US urologists have devised a way of predicting the risk of a recurrence of prostate cancer after a radical prostatectomy. Using a study sample of 1,997 men who had had a radical prostatectomy for localised prostate cancer, the urologists studied the time it took for the concentration of prostate-specific antigen to increase after surgery and whether metastatic disease developed during the study period.

This antigen usually increases in cases of prostate cancer but should be undetectable after a prostatectomy. The researchers' formula predicts metastatic risk. Patients at high risk had had high-grade tumours and an antigen concentration that rose above zero within two years of surgery.