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Cancer Diagnostics: A 2016 Update

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An overview of new developments in the field of cancer diagnostics

1 Feb 2016
Sonia Nicholas
Managing Editor and Clinical Lead

Editorial article

For many patients, an early diagnosis means a prolonged survival time

Never before has so much money, time and expertise gone into cancer research. Science moves quickly and there are some really exciting new developments on the horizon for cancer diagnostics. This article looks at three main areas of interest regarding in vitro diagnostics, next generation sequencing, liquid biopsies and volatile breath analysis.

Early diagnosis

The benefits of being able to diagnose cancers at an earlier stage are significant. Put simply, the earlier a cancer is detected, the earlier it can be treated and prevented from spreading. For many patients, an early diagnosis means a prolonged survival time. Once a cancer has grown very large, or has spread from the primary site, patients typically face a poorer prognosis.

Diagnostic research

Cancer diagnostics currently rely heavily on invasive biopsies to confirm tumor type and to determine a treatment plan. Invasive biopsies are not always a practical option due to tumor location and the frailty and age of the patient. It is also now known that tumor composition and genetic make-up varies widely, even in a single tumor – so testing one biopsy site doesn’t provide you with an accurate overview of the tumor as a whole1.

There are three significant research approaches to improving in vitro cancer diagnostics.

Improving knowledge

An improved knowledge of how tumors form and grow is key to being able to identify biomarkers that are associated with the early stages of cancer. Cancer researchers have traditionally used Sanger sequencing to improve their understanding of the molecular basis of cancer; however the increasing application of next generation sequencing (NGS) to cancer diagnostics offers the potential to simultaneously screen for multiple mutations, giving a much greater understanding of the disease.

NGS is a technology in which millions or billions of DNA strands can be sequenced in parallel. NGS yields much more genetic data than Sanger sequencing, allowing an entire genome to be sequenced in as little as a day. This allows researchers to look at huge amounts of genetic data and to analyze shared mutations in genes that lead to disease.

Next generation sequencing allows millions of DNA strands to be sequenced in parallel yielding huge amounts of genetic data

Further advantages of using NGS over traditional Sanger sequencing for cancer diagnostics include the requirement for less DNA (a particular advantage when using fixed-tissue tumor samples), its speed of analysis (it is significantly faster) and it’s increasing cost-effectiveness.

Perhaps more than any other technology, NGS has the potential to unlock the true power of personalized medicine. NGS could allow clinicians to understand an individual patients genetic make-up, pinpoint the molecular aberrations that have driven their disease and determine what course of therapy is likely to be most effective.

Current market leaders in clinical oncology-related NGS include Illumina with the high-throughput DNA sequencing system, the MiSeqDx® System, QIAGEN’s new NGS GeneReader platform and the Life Technologies Ion PGM Dx System.

Liquid biopsies

The ‘holy grail’ of cancer diagnostics is the possibility of being able to diagnose cancer using a simple blood test, without the need for an invasive biopsy. It is now known that tumors release DNA into the blood stream of the patient. Liquid biopsies are blood tests that can analyze this circulating DNA, if the form of cell-free tumor DNA (cfDNA), circulating tumor cells (CTC’s) or exosomes in the patient’s blood, to give a true representation of that patients molecular profile.

An example of the effective use of ‘liquid biopsies’ was highlighted in 2013 in a paper published by Nature, featuring work undertaken by the Cancer Research UK Cambridge Institute and University of Cambridge2. In the paper the authors describe how the use of exome sequencing enabled them to analyze circulating DNA and take a snapshot of the genetic errors in patients with breast cancer.

Since then, numerous studies have been undertaken on potential liquid biopsies3, including a recent trial involving EKF’s PointManTM enrichment technology. The levels of detectable cfDNA in the blood vary considerably. One of the problems associated with liquid biopsies is their lack of ability to detect cfDNA in the blood when they are very low. PointManTM technology is able to amplify a target sequence of interest allowing researchers to detect these low level cancer mutations.

EKF's PointMan™ DNA Enrichment Kits allow researchers to amplify specific mutation sequences

Liquid biopsies have the potential to add significant value to cancer patients and to further propel us towards the goal of personalized medicine. In the near future, these tests might replace invasive biopsies to detect and monitor cancerous tumors, and could be used to identify tumors not yet visible with imaging techniques.

Volatile breath analysis

Volatile organic compounds (VOCs) are detectable in the breath in very low concentrations. Examples of VOC’s measurable in exhaled breath include alcohols, ketones and organic sulphides. Because the detectable levels are very low, analytical mass spectrometry is usually required to analyse the breath samples.

VOC breath analysis is an area of increasing interest in cancer diagnosis. It has been found that different VOC breath patterns can be correlated to various different diseases. VOC patterns have been identified in lung cancer4,5, colorectal & prostate cancer6, and breast cancer7.

Analysis of breath biomarkers is in its infancy and much more work needs to be undertaken in this field. Initially, large scale studies need to be carried out to determine normal VOC patterns before diagnostic biomarkers can be reliably identified.

Find out more about cancer research on our dedicated cancer diagnostics community page.

