Information about the stage of a tumor along with tumor grade and PSA level is central to choosing a treatment strategy. This information is often considered in predictive models, or nomograms, which calculate the probability of prostate cancer spread outside the prostate gland.
One such predictive model combines the clinical tumor (T) stage, the Gleason score from the tumor biopsy and the serum PSA to construct tables that allow an estimation of the likelihood of finding organ-confined, and thus, potentially curable disease with treatment of the prostate (surgery or radiation).
Predicting Treatment Outcome
In addition to predicting the likelihood of organ-confined disease, pretreatment models utilizing PSA, biopsy Gleason score, and clinical T stage also can be used to predict the chance of being cancer free following either surgery or radiation. In general, these models stratify patients into one of three defined prognostic groups:
- Low Risk Clinical stage T1c or T2a, serum PSA concentration <10
ng/mL, and biopsy Gleason score 6 or less. Men with low-risk disease have a
greater than 85 percent chance of being cancer free five years after
treatment with either surgery or radiation therapy.
- Intermediate Risk Clinical stage T2b, serum PSA 10 to 20 ng/mL, and
biopsy Gleason score of 7. Men with intermediate-risk disease have
approximately a 50 percent chance of being cancer free at 5 years after
- High Risk Clinical stage T2c disease, serum PSA >20 ng/mL, and a biopsy Gleason score of 8 or higher. High-risk patients have an approximately 33 percent chance of being cancer free five years after treatment.