Development and Validation of Preoperative Nomogram for Disease Recurrence Within 5 Years After Laparoscopic Radical Prostatectomy for Prostate Cancer

Abstract

To develop a nomogram that allows the prediction of disease recurrence using preoperative clinical factors for patients with clinically localized prostate cancer who are candidates for laparoscopic radical prostatectomy. Few published studies have combined the clinical prognostic factors into risk profiles that can be used to predict the likelihood of recurrence or metastatic progression after laparoscopic radical prostatectomy for prostate cancer. Using Cox proportional hazards regression analysis, we modeled the clinical data and disease follow-up data for 2272 men with clinically localized prostate cancer who had undergone laparoscopic radical prostatectomy. The clinical data included the pretreatment serum prostate-specific antigen level, biopsy Gleason grade, clinical stage, number of positive cores, and number of negative cores. Treatment failure was recorded when clinical evidence of disease recurrence was present, the serum prostate-specific antigen level had increased (2 measurements of ≥0.1 ng/mL and increasing), or the initiation of adjuvant therapy. Validation was also performed on an external data set of 1151 men. Treatment failure was noted in 229 of the 2272 men. The group without failure had a median follow-up of 16.7 months (range 0-120.6). The concordance index, when the nomogram was applied to the validation data set, was 0.77. The calibration in this data set was adequate. The predictions from this nomogram were more accurate than those using an open prostatectomy nomogram. We have externally validated a nomogram that predicts the 5-year probability of treatment failure among men with clinically localized prostate cancer treated with laparoscopic radical prostatectomy.