Gleason Grading, Biochemical Failure, and Prostate Cancer–Specific Death

Abstract Objectives: To examine the relationship between the recently defined Gleason grade groups and prostate cancer–specific mortality. Methods: If the probability of prostate cancer–specific death is symbolized as P(PSD), the probability of biochemical failure is symbolized as P(BF), and the probability of prostate cancer–specific death after biochemical failure is symbolized as P(PSD | BF), then the rules of probability provide a way to estimate P(PSD) as P(PSD) = P(PSD | BF) * P(BF) Using this model and data from the literature for P(PSD | BF) and P(BF), I estimate here values of P(PSD) for the five newly described Gleason grade groups. Results: The expected probability of prostate cancer– specific death is closely related to the new Gleason grade groups and ranges from a low of 0.014 for grade group 1 to a high of 0.15 for grade group 5. Conclusions: Although using the original study patient population may require years of additional follow-up to examine prostate cancer–specific mortality, the evidence available now indicates that these new Gleason grade groups relate to prostate cancer–specific mortality.