Classification Of Thyroid Cancer Research Articles

Follicular cell thyroid neoplasia: insights from genomics and The Cancer Genome Atlas research network.

The present review is focused on the recently published study on the genomics of papillary thyroid carcinoma performed by The Cancer Genome Atlas Research Network and its implications for the follicular variant of papillary carcinoma. The Cancer Genome Atlas study of papillary thyroid carcinoma comprehensively examined the cancer genome of nearly 500 primary tumors. Using a highly integrated bioinformatic analysis, papillary carcinoma was shown at the genomic level to consist of two highly distinct classes that reflected both tumor histology and underlying genotype. Tumors with true papillary architecture were dominated by BRAF(V600E) mutations and RET kinase fusions and were designated as BRAF(V600E)-like. Tumors with follicular architecture were conversely dominated by RAS mutations and were designated as RAS-like. Given the strong genotype:phenotype correlation known to be present in thyroid cancer, the separation of BRAF(V600E)-like and RAS-like tumors has profound implications for its classification, especially the follicular variant of papillary carcinoma. The recent genomic characterization of papillary thyroid carcinoma is challenging the established pathological classification of thyroid cancer with significance for the care of patients.

Application of metabolomics in thyroid cancer research.

Thyroid cancer is the most common endocrine malignancy with four major types distinguished on the basis of histopathological features: papillary, follicular, medullary, and anaplastic. Classification of thyroid cancer is the primary step in the assessment of prognosis and selection of the treatment. However, in some cases, cytological and histological patterns are inconclusive; hence, classification based on histopathology could be supported by molecular biomarkers, including markers identified with the use of high-throughput “omics” techniques. Beside genomics, transcriptomics, and proteomics, metabolomic approach emerges as the most downstream attitude reflecting phenotypic changes and alterations in pathophysiological states of biological systems. Metabolomics using mass spectrometry and magnetic resonance spectroscopy techniques allows qualitative and quantitative profiling of small molecules present in biological systems. This approach can be applied to reveal metabolic differences between different types of thyroid cancer and to identify new potential candidates for molecular biomarkers. In this review, we consider current results concerning application of metabolomics in the field of thyroid cancer research. Recent studies show that metabolomics can provide significant information about the discrimination between different types of thyroid lesions. In the near future, one could expect a further progress in thyroid cancer metabolomics leading to development of molecular markers and improvement of the tumor types classification and diagnosis.

A Review on Ultrasound-Based Thyroid Cancer Tissue Characterization and Automated Classification

In this paper, we review the different studies that developed Computer Aided Diagnostic (CAD) for automated classification of thyroid cancer into benign and malignant types. Specifically, we discuss the different types of features that are used to study and analyze the differences between benign and malignant thyroid nodules. These features can be broadly categorized into (a) the sonographic features from the ultrasound images, and (b) the non-clinical features extracted from the ultrasound images using statistical and data mining techniques. We also present a brief description of the commonly used classifiers in ultrasound based CAD systems. We then review the studies that used features based on the ultrasound images for thyroid nodule classification and highlight the limitations of such studies. We also discuss and review the techniques used in studies that used the non-clinical features for thyroid nodule classification and report the classification accuracies obtained in these studies.

Molecular biology of thyroid cancer initiation

Thyroid cancers stand out among solid tumours because many of the tumour-initiating genetic events have been identified. Mutations leading to constitutive activation of MAP kinase effectors -the tyrosine receptor kinase RET and the intracellular signalling effectors RAS and BRAF- are essential for the pathogenesis of papillary thyroid carcinoma (PTC). Similarly, there is increasing evidence demonstrating that mutations leading to activation of the phosphatidylinositol 3- kinase (PI3K)/AKT effectors -PTEN and PI3KCa- are essential for the pathogenesis of follicular thyroid carcinoma (FTC). Besides this strong relationship between the histological phenotype and the pathway predominantly activated, the nature of the genetic event seems to determine the biological behaviour of the tumour and the ultimate clinical outcome of the patient. In this review we will summarise and discuss the main genetic events related to thyroid cancer initiation, the contribution of genomics and the convenience of using a new molecular classification of thyroid cancer, complementary to the clinicopathological classification. This may help us to predict more faithfully the clinical outcome of patients with thyroid cancer and to select more appropriately candidates for targeted therapies.

