Background: Few published studies have combined clinical prognostic factors into risk profiles that can be used to predict the likelihood of recurrence or metastatic progression in patients following treatment of prostate cancer. We developed a nomogram that allows prediction of disease recurrence through use of preoperative clinical factors for patients with clinically localized prostate cancer who are candidates for treatment with a radical prostatectomy.
Methods: By use of Cox proportional hazards regression analysis, we modeled the clinical data and disease follow-up for 983 men with clinically localized prostate cancer whom we intended to treat with a radical prostatectomy. Clinical data included pretreatment serum prostate-specific antigen levels, biopsy Gleason scores, and clinical stage. Treatment failure was recorded when there was clinical evidence of disease recurrence, a rising serum prostate-specific antigen level (two measurements of 0.4 ng/mL or greater and rising), or initiation of adjuvant therapy. Validation was performed on a separate sample of 168 men, also from our institution.
Results: Treatment failure (i.e., cancer recurrence) was noted in 196 of the 983 men, and the patients without failure had a median follow-up of 30 months (range, 1-146 months). The 5-year probability of freedom from failure for the cohort was 73% (95% confidence interval = 69%-76%). The predictions from the nomogram appeared accurate and discriminating, with a validation sample area under the receiver operating characteristic curve (i.e., comparison of the predicted probability with the actual outcome) of 0.79.
Conclusions: A nomogram has been developed that can be used to predict the 5-year probability of treatment failure among men with clinically localized prostate cancer treated with radical prostatectomy.