-seq) profiles of PTC patients were attained from The Cancer Genome Atlas (TCGA), an open-source database that offers vast amounts of RNA-seq data, and 75 miRNAs, 495 lncRNAs, and 1099 mRNAs (P < .05 and |logFC| >2) were detected when compared with normal tissues. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were analyzed using the Cytoscape plug-in BinGo. An aberrant lncRNA-mRNA-miRNA ceRNA network consisting of 31 differentially expressed (DE)-lncRNAs, 13 DE-miRNAs, and 134 DE-mRNAs was built in TCGA. On the basis of overall survival (OS) analysis, 6 lncRNAs (CCAT1, SYNPR, SFTA1P, HOTAIR, HCG22, and CLDN10) were identified as prognostic biomarkers for patients in TCGA (P < .05). Through qRT-PCR, we designated 6 cancer-specific lncRNAs as having great significance for survival by verifying their expression in the 60 PTC patients who were diagnosed. The qRT-PCR and TCGA results were completely consistent. Our research provides data for further understanding the lncRNA-miRNA-mRNA ceRNA network and elucidating the molecular mechanisms of PTC.

Familial non-medullary thyroid carcinoma: clinico-pathological features, current knowledge and novelty regarding genetic risk factors

Familial non-medullary thyroid cancer (FNMTC) constitutes 3-9% of all thyroid cancers and occurs in two or more first-degree relatives in the absence of predisposing environmental factors. Out of all FNMTC cases, only 5% are represented by syndromic forms (Gardner's Syndrome, familial adenomatous polyposis, Cowden's Syndrome, Carney complex 1, Werner's Syndrome and DICER1 syndrome), in which thyroid cancer occurs as a minor component and the genetic alterations are well-known. The non-syndromic forms represent the majority of all FNMTCs (95%), and the thyroid cancer is the predominant feature. Several low penetration susceptibility risk loci or genes (i.e. TTF1, FOXE1, SRGAP1, SRRM2, HABP2, MAP2K5, and DUOX2), here fully reviewed, have been proposed in recent years with a possible causative role, though the results are still not conclusive or reliable. FNMTC is indistinguishable from sporadic non-medullary thyroid cancer (sNMTC), which means that FNMTC cannot be diagnosed until at least one of the patient's first-degree relatives is affected by tumor. Some studies reported that the non-syndromic FNMTC is more aggressive than the sNMTC, being characterized by a younger age of onset and a higher rate of multifocal and bilateral tumors, extrathyroidal extension, lymph node metastasis, and recurrence. On the contrary, other studies did not find clinical differences between non-syndromic FNMTCs and sporadic cases. Here, I reported an extensive review on genetic and clinico-pathological features of the FNMTC, with particular attention on novel genetic risk factors for non-syndromic forms.

[The role of molecular testing in thyroid tumors]

&sup1;I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia; &sup2;Endocrinology Research Centre, Moscow, Russia Thyroid cancer is the most common endocrine gland cancer. In the last few decades, the molecular diagnostics for thyroid tumors have been widely researched. It is one of the few cancers whose incidence has increased in recent years from microcarcinomas to common, large forms, in all age groups, from children to the elder people. Most researches focus on the genetic basis, since our current knowledge of the genetic background of various forms of thyroid cancer is far from being complete. Molecular and genetic research has several main directions: firstly, differential diagnosis of thyroid tumors, secondly, the prognostic value of detected mutations in thyroid cancer, and thirdly, targeted therapy for aggressive or radioactive iodine-resistant forms of thyroid cancer. In this review, we wanted to update our understanding and describe the prevailing advances in molecular genetics of thyroid cancer, focusing on the main genes associated with the pathology and their potential application in clinical practice.

A Support Vector Machine Model Predicting the Risk of Duodenal Cancer in Patients with Familial Adenomatous Polyposis at the Transcript Levels

Objective

Familial adenomatous polyposis (FAP) is one major type of inherited duodenal cancer. The estimate of duodenal cancer risk in patients with FAP is critical for selecting the optimal treatment strategy.

Methods

Microarray datasets related with FAP were retrieved from the Gene Expression Omnibus (GEO) database. Differentially expressed genes were identified by FAP vs. normal samples and FAP and duodenal cancer vs. normal samples. Furthermore, functional enrichment analyses of these differentially expressed genes were performed. A support vector machine (SVM) was performed to train and validate cancer risk prediction model.

