Percentage of Gleason pattern 4 and 5 predicts survival after radical prostatectomy.

Background: Morphologic and clinical heterogeneity within tumor grades is well recognized in prostate cancer. The objective of the current study was to determine whether the combined percentage of Gleason patterns 4 and 5 in radical prostatectomy specimens is an independent predictor of cancer-specific survival in prostate cancer patients.
Methods: The radical prostatectomy specimens were analyzed from 504 consecutive prostate cancer patients who were treated at Indiana University Medical Center between 1990 and 1998. Various clinical and pathologic characteristics were analyzed.
Results: A higher combined percentage of Gleason patterns 4 and 5 was associated with older age, higher preoperative serum prostate-specific antigen level, higher pathologic stage, positive surgical margins, extraprostatic extension of tumor, higher Gleason score, perineural invasion, and lymph node metastasis. In the multivariate Cox regression model, the combined percentage of Gleason patterns 4 and 5 was found to be an independent predictor of cancer-specific survival (P = .04).
Conclusions: The combined percentage of Gleason patterns 4 and 5 is a powerful predictor of prostate cancer-specific survival. Assessment of high-grade cancer amounts may allow for better stratification of patients into appropriate prognostic groups and treatment protocols.