THE US: A widely used test for prostate cancer may not be as safe as once thought, according to a study published yesterday that sparked debate on whether the screening process should be overhauled.
The study found that 15 per cent of men with a "normal" reading on the PSA (prostate-specific antigen) blood test had a prostate tumour. In 2 per cent of the men, the cancer was life-threatening.
"There are many men walking around with high-grade prostate cancer who think they don't because they have a normal PSA," said Mr Ian Thompson of the University of Texas Health Science Centre in San Antonio, the leader of the study.
The team, writing in this week's edition of the New England Journal of Medicine, said the finding "underscores the need to consider fundamental changes in the approach to diagnosing prostate cancer". But in an editorial in the journal, Prof Ballentine Carter of the Johns Hopkins School of Medicine said there were good reasons for not changing the PSA standard.
Prof Carter said there was no evidence, at least not yet, that lowering the definition of "normal" would save lives or help men live longer. "The unexpected detection of cancer at lower PSA levels is more likely to identify disease for which treatment may not only be unnecessary, but also may fail to improve survival."
The PSA test measures a chemical called prostate-specific antigen in the blood.