Results

A total of 196 differentially expressed genes were identified between FAP compared with normal samples. 177 similarly expressed genes were identified both in FAP and duodenal cancer, which were mainly enriched in pathways in cancer and metabolic-related pathway, indicating that these genes in patients with FAP could contribute to duodenal cancer. Among them, Cyclin D1, SDF-1, AXIN, and TCF were significantly upregulated in FAP tissues using qRT-PCR. Based on the 177 genes, an SVM model was constructed for prediction of the risk of cancer in patients with FAP. After validation, the model can accurately distinguish FAP patients with high risk from those with low risk for duodenal cancer.

Conclusion

This study proposed a cancer risk prediction model based on an SVM at the transcript levels.

Long-Term Clinical Outcome in Familial and Sporadic Papillary Thyroid Carcinoma

BACKGROUND

The definition and the behaviour of familial papillary thyroid cancer (FPTC) compared to the sporadic form (SPTC) are still debated. Some authors believe that only families with 3 or more affected members represent an actual example of familial diseases.

OBJECTIVES

The objective of the study was to analyse the clinicopathological features and the outcome of sporadic and familial PTC patients also according to the number of affected members.

METHODS

Among 731 patients, we identified 101 (13.8%) with familial diseases, 79 with 2 affected members (FPTC-2) and 22 with 3 or more affected members (FPTC-3) followed for a mean period of 10 years.

RESULTS

FPTC patients had more frequently bilateral tumour (p = 0.007). No difference was found between the 2 groups for the other evaluated variables. At the time of the first follow-up (1-2 years after initial therapy), FPTC patients had a higher rate of persistent disease. However, at the last follow-up, the clinical outcome was not different between sporadic and familial patients. When the comparison between SPTC and FPTC was performed, according to the number of affected members, a significant trend between the 3 groups was observed for tumour diameter (p = 0.002) and bilaterality (p = 0.003), while we did not observe a significant trend for both response to initial therapy (p = 0.15) and last clinical outcome (p = 0.22).

CONCLUSIONS

Our results suggest that, although the clinicopathological features of FPTC may be more aggressive, the long-term outcome is similar between FPTC and SPTC. A possible explanation is that PTC has a favourable prognosis, even when clinical presentation is more aggressive.

Intermixed medullary and papillary thyroid cancer in a patient with renal cell carcinoma

SUMMARY

We report a rare case of concurrent medullary thyroid cancer (MTC) and papillary thyroid cancer (PTC) with intermixed disease in several of the lymph node (LN) metastases in a patient who was subsequently diagnosed with clear cell renal cell carcinoma (RCC). A 56 year old female presented with dysphagia and was found to have a left thyroid nodule and left superior cervical LN with suspicious sonographic features. Fine needle aspiration biopsy (FNAB) demonstrated PTC in the left thyroid nodule and MTC in the left cervical LN. Histopathology demonstrated multifocal PTC with 3/21 LNs positive for metastatic PTC. One LN in the left lateral neck dissection exhibited features of both MTC and PTC within the same node. In the right lobe, a 0.3 cm focus of MTC with extra-thyroidal extension was noted. Given persistent calcitonin elevation, a follow-up ultrasound displayed an abnormal left level 4 LN. FNAB showed features of both PTC and MTC on the cytopathology itself. The patient underwent repeat central and left radical neck dissection with 3/6 LNs positive for PTC in the central neck and 2/6 LNs positive for intermixed PTC and MTC in the left neck. There was no evidence of distant metastases on computed tomography and whole body scintigraphy, however a 1.9 x 2.5 cm enhancing mass within the right inter-polar kidney was discovered. This lesion was highly suspicious for RCC. Surgical pathology revealed a 2.5 cm clear cell RCC, Fuhrman grade 2/4, with negative surgical margins. She continues to be observed with stable imaging of her triple malignancies.

LEARNING POINTS

Mixed medullary-papillary thyroid neoplasm is characterized by the presence of morphological and immunohistochemical features of both medullary and papillary thyroid cancers within the same lesion. Simultaneous occurrence of these carcinomas has been previously reported, but a mixed disease within the same lymph node is an infrequent phenomenon. Prognosis of mixed medullary-papillary thyroid carcinomas is determined by the medullary component. Therefore, when PTC and MTC occur concurrently, the priority should be given to the management of MTC, which involves total thyroidectomy and central lymph node dissection. Patients with thyroid cancer, predominantly PTC, have shown higher than expected rates of RCC. To our knowledge, this is the first report describing the combination of MTC, PTC, and RCC in a single patient.