References:

http://www.nejm.org/doi/full/10.1056/NEJMoa1113205

http://scienceblog.cancerresearchuk.org/2013/03/13/blood-test-tracks-breast-cancer/

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4356857/

http://www.lungcancerjournal.info/article/S0169-5002(09)00208-6/abstract

http://www.sciencedirect.com/science/article/pii/S1570023210000383

http://www.nature.com/bjc/journal/v103/n4/full/6605810a.html

http://www.ncbi.nlm.nih.gov/pubmed/23383557

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HematologyIn Haematology / Hematology, complete blood cell counts (or full blood counts) are obtained using automated blood count analyzers to enumerate blood cell types.  Hematology also encompasses haemostasis and coagulation, thrombophilia and hemophilia, plasma viscosity and ESR analysis, hemoglobinopathies, cell morphology and haematinic measurement.ImmunologyImmunological techniques measure and characterize immune responses. Immunology kits and analysis systems often use techniques such as ELISA, radioimmunoassay (RIA) and immunodiffusion assays, Immunohistochemistry, and flow cytometry. Immunologists use equipment such as flow Cytometers, plate readers, plate washers and fluorescent microscopes.Cellular PathologyCellular Pathology deals with the microscopic analysis of tissue samples and cells. Sample preparation and processing includes fixation, staining, sectioning and slide mounting, using equipment such microtomes and cryostats. In choosing immunohistochemistry and immunocytochemistry kits, consider chromogens, staining method, antibodies, microscopes and imaging.Cell-Based AssaysCell-based assays are used to monitor the presence, quantity and activities of a desired cellular analyte including drug molecules or biomarkers. This can reveal information on cell health (apoptosis, cytotoxicity, viability and proliferation assays), cell metabolism, cell migration and cell signaling mechanisms. Find the best cell-based assay products, kits and equipment with our peer reviewed product directory: compare products, check customer reviews and receiving pricing direct from manufacturers.Point-of-CarePoint-of-Care Testing (POCT) or Near Patient Testing (NPT) products are available for urine, blood and other clinical chemistry analyses. POCT includes: blood glucose testing, blood gas and electrolytes analysis, rapid coagulation testing (PT / INR), rapid cardiac markers diagnostics, drugs of abuse screening, urine strips testing, pregnancy testing, fecal occult blood analysis, food pathogens screening, hemoglobin diagnostics, infectious disease testing and cholesterol screening.Clinical ChemistryBiochemistry (or clinical chemistry) involves the analysis of bodily fluids using chemical tests. Techniques used include HPLC, chromatography, spectroscopy, mass spectrometry, immunochemical, electrophoresis, turbidometric / spectrophotometric assay, MRI and ISE analysis. Tests are often carried out on plasma or serum but urine (urinalysis) and fecal specimens are also processed.Clinical GeneticsMolecular Genetics covers the analysis of hereditary genetic disease and chromosomal abnormalities. Genetics can be analysed using DNA, RNA, and protein microarrays, PCR, RT PCR and DNA sequencing. Genetic equipment includes genetic workstations, thermal cyclers, cooling blocks and electrophoresis products. Diagnostic kits are used for DNA / RNA extraction and purification.Next Generation SequencingNext-generation sequencing (NGS), also known as whole-genome sequencing, high-throughput sequencing and massive parallel sequencing, produces and analyses thousands to millions of nucleotide sequences at once. Sequencing systems operate via varying technologies depending on the manufacturer, including sequencing by synthesis, ligation, pyrosequencing, ion semiconductor and single-molecule real-time sequencing. For NGS, library preparation is paramount to successful sequencing. In this section, explore a range of library preparation kits, from targeted, amplicon-based or hybridization-based kits including epigenomic, transcriptomic and genomic workflows to fragmentation kits. Find the best next-generation sequencing products in our peer-reviewed product directory: compare products, check customer reviews and receive pricing direct from manufacturers.Cancer DiagnosticsThere are a wide variety of diagnostic tests for cancer available, and this range continues to expand as our knowledge of cancer improves. Current diagnostic methods include biopsy, imaging and blood tests for known biomarkers. New methods in research development include liquid biopsies and cancer breathalyzers.Clinical NGSNext Generation Sequencing (NGS) refers to the use of massive parallel sequencing of multiple small fragments of DNA. This high-throughput genomic analysis yields enormous amounts of sequence data, which if appropriately analyzed could have huge potential for clinical laboratories. For this to happen there are technique and bioinformatic hurdles to be overcome.Liquid BiopsiesLiquid biopsies are non-invasive tests used to detect cancer and other diseases by analyzing blood or other bodily fluids. This technique is gaining popularity for early detection, monitoring treatment response, and detecting minimal residual disease. Explore liquid biopsy solutions in our peer-reviewed product directory; compare products, check reviews, and get pricing directly from manufacturers.Cancer ResearchAlthough cancer is often referred to as a single condition, it actually consists of more than 100 different diseases. Microscopy, mass spectrometry, high throughput sequencing and flow cytometry are some of the most common techniques employed in cancer research labs.

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