Diagnosis, prognosis and management of incidentally found prostate cancer.

Incidentally discovered cancer of the prostate may be divided into focal and diffuse disease. The focal tumour tends to be of low grade and low-volume and in the majority of patients runs a clinically benign course. In 10-15% of untreated patients, however, progression occurs by 10 years after diagnosis. At the same stage of follow-up 30-63% of the patients have died of other causes, with no evidence of recurrence. In patients with low-grade focal cancer of the prostate, radical prostatectomy may be curative. An alternative management option is to closely observe these patients. Digital rectal examination, prostatic specific antigen, transrectal prostatic ultrasound and repeated prostatic biopsies can all make contributions to the follow-up of these patients.