Synchronous clear cell renal cell carcinoma and tubulocystic carcinoma: genetic evidence of independent ontogenesis and implications of chromosomal imbalances in tumor progression

Seven percent of renal cell carcinoma (RCC) cases are diagnosed as "unclassified" RCC by morphology. Genetic profiling of RCCs helps define renal tumor subtypes, especially in cases where morphologic diagnosis is inconclusive. This report describes a patient with synchronous clear cell RCC (ccRCC) and a tubulocystic renal carcinoma (TCRC) in the same kidney, and discusses the pathologic features and genetic profile of both tumors. A 67 year-old male underwent CT scans for an unrelated medical event. Two incidental renal lesions were found and ultimately removed by radical nephrectomy. The smaller lesion had multiple small cystic spaces lined by hobnail cells with high nuclear grade separated by fibrous stroma. This morphology and the expression of proximal (CD10, AMACR) and distal tubule cell (CK19) markers by immunohistochemistry supported the diagnosis of TCRC. The larger lesion was a typical ccRCC, with Fuhrman's nuclear grade 3 and confined to the kidney. Molecular characterization of both neoplasms using virtual karyotyping was performed to assess relatedness of these tumors. Low grade areas (Fuhrman grade 2) of the ccRCC showed loss of 3p and gains in chromosomes 5 and 7, whereas oncocytic areas displayed additional gain of 2p and loss of 10q; the high grade areas (Fuhrman grade 3) showed several additional imbalances. In contrast, the TCRC demonstrated a distinct profile with gains of chromosomes 8 and 17 and loss of 9. In conclusion, ccRCC and TCRC show distinct genomic copy number profiles and chromosomal imbalances in TCRC might be implicated in the pathogenesis of this tumor. Second, the presence of a ccRCC with varying degrees of differentiation exemplifies the sequence of chromosomal imbalances acquired during tumor progression

Virtual karyotyping with SNP microarrays reduces uncertainty in the diagnosis of renal epithelial tumors

<p>Abstract</p> <p>Background</p> <p>Renal epithelial tumors are morphologically, biologically, and clinically heterogeneous. Different morphologic subtypes require specific management due to markedly different prognosis and response to therapy. Each common subtype has characteristic chromosomal gains and losses, including some with prognostic value. However, copy number information has not been readily accessible for clinical purposes and thus has not been routinely used in the diagnostic evaluation of these tumors. This information can be useful for classification of tumors with complex or challenging morphology. 'Virtual karyotypes' generated using SNP arrays can readily detect characteristic chromosomal lesions in paraffin embedded renal tumors and can be used to correctly categorize the common subtypes with performance characteristics that are amenable for routine clinical use.</p> <p>Methods</p> <p>To investigate the use of virtual karyotypes for diagnostically challenging renal epithelial tumors, we evaluated 25 archived renal neoplasms where sub-classification could not be definitively rendered based on morphology and other ancillary studies. We generated virtual karyotypes with the Affymetrix 10 K 2.0 mapping array platform and identified the presence of genomic lesions across all 22 autosomes.</p> <p>Results</p> <p>In 91% of challenging cases the virtual karyotype unambiguously detected the presence or absence of chromosomal aberrations characteristic of one of the common subtypes of renal epithelial tumors, while immunohistochemistry and fluorescent in situ hybridization had no or limited utility in the diagnosis of these tumors.</p> <p>Conclusion</p> <p>These results show that virtual karyotypes generated by SNP arrays can be used as a practical ancillary study for the classification of renal epithelial tumors with complex or ambiguous morphology.</p

Relevance, Pathogenesis, and Testing Algorithm for Mismatch Repair–Defective Colorectal Carcinomas

