Cochrane reviewers conclude PSA testing reduces deaths from prostate cancer

An updated Cochrane review has concluded there is evidence that PSA screening reduces prostate cancer deaths.

The analysis of 800,000 men aged 50 to 74 years who took part in large trials across Europe and the US found that PSA testing reduces prostate cancer deaths by around two per 1,000 men screened.

Screening detected around 30% more prostate cancers overall, mostly at an earlier stage, the authors reported.

Roughly 36 additional cancers were diagnosed per thousand men screened, for every one to two deaths prevented.

The update, which looked at 23 years of follow up, offers a different conclusion to the previous Cochrane review on the topic in 2013 which did not find sufficient evidence that PSA screening reduced prostate cancer deaths.

But some of these may never have caused symptoms or harm during a man’s lifetime, the researchers said.

The studies included in the review did not systematically assess impacts on quality of life, such as complications from biopsies, sexual dysfunction and urinary problems, and policy makers making screening decisions will need to take harms into account, they added.

It does not necessarily change the debate in the UK on whether population screening for prostate cancer should be introduced or whether some high-risk groups should be targeted for PSA testing because the National Screening Committee had already looked at the research involved in the Cochrane review.

In November last year, the NSC advised against routine NHS prostate cancer screening after reviewing a range of options – but said there is evidence screening should be considered for men with faulty BRCA genes.

It put the recommendation out for consultation and a final decision has yet to be announced.

The committee had come under increased pressure in recent months to reconsider PSA testing policy, particularly after Sir Chris Hoy’s announcement that he had been diagnosed with terminal cancer. 

A £42m trial – TRANSFORM – has been set up in the UK to test combinations of the most promising screening techniques available, including PSA blood tests, genetic tests and fast MRI scans.

Review author Dr Philipp Daim, from the University of Minnesota, said: ‘With new data now available, we can now say with moderate certainty that PSA screening reduces prostate cancer deaths in men with a sufficient life expectancy.

‘This suggests that for the right patient – someone who is well-informed, has a good life expectancy, and understands the full implications of screening – there is now a reasonable evidence base to support a conversation about PSA screening.

‘This represents an important change in the evidence for future guideline developers and policy makers to consider.’

Co-author Dr Juan Franco, from Heinrich Heine University Düsseldorf, added: ‘We want to be clear that this is not a blanket endorsement of universal screening.

‘The decision should always be made between a patient and their doctor, with a full understanding of both the potential benefits and the very real risks of overdiagnosis and unnecessary treatment.’

Dr Adam Brentnall, reader in biostatistics at Queen Mary, University of London, explained it was a complex picture and there were limits to what pooled data from trials with different approaches could show. He also noted the importance of ongoing studies that could provide answers about more modern approaches to screening.

‘Long-term data from high-quality randomised trials provides key evidence to determine suitability of screening.

‘However, it’s not sufficient on its own to decide whether an organised national screening programme should be introduced. We also need to weigh broader benefits, harms, and costs.’

Dr Matthew Hobbs, director of research at Prostate Cancer UK, said the study provided a robust review of the current clinical trial evidence on PSA screening.

‘We know from past trials that screening based on PSA can save men’s lives, but not nearly enough. 

‘More research is needed to plug critical evidence gaps and to find the safest and most effective way to screen men for prostate cancer, ensuring the benefits outweigh the harms.’