Could a novel epigenetic immunoassay revolutionise the detection of colorectal cancer?
- Capacity for colonoscopies is under strain and increased waiting time could lead to fewer patients being diagnosed early
- VolitionRx’s blood-based test ‘NuQTM’ could ease capacity issues, potentially detecting more cases of colorectal cancer (CRC) due to higher patient throughput
- The test could be a cost-effective method that avoids unnecessary invasive procedures
It’s where ‘Epigenetics meets oncology,’ VolitionRx stated when describing their recently developed test, NuQTM, an epigenetic immunoassay for the detection of CRC. Results presented at the 2016 European Society for Medical Oncology Congress suggest that the method could reduce capacity pressures for colonoscopies and, possibly, detect more CRC cases early due to a higher throughput of patients.
“The combination of NuQTM assays associated with a FIT score could lead to a reduction in 25% of unnecessary colonoscopies.”
Dr Marielle Herzog, Lead Scientist, VolitionRx
In Europe, “CRC is responsible for more than 200,000 deaths per year,” explained Dr Marielle Herzog, Lead Scientist at VolitionRx. The early detection of CRC, however, can save both lives and healthcare costs.
The current method of detection is using a faecal immune test (FIT) to indicate patients likely to have CRC, proceeding then to a colonoscopy for confirmation. Using colonoscopies as a method for detecting CRC, although accurate, is invasive and expensive, and increased waiting times for the test could affect the number of patients diagnosed early.
The NuQTM test developed by VolitionRx uses blood-based diagnostic testing for cancer, which can be detectable due to epigenetic changes. Epigenetics is the switching ‘on’ or ‘off’ of genes by the chemical modification of proteins called histones, in which DNA is wrapped tightly around. These modifications remodel nucleosomes, the structural unit of a chromosome formed by the DNA and histones.
“Nucleosomics is a technological platform that Volition has developed,” Dr Herzog explained, “the NuQTM test identifies and measures circulating nucleosome structures for the presence of epigenetic cancer signals within the blood.”
It is well known that cancer has a genome-wide effect on the epigenetics of the afflicted cell. High cell turnover, due to the rapid growth of cancer cells, means that a dramatic excess of fragments – including nucleosomes – are released into the blood.
This has allowed VolitionRx to develop a method of detection using an enzyme-linked immunosorbent assay (ELISA) to test for circulating nucleosomes. It is important to note that nucleosomes originating from cancer cells have different epigenetic markers to healthy cells. These can be identified by particular histone modifications or variants or DNA modifications (including methylation or protein adducts).
The VolitionRx laboratory in Belgium collaborated with the Hvidovre Hospital, University of Copenhagen, in order to evaluate the use of a FIT score with a NuQTM test for the detection of CRC. Serum samples were collected from 1,907 FIT positive patients with previous confirmation of CRC by colonoscopy. 10 mcL serum samples were analysed using NuQTM ELISA tests and an algorithm using linear discriminant analysis was developed to identify patients showing no evidence of cancer.
The results showed that “the combination of NuQTM assays associated with a FIT score could lead to a reduction in 25% of unnecessary colonoscopies.” This reduction, the team found, is associated with 96.6% sensitivity for CRC and 88.5% sensitivity for high-risk adenoma. Using a FIT score with the NuQTM test meant that 34 more cases of CRC were detected compared to a using FIT screening program, a 29% increase.
The test has the potential to reduce unnecessary colonoscopy procedures, easing current problems with capacity, and perhaps increasing the early detection of CRC.
“We clearly improved the screening program for CRC and may also lead to better compliance by the person,” Dr Herzog says. The NuQTM CRC triage test will be available for use in 2017.
Based on Herzog M, Eccleston M et al. A novel epigenetic immunoassay approach to profiling circulating nucleosomes for CRC detection (LBA23_PR). Presented on Monday 10 October 2016.
[button link=“https://medonline.at/infocenter-esmo/“ color=“blue“ target=“blank“ size=“large“]<< Back to Infocenter ESMO 2016[/button]