The Cancer Genomics Resource List 2014

Context.— Genomic sequencing for cancer is offered by commercial for-profit laboratories, independent laboratory networks, and laboratories in academic medical centers and integrated health networks. The variability among the tests has created a complex, confusing environment. Objective.— To address the complexity, the Personalized Health Care (PHC) Committee of the College of American Pathologists proposed the development of a cancer genomics resource list (CGRL). The goal of this resource was to assist the laboratory pathology and clinical oncology communities. Design.— The PHC Committee established a working group in 2012 to address this goal. The group consisted of site-specific experts in cancer genetic sequencing. The group identified current next-generation sequencing (NGS)–based cancer tests and compiled them into a usable resource. The genes were annotated by the working group. The annotation process drew on published knowledge, including public databases and the medical literature. Results.— The compiled list includes NGS panels offered by 19 laboratories or vendors, accompanied by annotations. The list has 611 different genes for which NGS-based mutation testing is offered. Surprisingly, of these 611 genes, 0 genes were listed in every panel, 43 genes were listed in 4 panels, and 54 genes were listed in 3 panels. In addition, tests for 393 genes were offered by only 1 or 2 institutions. Table 1 provides an example of gene mutations offered for breast cancer genomic testing with the annotation as it appears in the CGRL 2014. Conclusions.— The final product, referred to as the Cancer Genomics Resource List 2014, is available as supplemental digital content

Nomenclature revision for encapsulated follicular variant of papillary thyroid carcinoma:a paradigm shift to reduce overtreatment of indolent tumors

Although growing evidence points to highly indolent behavior of encapsulated follicular variant of papillary thyroid carcinoma (EFVPTC), most patients with EFVPTC are treated as having conventional thyroid cancer

Prevalence of RET/PTC rearrangements in thyroid papillary carcinomas: Effects of the detection methods and genetic heterogeneity

CONTEXT: RET/PTC rearrangements have been reported in papillary thyroid carcinomas with variable frequency in studies that used different detection methods. OBJECTIVE: Our objective was to determine the role of different detection methods and tumor genetic heterogeneity on RET/PTC detection. DESIGN: Sixty-five papillary carcinomas were analyzed for RET/PTC1 and RET/PTC3 using five detection methods: standard-sensitivity RT-PCR, high-sensitivity RT-PCR, real-time LightCycler RT-PCR, Southern blot analysis, and fluorescence in situ hybridization. RESULTS: RET/PTC rearrangements were detected by standard-sensitivity RT-PCR in 14 tumors. High-sensitivity RT-PCR detected RET/PTC in all of these and in 12 additional cases, where the levels of expression corresponded to one to five positive cells. Real-time LightCycler RT-PCR detected RET/PTC in 12 and Southern blot analysis in 11 tumors. By fluorescence in situ hybridization, 14 tumors were positive, including nine cases with 50-86% positive cells and five cases with 17-35% positive cells. Overall, nine (14%) tumors harbored clonal rearrangements, which were present in the majority of tumor cells and detected by all five methods. Five (8%) cases had subclonal rearrangements present in a smaller portion of tumor cells and detected by most methods. Twelve (18%) tumors had nonclonal RET/PTC that were detected only by high-sensitivity RT-PCR. No other mutations were found in tumors harboring clonal RET/PTC, whereas 60% of tumors with subclonal and 42% of tumors with nonclonal RET/PTC harbored additional mutations. CONCLUSIONS: Our data suggest that broad variability in the reported prevalence of RET/PTC rearrangement is at least in part a result of the use of different detection methods and tumor genetic heterogeneity

MicroRNA profile of poorly differentiated thyroid carcinomas: new diagnostic and prognostic insights.

The diagnosis of conventional and oncocytic poorly differentiated (oPD) thyroid carcinomas is difficult. The aim of this study is to characterise their largely unknown miRNA expression profile and to compare it with well-differentiated thyroid tumours, as well as to identify miRNAs which could potentially serve as diagnostic and prognostic markers. A total of 14 poorly differentiated (PD), 13 oPD, 72 well-differentiated thyroid carcinomas and eight normal thyroid specimens were studied for the expression of 768 miRNAs using PCR-Microarrays. MiRNA expression was different between PD and oPD thyroid carcinomas, demonstrating individual clusters on the clustering analysis. Both tumour types showed upregulation of miR-125a-5p, -15a-3p, -182, -183-3p, -222, -222-5p, and downregulation of miR-130b, -139-5p, -150, -193a-5p, -219-5p, -23b, -451, -455-3p and of miR-886-3p as compared with normal thyroid tissue. In addition, the oPD thyroid carcinomas demonstrated upregulation of miR-221 and miR-885-5p. The difference in expression was also observed between miRNA expression in PD and well-differentiated tumours. The CHAID algorithm allowed the separation of PD from well-differentiated thyroid carcinomas with 73-79% accuracy using miR-23b and miR-150 as a separator. Kaplan-Meier and multivariate analysis showed a significant association with tumour relapses (for miR-23b) and with tumour-specific death (for miR-150) in PD and oPD thyroid carcinomas. MiRNA expression is different in conventional and oPD thyroid carcinomas in comparison with well-differentiated thyroid cancers and can be used for discrimination between these tumour types. The newly identified deregulated miRNAs (miR-150, miR-23b) bear the potential to be used in a clinical setting, delivering prognostic and diagnostic informations

