Ovarian cancer and the evolution of subtype classifications using transcriptional profiling†.

Ovarian cancer is a complex disease with multiple subtypes, each having distinct histopathologies and variable responses to treatment. This review highlights the technological milestones and the studies that have applied them to change our definitions of ovarian cancer. Over the past 50 years, technologies such as microarrays and next-generation sequencing have led to the discovery of molecular alterations that define each of the ovarian cancer subtypes and has enabled further subclassification of the most common subtype, high-grade serous ovarian cancer (HGSOC). Improvements in mutational profiling have provided valuable insight, such as the ubiquity of TP53 mutations in HGSOC tumors. However, the information derived from these technological advances has also revealed the immense heterogeneity of this disease, from variation between patients to compositional differences within single masses. In looking forward, the emerging technologies for single-cell and spatially resolved transcriptomics will allow us to better understand the cellular composition and structure of tumors and how these contribute to the molecular subtypes. Attempts to incorporate the complexities ovarian cancer has resulted in increasing sophistication of model systems, and the increased precision in molecular profiling of ovarian cancers has already led to the introduction of inhibitors of poly (ADP-ribose) polymerases as a new class of treatments for ovarian cancer with DNA repair deficiencies. Future endeavors to define increasingly accurate classification strategies for ovarian cancer subtypes will allow for confident prediction of disease progression and provide important insight into potentially targetable molecular mechanisms specific to each subtype.

International network of cancer genome projects.

The International Cancer Genome Consortium (ICGC) was launched to coordinate large-scale cancer genome studies in tumours from 50 different cancer types and/or subtypes that are of clinical and societal importance across the globe. Systematic studies of more than 25,000 cancer genomes at the genomic, epigenomic and transcriptomic levels will reveal the repertoire of oncogenic mutations, uncover traces of the mutagenic influences, define clinically relevant subtypes for prognosis and therapeutic management, and enable the development of new cancer therapies.

HBOC multi-gene panel testing: comparison of two sequencing centers.

Multi-gene panels are used to identify genetic causes of hereditary breast and ovarian cancer (HBOC) in large patient cohorts. This study compares the diagnostic workflow in two centers and gives valuable insights into different next-generation sequencing (NGS) strategies. Moreover, we present data from 620 patients sequenced at both centers. Both sequencing centers are part of the German consortium for hereditary breast and ovarian cancer (GC-HBOC). All 620 patients included in this study were selected following standard BRCA1/2 testing guidelines. A set of 10 sequenced genes was analyzed per patient. Twelve samples were exchanged and sequenced at both centers. NGS results were highly concordant in 12 exchanged samples (205/206 variants = 99.51 %). One non-pathogenic variant was missed at center B due to a sequencing gap (no technical coverage). The custom enrichment at center B was optimized during this study; for example, the average number of missing bases was reduced by a factor of four (vers. 1: 1939.41, vers. 4: 506.01 bp). There were no sequencing gaps at center A, but four CCDS exons were not included in the enrichment. Pathogenic mutations were found in 12.10 % (75/620) of all patients: 4.84 % (30/620) in BRCA1, 4.35 % in BRCA2 (27/620), 0.97 % in CHEK2 (6/620), 0.65 % in ATM (4/620), 0.48 % in CDH1 (3/620), 0.32 % in PALB2 (2/620), 0.32 % in NBN (2/620), and 0.16 % in TP53 (1/620). NGS diagnostics for HBOC-related genes is robust, cost effective, and the method of choice for genetic testing in large cohorts. Adding 8 genes to standard BRCA1- and BRCA2-testing increased the mutation detection rate by one-third.

Next generation sequencing and tumor mutation profiling: are we ready for routine use in the oncology clinic?

