80% Detection Rate in Prostate Cancer Cases
Blog Mar 27, 2014
VolitionRx recently announced data from a pilot study into the utility of VolitionRx’s NuQ® tests to diagnose prostate cancer which showed that the assays were able to detect approximately 80% of prostate cancer cases.
The tests were not only shown to have a high detection rate for prostate cancer, but also to differentiate between colorectal (CRC) and prostate cancer.
We spoke to Dr. Jake Micallef, Chief Scientific Officer at VolitionRx, to understand more about the NuQ® assay and the results of this study.
AB: Can you explain how the NuQ® assay detects cancer?
Jake Micallef (JM): NuQ is short for Nucleosome Quantification.
Our cells contain the chromosomes that contain our DNA and genes. These chromosomes are made up of nucleosomes (in the same way that starch is made of glucose). Each of our 46 chromosomes is essentially a coiled up string of about half a million nucleosomes arranged like beads on a string where the string is the DNA, as shown in the image below.
Volition’s NuQ assays represent a combination of two independent lines of cancer research that have each been going on since the year 2000. The first line has shown that the chromosomes and nucleosomes in cancer cells have different chemical structures to those in healthy people. The second has shown that nucleosomes from dead cancer cells are present in the blood of cancer patients. Our NuQ tests detect these altered nucleosomes in the blood of cancer patients to detect the cancer.
AB: Did you anticipate detection rates of 80% for prostate cancer cases or did this exceed expectations?
JM: The results did exceed my expectations – but I am very happy! However, there is still a lot of work to do. For example, an ideal prostate cancer test would detect only aggressive prostate cancer cases that require treatment. The current PSA test detects many cancers which do not require treatment leading to many unnecessary painful prostate biopsies.
AB: Was the assay also developed to distinguish the types of cancer or was this an unexpected result?
JM: The two reasons for doing the prostate study were firstly to see if the NuQ tests would detect prostate cancer and secondly to see whether it would be possible to distinguish between the two cancer types.
The result was very exciting – the ability to distinguish between people with prostate cancer and colon cancer shows that, with the right panel combination, NuQ assays can distinguish between different types of cancer as well as healthy samples. This is just what we’ve been working towards. Colorectal and prostate cancers may be just the start.
AB: How do these results compare to other tests on the markets (if they exist)?
JM: The competing test for colorectal cancer is the Feacal Occult Blood Test or the Faecal Immunochemical Test. The mortality rate for colorectal cancer has fallen in the UK with the introduction of faecal screening tests for people aged over 60, but less than half of all cancers are detected because only about half of the people sent a faecal test actually do it. This is because three faecal samples must be taken following three days of pre-test preparation and some people find faecal sampling distasteful. Research, including our own survey, shows that up to 97% of people will take a blood test so there is a potential for a great improvement in CRC detection rate and survival rates with a CRC blood test.
AB: Now you have presented the results, what is the next stage?
JM: The next steps are to confirm the results in a larger study and we are currently part way through a blind clinical study in a much larger number of patients - 4800 symptomatic patients referred for colonoscopy with Hvidovre Hospital Copenhagen. This will provide incontrovertible evidence of the clinical utility of NuQ assays in colorectal cancer and be will be used as part of the necessary evidence for regulatory approval for the assays in Europe.
We are also embarking next month on an 11,000 prospective patient screening CRC study – also with Hvidovre Hospital in Copenhagen.