Prostate cancer is a major killer
Routine prostate cancer screening could cut death rates from the disease by 20%, a major study suggests.
The results, which suggest 2,000 lives a year could be saved in the UK, have prompted a review of the current policy not to offer routine NHS screening.
The study, based on results from 162,000 men, assessed the impact of testing levels of a protein called prostate specific antigen (PSA).
It is published in the New England Journal of Medicine.
There has been concern that the PSA test could produce inaccurate results, leading to some men receiving unnecessary treatment which carries a risk of side effects such as impotence and incontinence.
But the latest study suggests that although the test can result in some men receiving treatment that they do not need, the benefits of screening may outweigh the risks.
PROSTATE SPECIFIC ANTIGEN
Prostate specific antigen (PSA) is a protein produced by cells of the prostate
It is present in small quantities healthy men, but is often elevated in the presence of prostate cancer
However, it cannot differentiate between aggressive cancers, which require urgent treatment, and slow growing cancers, which often require no treatment at all
PSA may also be elevated in men with other non-cancerous prostate disorders
In the UK men over 45 can ask their GP for a PSA test, but it is not offered as standard. Currently, only about 6% of men ask for the test.
Worldwide, prostate cancer is the second leading cause of cancer death.
The European Randomized Study of Screening for Prostate Cancer (ERSPC), which started in the early 1990s, involved men aged 55 to 69 from eight European countries.
Men whose PSA level was at least of 3.0 ng/ml (nanograms per millilitre) were offered further tests.
This led to an increase in early detection of cancer before it had a chance to spread to other parts of the body.
Overall, for every 1,408 men screened, one life was saved.
However, significant numbers of men were wrongly diagnosed with a problem requiring speedy action.
And a second US study, published in the same journal and based on 76,000 men, did not find a significant difference in death rate between men who had taken the PSA test, and those who were simply monitored.
Responding to the research, Ann Keen, health minister for England, said: "We will formally ask the UK National Screening Committee to review the evidence on prostate cancer screening and make recommendations.
"We look forward to examining this new evidence and are committed to having a prostate cancer screening programme if and when screening and treatment techniques are sufficiently well developed."
John Neate, chief executive of The Prostate Cancer Charity, welcomed the review of the current policy on screening.
He said: "This is the first significant study to provide evidence that a PSA-based screening programme could lead to a reduction in deaths from prostate cancer, in the UK."
However, Mr Neate stressed that the study had confirmed that a PSA test could not distinguish between aggressive and slow growing forms of prostate cancer.
Around 30% of cancers detected in the trial were slow growing, and did not require urgent treatment.
Mr Neate said: "We need to be mindful of the fact that prostate cancer is a complex disease and, unlike other common cancers, may not need immediate treatment."
"This new research highlights the critical importance of the development of a scientific test that can identify aggressive forms of prostate cancer and differentiate them from slow growing forms of the disease.
"Such a test would enable treatment to be focused on men for whom prostate cancer poses a serious risk to their health and avoid the over treatment of men with the harmless, slow growing forms of the disease."
Dr Chris Parker, from the Institute of Cancer Research, said the study did not necessarily mean routine screening should be adopted.
"Proponents of screening will point to the fact that it reduced the risk of death from prostate cancer by 20%.
"Critics will argue that this translates into a benefit for only one in 1,400 men, while around one in 30 men were harmed because they had to deal with the diagnosis and treatment of prostate cancer that would never otherwise have caused any problem."
Professor Julietta Patnick, head of NHS Cancer Screening Programmes, said: "This is exciting news and we look forward to hearing the views of the National Screening Committee in due course."