A new nomogram to predict pathologic outcome following radical prostatectomy

Abstract

Objective: To develop a preoperative nomogram to predict pathologic outcome in patients submitted to radical prostatectomy for clinical localized prostate cancer. Materials and Methods: Nine hundred and sixty patients with clinical stage T1 and T2 prostate cancer were evaluated following radical prostatectomy, and 898 were included in the study. Following a multivariate analysis, nomograms were developed incorporating serum PSA, biopsy Gleason score, and percentage of positive biopsy cores in order to predict the risks of extraprostatic tumor extension, and seminal vesicle involvement. Results: In univariate analysis there was a significant association between percentage of positive biopsy cores (p < 0.001), serum PSA (p = 0.001) and biopsy Gleason score (p < 0.001) with extraprostatic tumor extension. A similar pathologic outcome was seen among tumors with Gleason score 7, and Gleason score 8 to 10. In multivariate analysis, the 3 preoperative variables showed independent significance to predict tumor extension. This allowed the development of nomogram-1 (using Gleason scores in 3 categories -2 to 6, 7 and 8 to 10) and nomogram-2 (using Gleason scores in 2 categories -2 to 6 and 7 to 10) to predict disease extension based on these 3 parameters. In the validation analysis, 87% and 91.1% of the time the nomograms-1 and 2, correctly predicted the probability of a pathological stage to within 10% respectively. Conclusion: Incorporating percent of positive biopsy cores to a nomogram that includes preoperative serum PSA and biopsy Gleason score, can accurately predict the presence of extraprostatic disease extension in patients with clinical localized prostate cancer.

External validation of a brazilian predictive nomogram for pathologic outcomes following radical prostatectomy in tertiary teaching institutions: the USP nomograms

“…It has been suggested that proper calibration of a nomogram is more clinically useful than is its (6,21). This study confirmed these findings.…”

“…This study was based on the premise that the current sample would differ in significant aspects from that of Crippa and colleagues' original study (6). To test this hypothesis, demographic data, including the clinical stage, PSA values, and pathological findings presented in Table-1 of the original study were compared to data from the sample of the current study by two-sided unpaired t-tests and z--tests for proportions, as appropriate.…”

“…For external validation, the probability of OCD was estimated for each patient in the validating sample as the average probability predicted by nomograms 1 and 2 of the original study (6), based on the respective ranges of PSA levels (0-4, 4.1-10, 10.1-20, and above 20ng.mL −1 ), of Gleason scores (2-6, 7 and 8-10 in nomogram 1, and 2-6 and 7-10 in nomogram 2) and PPBC (0-25%, 25.1-50%, 50.1-75% and 75.1-100%). Receiver operating characteristic (ROC) curves and the respective areas under the curves (AUC) accessed the discriminatory capability of the nomograms.…”

“…In 2006, Crippa et al (6) published the first population-based study in Brazil aimed to predict organ-confined disease (OCD). PSA levels, Gleason score from prostate biopsies and percentages of positive biopsy cores (PPBC) were used as predictor variables.…”

Sobrevida e fatores prognósticos de pacientes com câncer de próstata clinicamente localizado

“…In these models, discordant prognostic variables are incorporated in the estimate of the patient's individual risk. 5,7,12,21 Biochemical recurrence and staging (after surgery) are commonly used outcomes in studies of clinical prognostic factors in prostate cancer. Major outcomes such as metastases and specific mortality are not widely used as they require long follow-up.…”