Researchers suggest that early prostate cancer testing on men in their late forties can predict nearly half of all prostate cancer deaths.

The study was carried out by researchers from Memorial Sloan-Kettering Cancer Center, New York, where they studied the medical records of 21,277 Swedish men aged 27 to 52 over a 30 year period.

They found that 10 percent of men who had the highest level of a protein known as prostate specific antigen (PSA), levels between the ages of 45 and 49 went on to account for 44 percent of all deaths from the disease.

The findings suggest that the use of this test, under which a doctor routinely test men for warning signs of prostate cancer by monitoring levels of PSA is still unreliable and conflicting because it does not directly detect cancer and can lead to patients receiving needless treatment.

Despite the uncertainties, the study shows that PSA screening programmes can "reduce the risk of over-diagnosis whilst still enabling early cancer detection for men at highest risk of death from prostate cancer", researchers reported in the British Medical Journal.

Whether PSA screening a good idea to can save lives is the important question, but further research is needed to provide the answer.