Comprehensive microRNA expression profiling identifies novel markers in follicular variant of papillary thyroid carcinoma

Background: Follicular variant of papillary thyroid carcinoma (FVPTC) shares features of papillary (PTC) and follicular (FTC) thyroid carcinomas on a clinical, morphological, and genetic level. MiRNA deregulation was extensively studied in PTCs and FTCs; however, very limited information is available for FVPTC. The aim of this study was to assess miRNA expression in FVPTC with the most comprehensive miRNA array panel and correlate it with the clinicopathological data. Methods: Forty-four papillary thyroid carcinomas (17 FVPTC, 27 classic PTC) and 8 normal thyroid tissue samples were analyzed for expression of 748 miRNAs using Human Microarray Assays on ABI 7900 (Life Technologies). In addition, an independent set of 61 tumor and normal samples was studied for expression of novel miRNA markers detected in this study. Results: Overall, the miRNA expression profile demonstrated similar trends in expression between FVPTC and classic PTC. Fourteen miRNAs were deregulated in FVPTC with a fold change of more than 5 (up/down) including miRNAs known to be upregulated in PTC (miR-146b-3p, -146-5p, -221, -222 and miR-222-5p) and novel miRNAs (miR-375, -551b, 181-2-3p, 99b-3p). However, the levels of miRNA expression were different between these tumor types and some miRNAs were uniquely dysregulated in FVPTC allowing separation of these tumors on the unsupervised hierarchical clustering analysis. Upregulation of novel miR-375 was confirmed in a large independent set of follicular cell derived neoplasms and benign nodules and demonstrated specific upregulation for PTC. Two miRNAs (miR-181a-2-3p, miR-99b-3p) were associated with an adverse outcome in FVPTC patients by a Kaplan Meier (p<0.05) and multivariate Cox regression analysis (p<0.05). Conclusions: Despite high similarity in miRNA expression between FVPTC and classic PTC, several miRNAs were uniquely expressed in each tumor type supporting their histopathologic differences. Highly upregulated miRNA identified in this study (miR-375) can serve as a novel marker of papillary thyroid carcinoma and miR-181a-2-3p and miR-99b-3p can predict relapse free survival in patients with FVPTC potentially providing important diagnostic and predictive value

Detection of IDH1 and IDH2 Mutations by Fluorescence Melting Curve Analysis as a Diagnostic Tool for Brain Biopsies

Novel mutations in the isocitrate dehydrogenase 1 (IDH1) and 2 (IDH2) genes have been identified in a large proportion of diffuse gliomas. Tumors with IDH1/2 mutations have distinctive clinical characteristics, including a less aggressive course. The aim of this study was to develop and evaluate the performance of a novel real-time PCR and post-PCR fluorescence melting curve analysis assay for the detection of IDH1 and IDH2 mutations in routine formalin-fixed, paraffin-embedded tissues of brain biopsies. Using the established assay, we tested 67 glial neoplasms, 57 non-neoplastic conditions that can often mimic gliomas (eg, radiation changes, viral infections, infarctions, etc), and 44 noncentral nervous system tumors. IDH1 and IDH2 mutations were detected in 72% of lower grade diffuse gliomas and in 17% of glioblastomas. The IDH1 mutation was the most common (93%), with the most frequent subtype being R132H (88%). These mutations were not identified in non-neoplastic glioma mimickers and in noncentral nervous system tumors including thyroid carcinomas. The results of this assay had a 100% correlation with the results obtained by conventional sequencing. In summary, we report here the real-time PCR/fluorescence melting curve analysis assay that provides rapid and sensitive detection of IDH mutations in formalin-fixed, paraffin-embedded tissues, and is therefore useful as a powerful adjunct diagnostic tool for refining histopathological diagnosis of brain lesions and guiding patient management