Loss-of-function defects in DNA mismatch repair (MMR), which manifest as high levels of microsatellite instability (MSI), occur in approximately 15% of all colorectal carcinomas (CRCs). This molecular subset of CRC characterizes patients with better stage-specific prognoses who experience no benefit from 5-fluorouracil chemotherapy. Most MMR-deficient (dMMR) CRCs are sporadic, but 15% to 20% are due to inherited predisposition (Lynch syndrome). High penetrance of CRCs in germline MMR gene mutation carriers emphasizes the importance of accurate diagnosis of Lynch syndrome carriers. Family-based (Amsterdam), patient/family-based (Bethesda), morphology-based, microsatellite-based, and IHC-based screening criteria do not individually detect all germline mutation carriers. These limitations support the use of multiple concurrent tests and the screening of all patients with newly diagnosed CRC. This approach is resource intensive but would increase detection of inherited and de novo germline mutations to guide family screening. Although CRC prognosis and prediction of 5-fluorouracil response are similar in both the Lynch and sporadic dMMR subgroups, these subgroups differ significantly with regard to the implications for family members. We recommend that new CRCs should be classified into sporadic MMR-proficient, sporadic dMMR, or Lynch dMMR subgroups. The concurrent use of MSI testing, MMR protein IHC, and BRAF c.1799T>A mutation analysis would detect almost all dMMR CRCs, would classify 94% of all new CRCs into these MMR subgroups, and would guide secondary molecular testing of the remainder

Estructuras de datos y algoritmos eficientes para búsquedas web y procesamiento de grandes datos

Desde hace ya un par de décadas, la cantidad de información, las aplicaciones y el número de usuarios digitales crece exponencialmente, formando un ecosistema en el cual se intenta explotar la masividad de los datos y presentan a la comunidad científico/ tecnológica nuevos desafíos. Por ejemplo, los motores de búsqueda para la web son aplicaciones que procesan miles de millones de documentos para responder consultas de los usuarios. Esto genera nuevas necesidades de almacenamiento, procesamiento y búsquedas, expandiendo los límites del trabajo en una sola máquina y unos pocos algoritmos. Las consultas deben responderse en milisegundos, con resultados relevantes, sobre un escenario altamente heterogéneo. Además, el área de “Big Data”, que se aplica a cúmulos de datos que no pueden ser procesados y/o analizados de forma eficaz y eficiente utilizando técnicas tradicionales, aporta nuevos enfoques que complementan la idea anterior. En este proyecto se estudian, proponen, diseñan y evalúan estructuras de datos y algoritmos para soportar búsquedas de escala web y/o analizar datos masivos de forma eficiente.Eje: Bases de Datos y Minería de Datos.Red de Universidades con Carreras en Informátic

Relevance, Pathogenesis, and Testing Algorithm for Mismatch Repair–Defective Colorectal Carcinomas A Report of the Association for Molecular Pathology

Loss-of-function defects in DNA mismatch repair (MMR), which manifest as high levels of microsatellite instability (MSI), occur in approximately 15% of all colorectal carcinomas (CRCs). This molecular subset of CRC characterizes patients with better stage-specific prognoses who experience no benefit from 5-fluorouracil chemotherapy. Most MMR-deficient (dMMR) CRCs are sporadic, but 15% to 20% are due to inherited predisposition (Lynch syndrome). High penetrance of CRCs in germline MMR gene mutation carriers emphasizes the importance of accurate diagnosis of Lynch syndrome carriers. Family-based (Amsterdam), patient/family-based (Bethesda), morphology-based, microsatellite-based, and IHC-based screening criteria do not individually detect all germline mutation carriers. These limitations support the use of multiple concurrent tests and the screening of all patients with newly diagnosed CRC. This approach is resource intensive but would increase detection of inherited and de novo germline mutations to guide family screening. Although CRC prognosis and prediction of 5-fluorouracil response are similar in both the Lynch and sporadic dMMR subgroups, these subgroups differ significantly with regard to the implications for family members. We recommend that new CRCs should be classified into sporadic MMR-proficient, sporadic dMMR, or Lynch dMMR subgroups. The concurrent use of MSI testing, MMR protein IHC, and BRAF c.1799T>A mutation analysis would detect almost all dMMR CRCs, would classify 94% of all new CRCs into these MMR subgroups, and would guide secondary molecular testing of the remainder

Estructuras de datos y algoritmos eficientes para búsquedas web y procesamiento de grandes datos

