Early prostate-specific antigen relapse after radical retropubic prostatectomy: Prediction on the basis of preoperative and postoperative tumor characteristics

Objectives: This study was undertaken to distinguish between patients who w ill and will not benefit from a retropubic radical prostatectomy (RRP) for clinically localized prostatic carcinoma (PCa) on the basis of preoperative and postoperative tumor characteristics. Methods: Data of 318 consecutive patients who underwent RRP for clinically localized PCa were reviewed. Preo perative characteristics used included clinical stage, findings on transrec tal ultrasonography, prostate-specific antigen (PSA) values, Gleason grade, number of positive biopsies, number of biopsies containing any Gleason gra de! 4 and/or 5 cancer, and number of biopsies with predominant (>50% of can cerous tissue) Gleason grade 4 and/or 5 cancer. Postoperative characteristi cs included patho-logic stage, Gleason grade, margin status, cancer volume, and volume of Gleason grade 4 and/or 5 cancer. The impact on biochemical r elapse after RRP were calculated by Cox regression and CART (classification and regression tree) analysis to establish low, intermediate, and high ris k of recurrence. Results: Of patients who underwent RRP, 66% showed no evid ence of relapse after a follow-up of 42 months. All preoperative and postop erative characteristics showed a significant association with biochemical r elapse. Cox regression of preoperative characteristics showed the number of positive biopsies with predominant Gleason grade 4 and/or 5 cancer to be t he most accurate predictor of failure (p < 0.0001), followed by the number of positive biopsies and PSA. CART analysis distinguished between four risk groups on the basis of the same characteristics as in the Cox regression. The low-risk group consisted of 232 patients (75.1%) and the high-risk grou p of 17 patients (5.5%); corresponding Kaplan-Meier curves showed a 2-year PSA-free survival rate of 97% for the low-risk group and 20% for the high-r isk group. Cox regression of postoperative characteristics recognized the v olume of Gleason grade 4 and/or 5 as the characteristic with the strongest association with biochemical failure. CART analysis distinguished between f our risk groups, using the volume of high-grade cancer as the most influent ial characteristic. The corresponding Kaplan-Meier curves showed for the lo w-risk group (n = 79; 29.6%) a PSA-free survival rate of 96% after 42 month s and for the high-risk group (n = 47; 17.6%) a 21% PSA-free survival rate after 42 months. Conclusion: For preoperative and postoperative estimation of biochemical recurrence after RRP, a quantitative analysis of high-grade cancer, expressed by the number of preoperative biopsy cores containing hig h-grade cancer and the volume of cancer, proved to be the best predictor of relapse. CART analysis might be useful in advising patients for their best therapy options. However, defined characteristics of risk groups should be evaluated with new prospective data before they are used routinely.