UK scientists say a new screening technique called ‘Prostagram’ could catch an extra 40,000 prostate cancer cases a year.
The non-invasive, 15-minute scan is based on magnetic resonance imaging (MRI), which uses strong magnetic fields and radio waves to produce detailed images of the inside of the body.
Prostagram is modelled on breast cancer screening, where women are routinely offered a mammogram scan every three years as part of a national programme.
This breast cancer screening is credited with saving some 1,300 lives a year, reducing the death toll by more than 10 per cent, and it’s hoped similar results will be seen with Prostagram.
The new scan would suit men who are reluctant to be tested for prostate cancer due to the intrusive nature of the current examination technique – a rectal examination.
There are more than 49,000 prostate cancer cases per year and it is now the most commonly diagnosed cancer in the UK.
Following a successful trial in hundreds of men, experts have called Prostagram ‘a game-changer’ that will bring ‘vital’ mass screening for men ‘a step closer’.
Scientists at Imperial College London have developed a new fast scan, or Prostagram, for the early detection of prostate cancer potentially saving thousands of lives per year
‘Prostagram has the potential to form the basis of a fast, mobile national screening programme for prostate cancer and could be a game-changer,’ said senior study author Professor Hashim Ahmed, Chair of Urology at Imperial College London.
‘Prostagram also has the potential to detect more aggressive cancers earlier and pass over the many cancers which don’t need to be diagnosed.
‘By finding these aggressive cancers at the earliest opportunity, men have the opportunity to be offered less invasive treatments with fewer side effects.’
A ‘landmark’ trial of Prostagram, involving 408 men, has been detailed in a paper published in Jama Oncology.
The trial marks the first time that any scan has been accurate enough to be considered for use as a prostate cancer screening test.
The men, aged between 50 to 69 years, were invited for prostate cancer screening, using both the new scan and other established methods, from October 2018 to May 2019.
WHAT IS A PSA TEST?
There is no universal screening for prostate cancer, but many men opt for a prostate-specific antigen (PSA) blood test.
PSA is a protein produced by the prostate, and concentrations in the blood often increase if someone has prostate cancer.
But there are other reasons why PSA levels may be raised, such as a benign growth or an infection or inflammation. And in some people with cancer, levels are not raised at all.
If high PSA levels are detected, men can be referred for a biopsy, during which up to 20 samples of tissue are taken from the prostate to be examined.
But as biopsies sample only about one per cent of the gland, there is a 30 per cent chance that the cancer could be missed. Biopsies are also carried out with a needle, so carrying a small risk of infection afterwards.
Results showed that Prostagram picked up twice as many prostate cancers compared to the standard PSA (prostate specific antigen) blood test.
In total 4 per cent of volunteers had aggressive prostate cancer, of which around 75 per cent were identified by Prostagram and only 41 per cent by PSA.
Screening for prostate cancer using PSA testing can lead to problems of under-diagnosis and over-diagnosis, according to the team.
Over-diagnosis of unimportant cancers caused by PSA that are unlikely to harm those affected during their lifetime could provoke unnecessary medical interventions with unpleasant side-effects including urine leak or erectile dysfunction.
At present, some 12,000 men die each year from prostate cancer – compared to around 11,000 for breast cancer – and over the course of the last decade the number of deaths has overtaken that of breast cancer.
While breast cancer screening is routinely offered to women from 50 years, there is no equivalent screening programme for prostate cancer.
This is because PSA has also been shown routinely to miss aggressive life-threatening cancers.
About 15 per cent of men with aggressive prostate cancer can still have a normal PSA level, and, as a result, screening for prostate cancer using PSA blood tests is not recommended in any country.
The Imperial College London researchers have pointed out that their study sample was well represented by black men, who are at increased risk of prostate cancer.
The study enrolled 132 black men – making up 32.4 per cent of the total participants.
Graph shows the rise in UK breast cancer and prostate cancer deaths in recent years. Prostate cancer
One in four black men will get prostate cancer in their lifetime and one in eight men who are not black will develop prostate cancer – although why it is more common in black men is unknown.
Plans for an extensive trial covering 20,000 men are well advanced and will proceed in the coming months subject to funding.
If results from this study are similar or better than those revealed today, there is then a clear pathway to the widespread implementation of Prostagram into the general population.
Dr David Eldred-Evans from Imperial College London discussing the results of a prostagram with a trial participant
Creating a national screening programme for prostate cancer could make a major difference in reducing the number of men dying from this disease.
‘The encouraging results of this research study bring a mass screening programme for prostate cancer, equivalent to mammogram testing for women, a step closer,’ said Dr David Eldred-Evans, fellow researcher at Imperial College London and developer of the Prostagram.
‘A major achievement for the trial was the recruitment of ethnic minority and lower socio-economic participants broadly equivalent to their proportion within the community, which could be replicated in future general population screening trials.’
EXPLAINED: MAGNETIC RESONANCE IMAGING USED MAGNETIC FIELDS TO SEE INSIDE THE BODY
Magnetic resonance imaging (MRI) is a type of scan that uses strong magnetic fields and radio waves to produce detailed images of the inside of the body.
An MRI scanner is a large tube that contains powerful magnets. You lie inside the tube during the scan.
An MRI scan can be used to examine almost any part of the body, including the brain and spinal cord, bones and joints, breasts, heart and blood vessels and internal organs – such as the liver, womb or prostate gland.
Magnetic resonance imaging (MRI) is a type of scan that uses strong magnetic fields and radio waves to produce detailed images of the inside of the body. An MRI scanner is a large tube that contains powerful magnets. You lie inside the tube during the scan
The results of an MRI scan can be used to help diagnose conditions, plan treatments and assess how effective previous treatment has been.
Most of the human body is made up of water molecules, which consist of hydrogen and oxygen atoms. At the centre of each hydrogen atom is an even smaller particle, called a proton. Protons are like tiny magnets and are very sensitive to magnetic fields.
When you lie under the powerful scanner magnets, the protons in your body line up in the same direction, in the same way that a magnet can pull the needle of a compass.
Short bursts of radio waves are then sent to certain areas of the body, knocking the protons out of alignment. When the radio waves are turned off, the protons realign. This sends out radio signals, which are picked up by receivers.
These signals provide information about the exact location of the protons in the body. They also help to distinguish between the various types of tissue in the body, because the protons in different types of tissue realign at different speeds and produce distinct signals.
In the same way that millions of pixels on a computer screen can create complex pictures, the signals from the millions of protons in the body are combined to create a detailed image of the inside of the body.