Peter Moore: Fight against prostate cancer requires measured approach

It is understandable.

With over 52,000 new cases and about 12,000 deaths, shouldn’t the NHS roll out a screening programme for prostate cancer? After all, it affects one in eight of all men during their lifetime and has increased by 25 per cent in the last five years, overtaking breast cancer as the UK’s commonest cancer.

Most importantly, the outlook is far better if diagnosed early. So why not screen all men over fifty for this terrible disease? This is the argument of Sir Chris Hoy, the Olympic cycling champion who has terminal prostate cancer at the age of 48.

There is a blood test, the PSA, which can diagnose prostate cancer, but on its own it is not reliable enough for a national screening programme. The test can be normal when someone has early prostate cancer, and sometimes it is positive when there is no cancer.

A large study back in the 1990s found that men who were screened using the PSA blood test had a worse outlook than men who waited for symptoms. This was a long time ago, and things have moved on both in screening and treatment.

The problem we have is that if the PSA suggests cancer, until recently the only further test available was a biopsy. This is not only unpleasant but also carries a small risk. In a white man with no family history of the disease, the very small risk of the biopsy outweighs any benefit.

Black men and people with a strong family history are more likely to develop the cancer. Does the small biopsy risk in these men still outweigh the risk of prostate cancer?

Just to make the statistics even more confusing, black men do not have an increased risk of the advanced cancer even though they have a higher risk of developing the disease. It is possible that their prostate cancer is less aggressive than in white men.

Men of Asian heritage have a low risk of the disease. Should the blood test be reserved for high-risk men? Chris Hoy’s father and grandfather both had prostate cancer, and so he was at high risk.

The British Journal of General Practice recently published a paper signed by fifteen prostate cancer experts arguing that men over forty-five at high risk should be offered a PSA. If it is raised, they could then be offered an MRI, which has a much lower risk than a biopsy.

Other tests are being developed. A company in Cambridge has developed a screening test using AI. Men give a blood and urine test which analyses DNA to check for genes known to increase the risk of prostate cancer as well as over one hundred other biological markers for the cancer. This looks hopeful, but it is early days.

To try to clarify the situation, there is now the “Transform trial” underway, a £42 million research programme to find the best way to screen for prostate cancer. If successful, screening could reduce deaths from this disease by 40 per cent.

Before any screening test is introduced in the NHS, it is assessed by the National Screening Committee, who look objectively at all the evidence. The minister, Wes Streeting, has asked this committee to look again at the evidence in view of all the latest research.

Although the headlines screamed “Wes Streeting backs national prostate cancer screening”, and the charity Prostate Cancer UK said, “It’s great to hear Wes Streeting express his support for a prostate cancer screening programme,” his actual statement was more nuanced.

He did say he’d like to see a national screening programme but that “decisions in this area need to be evidence based.” The minister is not going to jump on a bandwagon to gain popularity but quite rightly will listen to experts of the National Screening Committee.

Over the next few years, an evidence-based screening programme for prostate cancer will probably be developed. With 12,000 deaths a year, there is understandable pressure to “do something”, but it is vital that the “something” really does save lives.

We must wait for all the evidence, but things are looking hopeful.