Screening tests don't detect prostate cancer

New evidence suggests that men with early signs of prostate cancer are being missed because screening techniques are inadequate.

Researchers used blood from 658 men, banked in 1980, to test whether levels of prostate specific antigen (PSA), a biochemical marker linked with prostate cancer, could predict the development of cancer later in life.

The higher the level of PSA, the higher the risk of developing cancer. Men with PSA levels in the range of 3-10 ng/mL had a 29 per cent probability of developing prostate cancer within 15 years.

It was also found that PSA screening followed by a biopsy detected only 40 per cent of the cancers that eventually developed.

Why so many potential cancer cases are missed is not clear. It may be due to the practice of doing single, rather than regular, PSA testing. However, it may also be that physicians interpret test results differently. It does seem, however, that men with higher levels of PSA may require more careful monitoring than those with PSA levels of 3 ng/mL or lower (Br J Urol Int, 2000; 85: 1078-84).