Prognostic significance of tumor volume after radical prostatectomy: a multivariate analysis of pathological prognostic factors

Abstract

Objectives: To analyze the association between Gleason score, stage and status of surgical margins with tumor volume in prostate cancer progression after radical prostatectomy.

Methods: 200 consecutive radical prostatectomy specimens were analyzed. Preoperative clinical stage, PSA, results of prostate biopsies as well as pathological results were noted. A biochemical recurrence was defined as a single, postoperative detectable PSA level (>0.2 ng/ml). Tumor volume was compared to postoperative staging, Gleason score, and surgical margin status to predict tumor progression. Univariate and multivariate analysis using stepwise logistic regression were used to identify parameters with additional prognostic value.

Results: Pathological results of the prostatectomy specimens showed 149 (74.5%) pT2a-b, 29 (14.5%) pT3a and 22 (11%) pT3b tumors. Tumor volume was 0.57 cc for pT2a, 1.2cc for pT2b, 1.7cc for pT3a and 2.9cc for pT3b, respectively (p<0.05). Taken together, mean volume for pT2 and pT3 were 1.06 and 2.2 cc, respectively (p<0.0001). Five-year progression-free actuarial survival was 69.7%. Using univariate analysis, tumor progression correlated with final Gleason score (p<0.0007), positive surgical margins (p=0.02), tumor volume (p=0.009) and stage (p<0.0001). In a multivariate analysis, tumor progression correlated only with the final Gleason score (p=0.04) and stage (p=0.0002).

Conclusion: Gleason score and pathological stage are independent factors to predict prostate cancer progression after radical prostatectomy. When these parameters are known, tumor volume does not provide additional information.