New way to predict prostate cancer severity: size of prostate.

It is still difficult to gauge the probability that a patient with low-risk prostate cancer may be upgraded to a higher prostate cancer stage. Upgrading, using the Gleason score after a biopsy, can occur in anywhere from 30% to 50% of prostate cancer cases. Low-risk disease is generally associated with low prostate-specific antigen (PSA) production and a Gleason score of 6 or lower. The Gleason score is a measure of the severity of the prostate cancer assessed using specimens from the initial biopsy.