Desde hace ya un par de décadas, la cantidad de información, las aplicaciones y el número de usuarios digitales crece exponencialmente, formando un ecosistema en el cual se intenta explotar la masividad de los datos y presentan a la comunidad científico/ tecnológica nuevos desafíos. Por ejemplo, los motores de búsqueda para la web son aplicaciones que procesan miles de millones de documentos para responder consultas de los usuarios. Esto genera nuevas necesidades de almacenamiento, procesamiento y búsquedas, expandiendo los límites del trabajo en una sola máquina y unos pocos algoritmos. Las consultas deben responderse en milisegundos, con resultados relevantes, sobre un escenario altamente heterogéneo. Además, el área de “Big Data”, que se aplica a cúmulos de datos que no pueden ser procesados y/o analizados de forma eficaz y eficiente utilizando técnicas tradicionales, aporta nuevos enfoques que complementan la idea anterior. En este proyecto se estudian, proponen, diseñan y evalúan estructuras de datos y algoritmos para soportar búsquedas de escala web y/o analizar datos masivos de forma eficiente.Eje: Bases de Datos y Minería de Datos.Red de Universidades con Carreras en Informátic

Molecular Biomarkers for the Evaluation of Colorectal Cancer

Objectives: To develop evidence-based guideline recommendations through a systematic review of the literature to establish standard molecular biomarker testing of colorectal cancer (CRC) tissues to guide epidermal growth factor receptor (EGFR) therapies and conventional chemotherapy regimens

Molecular Biomarkers for the Evaluation of Colorectal Cancer: Guideline From the American Society for Clinical Pathology, College of American Pathologists, Association for Molecular Pathology, and American Society of Clinical Oncology

OBJECTIVES: - To develop evidence-based guideline recommendations through a systematic review of the literature to establish standard molecular biomarker testing of colorectal cancer (CRC) tissues to guide epidermal growth factor receptor (EGFR) therapies and conventional chemotherapy regimens. METHODS: - The American Society for Clinical Pathology, College of American Pathologists, Association for Molecular Pathology, and American Society of Clinical Oncology convened an expert panel to develop an evidence-based guideline to establish standard molecular biomarker testing and guide therapies for patients with CRC. A comprehensive literature search that included more than 4,000 articles was conducted. RESULTS: - Twenty-one guideline statements were established. CONCLUSIONS: - Evidence supports mutational testing for EGFR signaling pathway genes, since they provide clinically actionable information as negative predictors of benefit to anti-EGFR monoclonal antibody therapies for targeted therapy of CRC. Mutations in several of the biomarkers have clear prognostic value. Laboratory approaches to operationalize CRC molecular testing are presented

Pattern-Selection Based Power Analysis and Discrimination of Low- and High-Grade Myelodysplastic Syndromes Study Using SNP Arrays

Copy Number Aberration (CNA) in myelodysplastic syndromes (MDS) study using single nucleotide polymorphism (SNP) arrays have been received increasingly attentions in the recent years. In the current study, a new Constraint Moving Average (CMA) algorithm is adopted to determine the regions of CNA regions first. In addition to large regions of CNA, using the proposed CMA algorithm, small regions of CNA can also be detected. Real-time Polymerase Chain Reaction (qPCR) results prove that the CMA algorithm presents an insightful discovery of both large and subtle regions. Based on the results of CMA, two independent applications are studied. The first one is power analysis for sample estimation. An accurate estimation of sample size needed for the desired purpose of an experiment will be important for effort-efficiency and cost-effectiveness. The power analysis is performed to determine the minimum sample size required for ensuring at least () detected regions statistically different from normal references. As expected, power increase with increasing sample size for a fixed significance level. The second application is the distinguishment of high-grade MDS patients from low-grade ones. We propose to calculate the General Variant Level (GVL) score to integrate the general information of each patient at genotype level, and use it as the unified measurement for the classification. Traditional MDS classifications usually refer to cell morphology and The International Prognostic Scoring System (IPSS), which belongs to the classification at the phenotype level. The proposed GVL score integrates the information of CNA region, the number of abnormal chromosomes and the total number of the altered SNPs at the genotype level. Statistical tests indicate that the high and low grade MDS patients can be well separated by GVL score, which appears to correlate better with clinical outcome than the traditional classification approaches using morphology and IPSS sore at the phenotype level