Next generation sequencing (NGS) coupled with sophisticated bioinformatics tools yields an unprecedented amount of information regarding tumor genetics, with the potential to reveal insights into tumor behavior. NGS and other multiplex genomic assays are rapidly spilling from the laboratory into the clinic through numerous commercial and academic entities. This raises the important question as to whether we are ready to use these data in clinical decision-making. While genetic lesions are clearly targeted by a new generation of biological cancer therapies, and certain regulatory approvals are actually coupled to single gene assays, we still do not know if the vast information on other genomic alterations is worth the added cost, or even worse, the inappropriate and unproven assignment of patients to treatment with an unapproved drug carrying potentially serious side effects. On the other hand, the trend toward a precision medicine pathway is clearly accelerating, and clinical trials validating pathway-driven personalized cancer therapeutics will be necessary in both the community and academic settings. Lower cost and wider availability of NGS now raises a debate over the merit of routine tumor genome-wide analysis.

EGFR mutation testing practice in advanced non-small cell lung cancer.

PURPOSE: Testing tumor samples for the presence of a mutation in the epithelial growth factor receptor (EGFR) gene is recommended for advanced non-squamous non-small cell lung cancer (NSCLC) patients. We aimed to collect data about common practice among Medical Oncologists treating lung cancer patients, regarding EGFR mutation testing in advanced NSCLC patients. METHODS: An internet-based survey was conducted among members of the Israeli Society for Clinical Oncology and Radiotherapy involved in the treatment of lung cancer patients. RESULTS: 24 Oncologists participated in the survey. The participants encompass the Oncologists treating most of the lung cancer patients in Israel. 79% of them use EGFR testing routinely for all advanced NSCLC patients. Opinions were split regarding the preferable biopsy site for EGFR testing material. 60% of participants recommend waiting for EGFR test results prior to initiation of first-line therapy. CONCLUSIONS: EGFR testing is requested in Israel routinely by most treating Oncologists for all advanced NSCLC patients, regardless of histology. In most cases, systemic treatment is deferred until the results of this test are received.

[Molecular pathology of the lungs. New perspectives by next generation sequencing]. / Molekularpathologie der Lunge. Perspektiven durch neue Sequenzierformen.

Lung cancer is one of the most frequent malignancies in the western world. Its frequent association with a wide spectrum of mutations in genes encoding various signal transducers that are often linked to therapy response, emphasizes the obvious need for improved, fast and highly efficient approaches in molecular pathology. Comprehensive analyses of the mutation status of progression and therapy relevant genes can be performed by the novel sequencing forms named next generation sequencing (NGS) providing extremely high capacities for ultra-deep sequence analyses. The 454 pyrosequencing method, the sequencing by synthesis and the semiconductor sequencing platform are now available for parallel sequencing approaches of multitudinous target genes linked to multiple tumor DNA applications. The "one molecule, one clone, one read" principle by the NGS approaches supplies not only information on allele frequencies and mutation rates but also has the advantage of a very sensitive detection of low frequency variants.

Santorini mutation detection meeting 2011: rapid advance in sequencing technology poses challenges for interpretation of genetic variations.

The 11th International Symposium on Mutations in the Genome was held on 6-10 June, 2011, in Santorini, Greece. Meeting participants described novel detection technologies, rapid advances in whole genome and whole-exome sequencing, but also highlighted the urgent need for the development of sequence variation databases and the clinical interpretation of the genomic data. This report summarizes some of the major themes presented during the meeting.

Molecular targeted therapy in lung cancer.

Genetic sequencing has allowed better understanding of non-small-cell lung cancer, leading to improvements in the ability to diagnose and treat the disease through targeted therapy. This article describes some of the past and ongoing studies of targeted therapies for lung cancers, the genetic mutations in lung cancers that develop in people who never smoked, and the role of Minnesota researchers in understanding the pathogenesis of lung cancer.

Genetics of Parkinson disease and essential tremor.

PURPOSE OF REVIEW: Elucidating the genetic background of Parkinson disease and essential tremor is crucial to understand the pathogenesis and improve diagnostic and therapeutic strategies. RECENT FINDINGS: A number of approaches have been applied including familial and association studies, and studies of gene expression profiles to identify genes involved in susceptibility to Parkinson disease. These studies have nominated a number of candidate Parkinson disease genes and novel loci including Omi/HtrA2, GIGYF2, FGF20, PDXK, EIF4G1 and PARK16. A recent notable finding has been the confirmation for the role of heterozygous mutations in glucocerebrosidase (GBA) as risk factors for Parkinson disease. Finally, association studies have nominated genetic variation in the leucine-rich repeat and Ig containing 1 gene (LINGO1) as a risk for both Parkinson disease and essential tremor, providing the first genetic evidence of a link between the two conditions. SUMMARY: Although undoubtedly genes remain to be identified, considerable progress has been achieved in the understanding of the genetic basis of Parkinson disease. This same effort is now required for essential tremor. The use of next-generation high-throughput sequencing and genotyping technologies will help pave the way for future insight leading to advances in diagnosis, prevention and cure.