[Hereditary predispositions to follicular thyroid tumors]

Familial thyroid cancers of follicular origin are rare and include syndromic and non-syndromic tumours. In familial adenomatous polyposis, the prevalence of papillary thyroid cancer is 2-12% and in 20-40% of cases it is a cribriform-morular papillary thyroid carcinoma. Morules and cribriform pattern are the two main typical criteria, associated with a nuclear and cytoplasmic immunopositivity for beta catenin. DICER1 syndrome is associated with pleuropneumoblastoma, ovarian tumors and thyroid pathology (multinodular goiter and less frequently a well-differentiated thyroid cancer without microscopic particularity). Cowden syndrome is characterized by multiple hamartomas and two-thirds of patients develop thyroid pathology, including multinodular goiter (50-67%) and cancer (35%), the latter being one of the major diagnostic criteria of the syndrome. Classic triad of Carney complex associates lentiginosis, myxoid tumors, and various endocrine abnormalities; thyroid pathology occurs in 10% of cases and may be benign or malignant. In Werner's syndrome, thyroid cancer is present in 18% of cases. McCune-Albright syndrome is characterized by fibrous dysplasia, café-au-lait spots and various endocrinopathies including hyperthyroidism and nodular hyperplasia. Non-syndromic thyroid cancers, which represent the majority of familial cancers, are most often papillary carcinomas. In daily practice, in the presence of multiple benign thyroid nodules and/or thyroid cancer in a young person, or with family thyroid diseases, the pathologist should be aware about hereditary predispositions to propose an oncogenetic consultation.

Clinical and Genetic Features of a Large Monocentric Series of Familial Non-Medullary Thyroid Cancers

Several low penetration susceptibility risk loci or genes have been proposed in recent years with a possible causative role for familial non-medullary thyroid cancer (FNMTC), though the results are still not conclusive or reliable. Among all the candidates, here fully reviewed, a new extremely rare germline variant c.3607A>G (p.Y1203H) of the DUOX2 gene, has been recently reported to co-segregate with the affected members of one non-syndromic FNMTC family. We aimed to validate this finding in our series of 33 unrelated FNMTC Italian families, previously found to be negative for two susceptibility germline variants in the HABP2 and MAP2K5 genes. Unfortunately, the DUOX2 p.Y1203H variant was not found in either the 74 affected or the 12 not affected family members of our series. We obtained interesting data by comparing the clinico-pathological data of the affected members of our kindreds with a large consecutive series of sporadic cases, followed at our site. We found that familial tumors had a statistically significant more aggressive presentation at diagnosis, though not resulting in a worst outcome. In conclusion, we report genetic and clinical data in a large series of FNMTC kindreds. Our families are negative for variants reported as likely causative, namely those lying in the HABP2, MAP2K5 and DUOX2 genes. The extensive review of the current knowledge on the genetic risk factors for non-syndromic FNMTCs underlies how the management of these tumors remains mainly clinical. Despite the more aggressive presentation of familial cases, an appropriate treatment leads to an outcome similar to that observed for sporadic cases.

A Guide to Pheochromocytomas and Paragangliomas

Pheochromocytomas and extra-adrenal paragangliomas are rare neuroendocrine neoplasms with characteristic histologic and immunohistochemical features. These tumors can arise in several anatomic locations, necessitating that their diagnostic recognition extends beyond the realm of endocrine disorders. A practical and reproducible risk stratification system for these tumors is still in development. In this rapidly evolving era of molecular medicine, it is essential for pathologists to equip themselves with a framework for understanding the classification of paragangliomas and pheochromocytomas and be informed of how they might advise their colleagues with regard to prognostication and appropriate follow-up.

Influencers on Thyroid Cancer Onset: Molecular Genetic Basis

Thyroid cancer, a cancerous tumor or growth located within the thyroid gland, is the most common endocrine cancer. It is one of the few cancers whereby incidence rates have increased in recent years. It occurs in all age groups, from children through to seniors. Most studies are focused on dissecting its genetic basis, since our current knowledge of the genetic background of the different forms of thyroid cancer is far from complete, which poses a challenge for diagnosis and prognosis of the disease. In this review, we describe prevailing advances and update our understanding of the molecular genetics of thyroid cancer, focusing on the main genes related with the pathology, including the different noncoding RNAs associated with the disease.

Alazami syndrome: the first case of papillary thyroid carcinoma

Alazami syndrome (MIM#615071) is a rare developmental disorder caused by biallelic variants in the LARP7 gene. Hallmark features include short stature, global developmental delay, and distinctive facial features. To date, 23 patients from 11 families have been reported in the literature. Here we describe a 19-year-old man who, in association with the typical features of Alazami syndrome, was diagnosed at the age of 14 years with papillary thyroid carcinoma, harboring the somatic BRAF V600E mutation. Whole exome sequencing revealed two novel LARP7 variants in compound heterozygosity, whereas only common variants were detected in genes associated with familial nonmedullary thyroid cancer (MIM#188550). LARP7 acts as a tumor suppressor in breast and gastric cancer, and possibly, according to recent studies, in thyroid tumors. Since thyroid cancer is rare among children and adolescents, we hypothesize that the LARP7 variants identified in our patient are responsible for both Alazami syndrome and tumor susceptibility. We also provide an overview of the clinical findings in all Alazami syndrome patients reported to date and discuss the possible pathogenetic mechanism that may underlie this condition, including the role of LARP7 in tumor susceptibility.

