Professor Mark Emberton
Dean of Faculty of Medical Sciences
Studies show that novel biomarkers are making prostate cancer diagnosis more accurate and effective — which means fewer men will undergo unnecessary biopsies in future.
Prostate cancer isn’t easy to diagnose. Historically, diagnosis has largely been driven by a prostate examination, a PSA test (which measures the levels of Prostate Specific Antigen in the blood), and a likely further investigation via an invasive biopsy. However, this practice has become old fashioned, and we are in need of a more accurate, less invasive solution that detects only the tumours that need detecting, and doesn’t detect those that are not clinically significant.
The term ‘biomarker’ – a measurable indicator of the presence, activity or likely course of a disease – is one that’s becoming increasingly familiar in oncology. PSA is a biomarker that acts as a proxy for the likely course of disease. MRI scanning is a biomarker that allows us to visualise how the disease has manifested itself. And genetic biomarkers are moving increasingly to the fore as binary indicators of clinically significant disease.
Biomarkers play unique roles in the detection of disease
Ninety per cent of urologists will now offer patients with elevated PSA an MRI scan, which has been a brilliant development towards improved diagnosis. According to Mark Emberton, Professor of Interventional Oncology at University College London (UCL), “MRI scanning can double the detection of clinically significant disease and lower the detection of insignificant disease,’’ but there remain instances where use of MRI is not possible, or where the results are indeterminate. That’s when a reliable ‘companion’ biomarker is useful. Equally, according to Professor Emberton, we are in need of something better than PSA to determine who is eligible for further tests – these are what we call ‘triage’ biomarkers.
Not all tumours need detection
We are in an age of constant research and developments, and many say that it’s an exciting time for medicine, but with 10,000 men still dying from prostate cancer each year, there is still lots to be done.
Clearly, early detection is important, but so is the right kind of detection, stresses Professor Emberton, because over-diagnosis can be harmful to patients. “This type of cancer is so prevalent that testing needs to be more sophisticated than just finding tumours,” and that could be where we rely on novel biomarkers to improve accuracy and reduce scope for misinterpretation.
Paving the way for a national screening programme
“The next challenge is one of implementation so that all men, globally, have access to high quality screening,” Professor Emberton says. “Most of the screening scandals that occur are because of poor quality screening in what is a very complex intervention. It’s a very complex pathway and if you don’t get everything right, you’ll miss out on those few patients whose lives you could have prolonged.”
Soon, a country-wide prostate screening programme could be possible in the same way that breast cancer screening is available to women over 50, and it’s an area being led by the NHS and UK medicine. The MRC and CRUK have funded a study called ‘Re-imagine’, which will test possible new screening techniques including the biomarkers earlier alluded to. Dubbed a ‘hugely important’ study by Professor Emberton, results won’t be available for a couple of years, but it could pave the way to revolutionising our ability to screen for, and therefore more effectively treat prostate cancer.