Interpreting the numbers when a PSA test comes back can almost be an art. Things such as a man's age, comorbidities, previou test results all have to come into play when making the decision to have a prostate biopsy.

An article in the New York Times, Deciphering the Results of a Prostate Test does a good job of attempting to explain what doctors consider when evaluating this screening tool's results.

Check it out, it is very informative reading.