Current Knowledge of Germline Genetic Risk Factors for the Development of Non-Medullary Thyroid Cancer

The thyroid is the most common site of endocrine cancer. One type of thyroid cancer, non-medullary thyroid cancer (NMTC), develops from follicular cells and represents approximately 90% of all thyroid cancers. Approximately 5%–15% of NMTC cases are thought to be of familial origin (FNMTC), which is defined as the occurrence of the disease in three or more first-degree relatives of the patient. It is often divided into two groups: Syndrome-associated and non-syndromic. The associated syndromes include Cowden syndrome, familial adenomatous polyposis, Gardner syndrome, Carney complex and Werner syndrome. The hereditary factors contributing to the unfavorable course of FNMTC remain poorly understood; therefore, considerable effort is being expended to identify contributing loci. Research carried out to date identifies fourteen genes (DICER1, FOXE1, PTCSC2, MYH9, SRGAP1, HABP2, BRCA1, CHEK2, ATM, RASAL1, SRRM2, XRCC1, TITF-1/NKX2.1, PTCSC3) associated with vulnerability to FNMTC that are not related to hereditary syndromes. In this review, we summarize FNMTC studies to date, and provide information on genes involved in the development of non-syndromic familial non-medullary thyroid cancers, and the significance of mutations in these genes as risk factors. Moreover, we discuss whether the genetic polymorphism rs966423 in DIRC3 has any potential as a prognostic factor of papillary thyroid cancer.

Integrating clinical, molecular, proteomic and histopathological data within the tissue context: tissunomics

Malignant tumours show a marked degree of morphological, molecular and proteomic heterogeneity. This variability is closely related to microenvironmental factors and the location of the tumour. The activation of genetic alterations is very tissue‐dependent and only few tumours have distinct genetic alterations. Importantly, the activation state of proteins and signaling factors is heterogeneous in the primary tumour and in metastases and recurrences. The molecular diagnosis based only on genetic alterations can lead to treatments with unpredictable responses, depending on the tumour location, such as the tumour response in melanomas versus colon carcinomas with BRAF mutations. Therefore, we understand that the correct evaluation of tumours requires a system that integrates both morphological, molecular and protein information in a clinical and pathological context, where intratumoral heterogeneity can be assessed. Thus, we propose the term ‘tissunomics’, where the diagnosis will be contextualised in each tumour based on the complementation of the pathological, molecular, protein expression, environmental cells and clinical data.

New and Emerging Biomarkers in Endocrine Pathology

Significant advances in genomics and molecular genetics in recent years have reshaped the practice of endocrine pathology. Pan-genomic studies, including the pioneering ones on papillary thyroid carcinoma, phaeochromocytoma/paraganglioma, and adrenal cortical carcinoma from the Cancer Genome Atlas (TCGA) project, provided a comprehensive integrated genomic analysis of endocrine tumors into distinct molecularly defined subtypes. Better understanding of the molecular landscape and more accurate definition of biological behavior has been accordingly achieved. Nevertheless, how any of these advances are translated into routine practice still remains a challenge in the era of precision medicine. The challenge for modern pathology is to keep up the pace with scientific discoveries by integrating novel concepts in tumor classification, molecular genetics, prognostication, and theranostics. As an example, pathology plays a role in the identification of hereditary disease, while it offers the tools for complementing molecular genetics, for example, validation of variants of unknown significance deriving from targeted sequencing or whole exome/genome sequencing approach. Immunohistochemistry has arisen as a cost-effective strategy in the evaluation either of somatic mutations in tumors and/or germline mutations in patients with familial cancer syndromes. Herein, a comprehensive review focusing on novel and emerging biomarkers is presented in order pathologists and other endocrine-related specialists to remain updated and become aware of potential pitfalls and limitations in the field of endocrine pathology.

Medullary Thyroid Carcinoma and Papillary Thyroid Carcinoma in the Same Patient as a Collision Tumour

Aim

Papillary thyroid carcinoma (PTC) and medullary thyroid carcinoma (MTC) are two different types of thyroid carcinoma with significant different clinical and histological findings. Their coexistence in the same patient is a very rare event which demands different clinical approach.

