New studies from JAMA suggest that the rate of PSA rise is key to predicting prostate cancer:

Instead of simply testing once for PSA and deciding that it is "high" or "normal," D'Amico says it appears to be more useful to test at regular intervals. This gives a reading on PSA change -- what doctors call PSA velocity.

"Our study shows that men who experience a two-point rise in PSA in the year preceding a diagnosis of prostate cancer -- despite a low level of PSA and despite a biopsy showing a supposedly 'favorable' prostate cancer -- have more aggressive cancer and need more aggressive treatment to cure it."

Men whose PSA levels rose more than two points in a year had a 12-fold higher risk of dying from prostate cancer than men whose PSA levels rose less quickly.

There is currently controversy about the best way to use the PSA. Current recommendations suggest discussing prostate cancer screening (both with a PSA and digital rectal exam) with your physician by age 50. (DeNoon, "Prostate Cancer: PSA Change May Be Key to Risk", WebMD, Jul.26)