'Unanswered questions' over PSA prostate screening despite 11-year follow-up of trial
A large 11 year long European study has failed to establish whether the benefits of prostate cancer screening outweigh the risks, despite showing that it can reduce death rates from the disease.
The European Randomised Study of Screening for Prostate Cancer (ERSPC) was set up in 1991 to assess the impact of routine screening with the prostate-specific antigen (PSA) blood test.
The latest findings from the study have been published in The New England Journal of Medicine after 11 years of follow-up.
The study involved 182,000 European men aged 50-74, who were divided into two groups. One group was offered PSA screening on average once every 4 years, while the other group did not receive screening.
Death rates from prostate cancer were 21 per cent lower among participants who were given PSA screening.
However, this reduction was only achieved after a considerable use of resources, and the new findings show that there has been little change in the apparent benefit of PSA screening since the previous results were published in 2009.
In order to prevent one death from prostate cancer during the 11-year period, researchers said 1,055 men would need to be invited for screening, resulting in 37 cancers being detected.
The research was initially carried out in the Netherlands and Belgium, with Sweden, Finland, Italy, Spain and Switzerland joining the study between 1994 and 1998.
Under current UK guidelines, men are advised to discuss PSA testing with their GP, who will explain the risks and benefits. Men with a high PSA and an enlarged prostate are usually offered a biopsy, which is not always conclusive.
On top of this, doctors currently don’t have a way to accurately predict whether a tumour is likely to be aggressive and need urgent treatment, or merely require monitoring.
Commenting on the ERSPC findings, Yinka Ebo, health information officer at Cancer Research UK, said the new results “leave just as many questions unanswered”.
“For example, it is still not clear whether the overall benefits of prostate screening would outweigh the possible harms, such as impotence and incontinence, nor how best to ensure men don’t receive unnecessary tests and treatments,” she said.
"What this study does show is that we desperately need a better tool than PSA alone for detecting prostate cancers, and a way of differentiating between aggressive cancers that need treating and ones that do not - a challenge that Cancer Research UK scientists are tackling.
"In the meantime, it’s important that men talk to their GPs if they are concerned about the disease, so that they’re fully informed of the risks and benefits of the PSA test,” she added.