Case Report

We report a case with concurrent MTC and PTC in the same thyroid having characteristics of a collision tumour. A 35-year-old patient has admitted to endocrinology outpatient department with complaint of pain in the neck. Physical examination revealed 2 cm nodule on the thyroid right lobe. Serum thyroid hormone levels were within normal range. Ultrasonography revealed a 23x15 mm hypoechoic nodule with micro calcifications and cystic areas on the right lobe. Preoperative serum calcitonin was 2 pg/ml (0-11.5). PTK 1.7 cm and MTK 1.8 cm in the same thyroid with healthy tissue in between them were detected on pathological examination. RET gene mutation was negative. She has been followed up to now without any evidence of disease.

Conclusion

This is a collision tumour since lesions with features of MTC and PTC were detected in two different locations and separated by normal thyroid tissue. Germline point mutation of the RET gene had a potential role in the development of both MTC and PTC. On the other side, familial concurrent MTC and PTC without RET gene mutation was also published. Both RET and BRAF genes had a role in the development of the medullary and papillary collision tumours. We do not know the presence of BRAF gene mutation in this case report yet.

Surgical management of follicular thyroid carcinoma in children and adolescents: A study of 30 cases

BACKGROUND/PURPOSE

The purpose of the study is to describe the anatomoclinical, diagnostic, therapeutic and prognostic aspects of pediatric follicular thyroid carcinoma (FTC) in order to choose the best therapeutic strategy.

METHODS

Our study includes patients ≤18 years old surgically treated for FTC in four Italian Pediatric Surgery Centers from January 2000 to March 2017. The collected data were compared with those of 132 patients matched for age with a histological diagnosis of papillary thyroid carcinoma (PTC) surgically treated in the same institutions during the same period and with the data of patients diagnosed with FTC found in the literature; p-values <0.05 were considered significant.

RESULTS

21 (70%) of the 30 patients with a histological diagnosis of FTC underwent hemithyroidectomy while 9 (30%) underwent total thyroidectomy. 11 (55%) out of 21 patients were subjected to a completion of thyroidectomy. All patients are alive (OS = 100%) without recurrence or relapse of the disease. Compared with PTC, FTC is significant for capsule infiltration (p < 0.0001), vascular invasion (p = 0.0014) and T-stage T3-T4 (p = 0.013). However, multifocality (p < 0.001), extrathyroid extension (p < 0.0001) and lymph node metastasis (p < 0.0001) are more evident in PTC.

CONCLUSION

The conservative approach seems to be a valid surgical treatment for pediatric patients diagnosed with MI-FTC. For patients with wide vascular invasion and/or a tumor >4 cm, especially with high after-surgery Tg rate, a completion of thyroidectomy is recommended. In patients with multifocal neoplasia, and/or tumor size ≥4 cm, and/or extrathyroid extension, and/or lymph node metastasis, and/or distant metastasis, total thyroidectomy followed by radioiodine therapy is generally indicated.

LEVELS OF EVIDENCE

II.

Knockdown of lncRNA UCA1 inhibits proliferation and invasion of papillary thyroid carcinoma through regulating miR-204/IGFBP5 axis

Background

Long noncoding RNA (LncRNA) UCA1 has been reported to function as an oncogene in multiple cancers. However, the biological roles and underlying mechanism of UCA1 in papillary thyroid carcinoma (PTC) remain unclear. This study aimed to investigate the underlying function of UCA1 on thyroid cancer progression.

Materials and methods

A series of experiments involving Cell Counting Kit-8, wound-healing, and transwell invasion assays were conducted to determine the cellular capabilities of proliferation, migration, and invasion, respectively. Binding sites between UCA1 and miR-204 were identified using a luciferase reporter system, whereas mRNA and protein expression of target genes were determined by real-time quantitative reverse transcription-PCR (qRT-PCR) and Western blot, respectively.

Results

The results revealed that UCA1 was upregulated in PTC tissue and cell lines. UCA1 knockdown significantly suppressed the cell proliferation, migration, and invasion of TPC-1 cells. Bioinformatics analysis and luciferase reporter assay verified the complementary binding within UCA1 and miR-204 at the 3′-UTR. Moreover, miR-204 inhibition reversed the UCA1 knockdown-mediated inhibitory effect on cell proliferation, migration, and invasion. We also found that UCA1 could regulate expression of IGFBP5, a direct target of miR-204 in PTC.

Conclusion

Our study demonstrated that UCA1 exerts activity of oncogenes in PTC through regulating miR-204/IGFBP5 axis.