Harnessing the full potential of reproductive genetics and epigenetics for male infertility in the era of "big data".

The complexity of male reproductive impairment has hampered characterization of the underlying genetic causes of male infertility. However, in the last 20 years, more powerful and affordable tools to interrogate the genetic and epigenetic determinants of male infertility have accelerated the number of new discoveries in the characterization of male infertility. With this explosion of new data, integration in a systems-based approach-including complete phenotypic information-to male infertility is imperative. We briefly review the current understanding of genetic and epigenetic causes of male infertility and how findings may be translated into a practical component for the diagnosis and treatment of male infertility.

An overview of 20 years of genetic studies in pheochromocytoma and paraganglioma.

Paragangliomas and pheochromocytomas (PPGL) are rare neuroendocrine tumours characterized by a strong genetic determinism. Over the past 20 years, evolution of PPGL genetics has revealed that around 40% of PPGL are genetically determined, secondary to a germline mutation in one of more than twenty susceptibility genes reported so far. More than half of the mutations occur in one of the SDHx genes (SDHA, SDHB, SDHC, SDHD, SDHAF2), which encode the different subunits and assembly protein of a mitochondrial enzyme, succinate dehydrogenase. These susceptibility genes predispose to early forms (VHL, RET, SDHD, EPAS1, DLST), syndromic (RET, VHL, EPAS1, NF1, FH), multiple (SDHD, TMEM127, MAX, DLST, MDH2, GOT2) or malignant (SDHB, FH, SLC25A11) PPGL. The discovery of a germline mutation in one of these genes changes the patient's follow-up and allows genetic screening of affected families and the presymptomatic follow-up of relatives carrying a mutation.

Cushing syndrome: Old and new genes.

Cushing syndrome (CS) describes the signs and symptoms caused by exogenous or endogenous hypercortisolemia. Endogenous CS is caused by either ACTH-dependent sources (pituitary or ectopic) or ACTH-independent (adrenal) hypercortisolemia. Several genes are currently known to contribute to the pathogenesis of CS. Germline gene defects, such as MEN1, AIP, PRKAR1A and others, often present in patients with pituitary or adrenal involvement as part of a genetic syndrome. Somatic defects in genes, such as USP8, TP53, and others, are also involved in the development of pituitary or adrenal tumors in a large percentage of patients with CS, and give insight in pathways involved in pituitary or adrenal tumorigenesis.

Evolving Significance of Tumor-Normal Sequencing in Cancer Care.

Molecular tests assist at various stages of cancer patient management, including providing diagnosis, predicting prognosis, identifying therapeutic targets, and determining hereditary cancer risk. The current testing paradigm involves germline testing in a subset of patients determined to be at high risk for having a hereditary cancer syndrome, and tumor-only sequencing for treatment decisions in advanced cancer patients. A major limitation of tumor-only sequencing is its inability to distinguish germline versus somatic mutations. Tumor-normal sequencing has emerged as a comprehensive analysis for both hereditary cancer predisposition and somatic profiling. Here, we review recent studies involving tumor-normal sequencing, discuss its benefits in clinical care, challenges for its implementation, and novel insights it has provided regarding tumor biology and germline contribution to cancer.

Regulatory perspectives on next-generation sequencing and complementary diagnostics in Japan.

