SCREENING men for prostate cancer could reduce deaths from the disease by a fifth despite doubts about the diagnostic test used, a study has found.

The positive effect of screening increases over time, the research involving more than 162,000 men showed.

Over a period of nine years, screening reduced the number of men dying from prostate cancer by 15 per cent, increasing to 22 per cent after 11 years.

During the whole 13-year follow-up period, the risk of death was 21 per cent lower in men who were screened than in those who were not.

Screening for prostate cancer is controversial because the initial diagnostic test patients have, to measure blood levels of the biomarker prostate specific antigen (PSA), is so unreliable.

Higher than normal PSA readings can be obtained from healthy men, and low readings from individuals with cancer. For this reason, routine screening for prostate cancer is not carried out in the UK.

The European Rand-omised study of Screening for Prostate Cancer (ERSPC) recruited men aged 50 to 74 from eight European countries, none of which were in the UK. Even though the findings demonstrated that screening reduced deaths, the authors said it was still too soon to introduce population-wide screening.

Lead researcher Professor Fritz Schroder, from Erasmus University Medical Centre in the Netherlands, said further research was needed to reduce "over-diagnosis" of prostate cancer cases. The research was published in medical journal The Lancet.