A BLOOD test for prostate cancer may have significantly improved the survival prospects of patients diagnosed with advanced disease, research has shown.

Scientists identified a reduced risk of dying of almost one-third since the widespread introduction of the PSA (prostate specific antigen) test in the late 1980s and early 1990s.

The PSA test identifies a protein in the blood that can signify the presence of prostate cancer.

Critics say the test is too unreliable to be used for routine screening, which is why there is no automatic PSA testing in the UK. But the new American study suggests widespread PSA testing can save lives.

The test is used more often in the US, although the American Cancer Society no longer recommends it for routine screening.

Scientists studied survival data from trials conducted before and after PSA testing was introduced in 1987.

Study leader Professor Ian Thompson, from the University of Texas at San Antonio, said: "While not all of these welcome improvements can be attributed strictly to PSA testing, without a doubt it has played a role in extending many lives."