Much as I admire and respect Sir Chris Hoy for drawing attention to prostate cancer, I fear he is quite wrong to call for younger men to undergo PSA tests to screen them for the disease, as he did yesterday.
I also think that the health secretary, Wes Streeting, responded in a shamefully opportunistic way to Sir Chris’s call, saying that he’s asked the NHS to look at the case for lowering the screening age ‘as a result of [Sir Chris’s] intervention’, offering false hope.
Currently men aged 50 or over can ask their GP for a PSA test, but Mr Streeting will know that this is not a reliable test – in fact PSA testing has previously been rejected as a screening tool in the UK because it leads to many men being wrongly diagnosed and treated for the disease – and studies show mixed results on whether screening lowers the death rate from prostate cancer.
Furthermore, as Mr Streeting should know, a major trial called Transform is already now looking for the best way to screen men, using the most promising new tests (such as fast MRI scans and genetic testing).
Much as I admire and respect Sir Chris Hoy (pictured with wife Sarra Kemp) for drawing attention to prostate cancer, I fear he is quite wrong to call for younger men to undergo PSA tests to screen them for the disease, writes DR MARTIN SCURR
The problem with a blood test for PSA is that levels can rise for a number of quite benign reasons, not just prostate cancer.
PSA – or prostate specific antigen – is a protein produced by the prostate gland and levels can be raised after riding a bicycle, for instance.
PSA can also be raised for a day – or three – after sex, and in patients with a loaded rectum caused by chronic constipation.
And the worry is what can happen too often in these circumstances, something we in medicine call ‘false positive’ results: high levels of PSA that lead to (needless and potentially risky) investigations for prostate cancer and (needless and great) anxiety, when there is no cancer.
These investigations include a biopsy – where a needle is inserted via the perineum, the area between the scrotum and anus, and into the prostate to take tissue samples.
This should be done using an MRI scan to guide it, but in some places ultrasound is used, which is less precise in what it shows.
Sir Chris is one of Britain’s most decorated Olympians, winning six gold medals
Perhaps not surprisingly, given the area where it’s taken, the biopsy process carries a low but very real risk of infection (affecting between 2 and 6 per cent of men biopsied, depending on the study) – and any infection inevitably carries the risk of sepsis (with prostate biopsies this can vary from 0.3 per cent to 3 per cent).
And as many as 75 per cent of men with high PSA undergo this process and are found not to have cancer – this high false positive rate is why PSA is regarded as unreliable.
As well as submitting healthy men to tests they don’t need because of false positive results, the PSA test can also be inaccurate, producing ‘false negative’ results – where a man is told, wrongly, that he doesn’t have prostate cancer.
The reason we still use this unreliable test is that it’s been all we had (and even then, it wasn’t actually developed as a diagnostic test, but to monitor a prostate cancer patient’s response to treatment, and check for recurrence).
The other factor we must consider is the NHS’s ability at this point to deal with a screening programme – for example, at Chelsea and Westminster Hospital I understand the current workload is approximately 20 biopsies each week.
There just isn’t the capability in the NHS, in terms of staff and machinery, to deal with the huge workload that faulty PSA test results from so many men would lead to.
The priority must be to screen patients at higher risk of prostate cancer, such as men from certain Black and ethnic minority groups, and those with a first-degree relative who had prostate cancer at an age below 60.
Sir Chris was at high risk as both his father and grandfather had the disease, which would have justified checking him from the age of 40.
But in my view not every man needs to be screened at that age unless he has such a family history. We must take the time and trouble to discriminate.
So while Sir Chris has my very best wishes and hopes, I must politely dissent on his view that the PSA test should be used to screen younger men: it would be a real mistake.