|New prostate cancer twice as effective as a PSA test could be available by next year.|
Scientists at the University of Surrey, UK, have made a major breakthrough in the early diagnosis of prostate cancer. They have developed a new way of detecting the cancer by testing a small urine sample from men, allowing faster testing that could save livs and off the potential of huge cost savings. The research was enabled by a close partnership between the University of Surrey and the Prostate Project.
A three-year study, published today in US journal Clinical Cancer Research, shows that a protein called Engrailed-2 (EN2) is made by prostate cancers and secreted into urine where it can be easily detected using the new test that is simple, quick and has the potential to be used in GP surgeries.
EN2 is an important protein in the development of the human embryo and, like many similar 'early life' proteins, its production is "switched off" at birth - but analysis of urine samples from 288 by the team at the University of Surrey found that EN2 is switched back on in prostate cancer.
Unlike the new EN2 test, the standard 30-year-old PSA test for prostate cancer involves taking a blood sample and is unable to detect a significant proportion of early prostate cancers, which go on to kill over 10,000 men in the UK every year. PSA tests can also result in "false positives" causing unnecessary worry.
The new EN2 test has been proven to be more reliable and accurate than existing tests, said Professor Hardev Pandha, The Prostate Project Chair of Urological Oncology at the University of Surrey's Postgraduate Medical School.
"In this study, we showed that the new test was twice as good at finding prostate cancer as the standard PSA test. Only rarely did we find EN2 in the urine of men who were cancer free, so if we find EN2 we can be reasonably sure that a man has prostate cancer. EN2 was not detected in men with non-cancer disorders of the prostate such as prostatitis or benign enlargement. These conditions often cause a high PSA result, causing considerable stress for the patient and sometimes also unnecessary further tests such as prostate biopsies."
With the current EN2 test, men provide a small urine sample either in the surgery or at home, which their doctor sends to the lab. Professor Pandha said the testing method could, in the near future, be made into an even simpler 'desktop' test that a family doctor could perform in their surgery. "The prospect of an immediate result that doesn't involve a blood test or an embarrassing examination may be helpful in getting more men with urinary symptoms to seek medical help", he added.
"Unlike the development of drug treatments, the time taken to verify the potential of EN2 in the diagnosis of prostate cancer is relatively modest," said co-researcher Dr Richard Morgan, Senior Lecturer in Molecular Oncology at the University of Surrey. "We are preparing several large studies in the UK and in the US and although the EN2 test is not yet available, several companies have expressed interest in taking it forward."
Patients were tested at St George's Hospital, University of London, Royal Surrey County Hospital, Guildford and Basingstoke Hospital.
Scientist, medical doctor and TV presenter Professor Robert Winston, who champions public engagement with science, said "This is an exciting discovery which advances the early detection of this cancer. It also shows just how vital the research carried out at Universities such as Surrey really is in helping to find faster, better solutions to some of the healthcare challenges that face us all."
Chairman of The Prostate Project Colin Stokes said: "We are all elated at this development. Huge credit must go to Professor Pandha, Dr Morgan and their outstanding team of researchers at the University of Surrey. I would like to thank everyone who has given their time and money so generously to our charity which has helped make today’s announcement possible. Some individuals and companies have been outstandingly generous. The charity is run entirely by volunteers and 98% of all the funds we raise for research go to the work at the University of Surrey and this has paid off handsomely. All our work over the last seven years has been geared to days like today - when we really do give men a better chance of beating prostate cancer."
Go to www.prostate-project.org.uk for more information
ABOUT CLINICAL CANCER RESEARCH
Clinical Cancer Research is a journal of the American Association for Cancer Research whose focus is to publish innovative clinical and translational cancer research studies that bridge the laboratory and the clinic. Clinical Cancer Research is especially interested in clinical trials evaluating new treatments, accompanied by research on pharmacology and molecular alterations or biomarkers that predict response or resistance to treatment.
How was this discovery made?
EN2 is one of a number of genes that has an important role in the development of the early embryo, and researchers at the University of Surrey are interested in the possible function of such genes in cancer. For this reason they looked to see whether EN2 is present in prostate cancer. When they
What is EN2?
EN2 is a protein that acts as an on-off switch for genes and as such has a key role in controlling the behaviour of cells.
Why is it better than existing tests?
The sensitivity (detecting the cancer if it’s there) and specificity (not detecting it if it's not there) are better than existing tests. It gives a far lower rate of false positives than the current PSA test and is therefore a more accurate diagnostic tool. It uses urine, which can be collected easily. Unlike some other urine based prostate tests it does not require stimulation of the prostate through a digital rectal examination. It tests for a molecule produced and released specifically by cancerous prostate cells as opposed to molecules released by the prostate when it is disturbed for a wide variety of reasons (as is the case with PSA). The link with cancer is clear and the function of the molecule is well understood. This is not the case in some other tests.
How accurate is it?
It detects between 60 and 70% of prostate cancers on its first use and rarely gives a positive result in patients with no prostatic disease. This is roughly twice as good as PSA. In only 4% of cases is a signal generated where cancer has not then been confirmed by a needle biopsy (which is however not infallible in itself). This is roughly 10 times as good as PSA.
Should I still see my GP if the test is negative?
Yes, if you have any symptoms that worry you such as discomfort in the prostate area or difficulty in urinating you should definitely see a GP. There are other conditions besides cancer that can affect the prostate which may not be caused by cancer but still require treatment.
If it is negative or positive, will I still need a PSA test?
The two tests complement each other. PSA remains the first and most important test to detect prostate cancer. We anticipate that this new test will ultimately complement PSA and the combination of the two tests will improve detection considerably. The PSA test is standard tool in the tracking the progress of prostate cancer, so if the EN2 is positive a PSA test will be recommended to establish base line for PSA tracking.
Will this lead to National Screening?
This is one possibility, yes. The performance of the test is now better than the screening methods for cervical and breast cancer.