A suspicion of a diagnosis of prostate cancer is usually based on either induration or nodularity of the prostate on digital rectal examination or, more commonly, a rise in serum prostate specific antigen (PSA) level. The usual cut-off point for PSA is taken as 4 ng/ml, but in men below 65 a value of more than 2.5 ng/ml should raise suspicion. The Gleason grading of any cancer identified is an important part of the decision-making process concerning the need for active treatment, as opposed to surveillance alone. Gleason pattern 6 cancers are regarded as low risk, Gleason 7 intermediate risk and 8-10 high risk. [With external links to the current evidence base]