INTRODUCTION: The 'one biomarker/one drug' scenario is unsustainable because cancer is a complex disorder that involves a number of molecular defects. In the past decade, major technological advances have lowered the overall cost and increased the efficiency of next-generation sequencing (NGS). AREAS COVERED: We review recent regulations on NGS and complementary diagnostics in Japan, mainly focusing on high-quality studies that utilized these new diagnostic modalities and were published within the last 5 years. We highlight significant changes in regulation, and explain the direction of efforts to translate the results of NGS and complementary diagnostics into clinical practice. EXPERT OPINION: NGS holds a number of advantages over conventional companion and complementary diagnostics that enable simultaneous analyzes of multiple cancer genes to detect actionable mutations. Parallel technological developments and regulatory changes have led to the rapid adoption of NGS into clinical practice. NGS-based genomic data have been leveraged to better understand the characteristics of a disease that affects its patient's response to a given therapy. As NGS-based tests become more widespread, however, Japanese authorities will face significant challenges particularly with respect to the complexity of genomic data, which will have to be managed if NGS is to benefit patients.

Is it necessary to identify molecular defects in primary immunodeficiency disease?

The identification of the molecular bases of more than 130 primary immunodeficiency diseases has prompted the use of mutation analysis in the diagnostic approach to these patients. Here we discuss the importance of and the limitations associated with molecular diagnosis of these disorders and emphasize the need that mutation analysis be accompanied by appropriate evidence that the identified genetic defect has pathologic consequences on RNA/protein expression and function.

Defining the blueprint of the cancer genome.

It is widely accepted that cancer is a disease caused by accumulation of mutations in specific genes. These tumor-specific mutations provide clues to the cellular processes underlying tumorigenesis and have proven useful for diagnostic and therapeutic purposes. To date, however, only a small fraction of genes has been analyzed and the number and type of alterations responsible for the development of common tumor types are unknown. The determination of the human genome sequence coupled with improvements in sequencing and bioinformatic approaches have made it possible to examine the cancer cell genome in a comprehensive and unbiased manner. Systematic sequencing studies have been performed on gene families involved in signal transduction in several tumor types, and have now been extended to include the majority of protein-coding genes in breast and colorectal cancers. These analyses have identified new genes and pathways that had not been linked previously to human cancer. One example has been the discovery of genetic alterations in the PIK3CA gene encoding p110alpha phosphatidylinositol 3-kinase and in related pathway genes in >30% of colon and breast cancers. These mutational analyses provide a window into the genetic landscape of human cancer, indicate new targets for personalized diagnostic and therapeutic intervention, and suggest lessons for future large-scale genomic analyses in human tumors.

Forensically relevant SNP classes.

Forensic samples that contain too little template DNA or are too degraded require alternate genetic marker analyses or approaches to what is currently used for routine casework. Single nucleotide polymorphisms (SNPs) offer promise to support forensic DNA analyses because of an abundance of potential markers, amenability to automation, and potential reduction in required fragment length to only 60-80 bp. The SNP markers will serve an important role in analyzing challenging forensic samples, such as those that are very degraded, for augmenting the power of kinship analyses and family reconstructions for missing persons and unidentified human remains, as well as for providing investigative lead value in some cases without a suspect (and no genetic profile match in CODIS). The SNPs for forensic analyses can be divided into four categories: identity-testing SNPs; lineage informative SNPs; ancestry informative SNPs; and phenotype informative SNPs. In addition to discussing the applications of these different types of SNPs, this article provides some discussion on privacy issues so that society and policymakers can be more informed.

Molecular diagnosis of HIV and relevant novel technologies in mutation analysis.

HIV infection is one of the major threats to human health due to the lack of relevant vaccine and drugs to cure AIDS. Its early diagnosis is thus important in controlling HIV transmission. Molecular diagnosis of HIV can be performed qualitatively and quantitatively. Currently, molecular diagnosis of HIV infection is only used as a complementary diagnosis although viral load test is used to monitor disease progression and responsiveness to antiviral therapy. To optimize HIV assays, a variety of technological advances, such as the introduction of dUTP/UNG system, real-time detection platform, and coupling of more than one enzyme in molecular identification, have been integrated into new methods. With the development of more reliable HIV assays in the future, the molecular diagnosis of HIV is expected to be accepted as one of the standards in determining whether there is a HIV infection in resource-rich laboratories, which will play a crucial role in reducing HIV transmission.