Using the percentage of biopsy cores positive for cancer, pretreatment PSA, and highest biopsy Gleason sum to predict pathologic stage after radical prostatectomy: the Center for Prostate Disease Research nomograms.

OBJECTIVES: To develop probability nomograms to predict pathologic outcome at the time of radical prostatectomy (RP) on the basis of established prognostic factors and prostate biopsy quantitative histology. METHODS: Using information from the database of the Center for Prostate Disease Research (CPDR), univariate and multivariate analyses were performed on 1510 men who had undergone transrectal ultrasound and biopsy for diagnosis and had radical prostatectomy as primary therapy, with variables of age, race, clinical stage, pretreatment prostate-specific antigen (PSA), biopsy Gleason sum, and percentage of biopsy cores positive for cancer (total number of cores positive for cancer divided by the total number of cores obtained). The percentages of biopsy cores positive were grouped as less than 30%, 30% to 59%, and greater than or equal to 60%. The three most significant variables were used to develop probability nomograms for pathologic stage. RESULTS: PSA, biopsy Gleason sum, and percentage of cores positive were the three most significant independent predictors of pathologic stage. The assigned percentage of biopsy core-positive subgroups along with pretreatment PSA and highest Gleason sum were used to develop probability nomograms for pathologic stage. CONCLUSIONS: Pretreatment PSA, highest biopsy Gleason sum, and the percentage of cores positive for cancer are the most significant predictors for pathologic stage after radical prostatectomy. On the basis of these findings, CPDR probability nomograms were developed to predict pathologic outcome at the time of RP.

Increasing the number of core samples taken at prostate needle biopsy enhances the detection of clinically significant prostate cancer.

OBJECTIVES: The number of cores obtained during transrectal ultrasound-guided prostate biopsy to detect cancer has increased from the previous standard of 6. Increasing the number of biopsy cores taken results in a higher prostate cancer detection rate. Because criteria for defining the clinical significance of localized prostate cancer has been proposed, the question may be asked whether the increased number of tumors found is clinically significant. METHODS: The Urology Service's surgical log database revealed 369 patients who underwent radical prostatectomy as primary therapy between January 1997 and March 2001. Only men who had had more than six core biopsies that included the standard sextant and lateral horns of the peripheral zone biopsies were considered. The hospital's clinical information system was then used to extract all additional data for age, clinical stage, pretreatment prostate-specific antigen level, and transrectal ultrasound-guided biopsy and subsequent whole mount pathology results, including pathologic stage, number of tumors, largest single and aggregate tumor volumes, highest tumor Gleason score, and tumor locations. A total of 127 men comprised our final group. RESULTS: Subgrouping based on the location of positive biopsy results yielded 40 (31.5%) in the standard sextant biopsy only, 31 (24.4%) in the lateral horns of the peripheral zone only, and 56 (44.1%) of 127 tumors in both zones. The Gleason score was similar throughout. The margin-positive rate was 12.5% for the sextant-only positive biopsies, 12.9% for the lateral horn-only positive biopsies, and 42.9% for the both positive biopsies. The insignificant tumor rate for the group as a whole was 5.5% (7 of 127). The insignificant tumor rate for the lateral horn-only positive biopsies was 3.2% (1 of 31). CONCLUSIONS: The addition of laterally directed biopsies increases the rate of prostate cancer detection, and the vast majority of these tumors are clinically significant.