Incidence of thyroid cancer in New Caledonia, South Pacific, during 1985-1992.

This study was designed to estimate the incidence and describe characteristics of thyroid cancer among several ethnic groups in New Caledonia, South Pacific. The authors located all of the new pathology diagnoses of primary thyroid cancer that occurred in the 164,173 inhabitants (1989 census) from January 1985 to December 1992. Subject and disease characteristics were abstracted from medical records, and histology was classified according to the World Health Organization's histologic classification of thyroid cancer. The average annual rate of thyroid cancer was 9.1/100,000 population (119 subjects). The highest rates were observed in the Island of Lifu (31.5/100,000). The incidence was higher in females than in males (age-adjusted rate ratio = 7.83; 95% confidence interval (CI) 4.47-13.58) and in Melanesians than in other ethnic groups, especially in subjects aged 45-54 years (rate ratio = 8.27; 95% CI 3.36-20.35) and 55-64 years (rate ratio = 8.83; 95% CI 3.21-24.32). Most cancers were papillary (82 subjects); for follicular cancers, the increased risk among Melanesians was more marked after 44 years of age. Melanesians were also more likely to have a metastatic tumor than were other ethnic groups (rate ratio = 2.99; 95% CI 1.64-5.45). With the highest incidence rates ever reported, thyroid cancer is a major public health problem for Melanesians of New Caledonia.

Solitary thyroid nodule

The approach to management of an isolated thyroid nodule requires some understanding of the natural history of thyroid cancer and other forms of nodular thyroid disease. The histologic classification of thyroid cancer is an important determinant of survival, as are the size of the primary tumor, presence of thyroid capsule invasion, and presence of distant metastases. Therapeutic radiation and radioactive fallout increase the risk that a thyroid nodule is malignant. Autonomously functioning thyroid nodules are usually benign follicular adenomas and may cause thyrotoxicosis.

Observer variation in histologic classification of thyroid cancer.

Histologic slides of 696 cases of thyroid cancer reported to the national cancer registries of Finland, Iceland, Norway and Sweden were reviewed by 5 Nordic pathologists in order to determine the observer variation between the pathologists, as well as the reproducibility of the WHO classification of thyroid tumours. In 58% of the cases all observers agreed upon the diagnosis and in 82% at least three of them agreed. The observer disagreement was lowest for papillary carcinoma (7%) and highest for follicular carcinoma (27%). The corresponding figures for anaplastic and medullary carcinomas were 18% and 23%, respectively. The most common diverging diagnosis for cases finally interpreted as papillary carcinoma was follicular carcinoma, and for cases finally interpreted as follicular carcinoma, a benign thyroid lesion. The results of the present study clearly indicate the necessity of having all cases reviewed by the same pathologist or group of pathologists in order to obtain reliable results for comparative studies.

Thyroid cancer classification, clinical features, diagnosis and therapy

Summary The topic of thyroid cancer has been highly controversial in all its aspects, but most of all in its histologic classification and its management. The present section is an attempt to crystallize the vast literature in this area. The histology and the ultrastructure of thyroid tumors is discussed. The etiologic factors involved in the development of thyroid cancer are largely unknown; the high incidence of thyroid cancer in Hawaii points to important environmental factors causing malignancies in the thyroid. The importance of radiation to the neck area in childhood is another recognized etiologic factor in the development of thyroid tumors. Isotope scanning techniques are discussed. Ultrasonography is useful for the diagnosis of cystic lesions of the thyroid. Finally the variable surgical procedures used by various authors in the management of differentiated thyroid cancer is reviewed; the rationale for performing a total thyroidectomy in these cases, as advocated by the authors, is discussed. The use of radioiodine therapy following surgery', treatment with suppressive doses of thyroid hormone and the use of adriamycin as a treatment for thyroid cancer uncontrollable by other means are discussed.