Under staging and under grading in a contemporary series of patients undergoing radical prostatectomy: results from the Cancer of the Prostate Strategic Urologic Research Endeavor database.

ABSTRACT

PURPOSE: We determined the prevalence of under staging and under grading in contemporary patients undergoing radical prostatectomy in academic and community based urology practices, and defined important predictors of under staging in this population. MATERIALS AND METHODS: We compared clinical T stage and biopsy Gleason score with pathological T stage and prostatectomy Gleason score in 1,313 patients enrolled in the Cancer of the Prostate Strategic Urologic Research Endeavor database, a longitudinal registry of patients with prostate cancer, who underwent radical prostatectomy, including 53% since 1995. Under grading was determined for the primary and secondary Gleason patterns and defined as a biopsy Gleason pattern of 1 to 3 that became pathological Gleason pattern 4 or 5. Under staging was defined as a clinically organ confined tumor that was extraprostatic stages pT3 to 4 or N+ at radical prostatectomy. Univariate and multivariate analysis was performed to determine important risk factors for under staging and significant risk factors were used to identify the likelihood of under staging in clinically relevant patient subgroups. The importance of the percent of positive biopsies in regard to the likelihood of under staging was determined by assigning patients to previously described risk groups based on serum prostate specific antigen (PSA) at diagnosis and biopsy Gleason score. RESULTS: Under grading of primary and secondary Gleason patterns occurred in 13% and 29% of patients, respectively, while under staging occurred in 24%. Univariate and multivariate analysis revealed that PSA at diagnosis, biopsy Gleason score and the percent of positive biopsies were significant predictors of under staging. The percent of positive biopsies appeared to be most important for predicting the likelihood of extraprostatic disease extension in intermediate or high risk disease based on serum PSA at diagnosis and biopsy Gleason grade. CONCLUSIONS: The prevalence of under grading and under staging in contemporary patients undergoing radical prostatectomy may be lower than previously reported. PSA at diagnosis, biopsy Gleason score and the percent of positive biopsies are important predictors of under staging. The percent of positive biopsies should be incorporated into risk assessment models of newly diagnosed prostate cancer.