Aggressive prostate cancer refers to a form of prostate cancer in which the cancer grows or spreads more rapidly than in the majority of patients. Although most prostate cancers are highly curable, more aggressive cancers are likely to have a poor long-term prognosis, the Prostate Cancer Foundation explains.
The Gleason score is the most common method of determining the aggressiveness of prostate cancer. This score is the sum of two scores given by the pathologist who examines the cancer under a microscope. A score of 2 indicates a relatively low grade prostate cancer, while a score of 10 indicates an extremely aggressive case, the Prostate Cancer Foundation states.