PREDICTION OF CAPSULAR PERFORATION AND SEMINAL-VESICLE INVASION IN PROSTATE-CANCER

Purpose: Capsular perforation and seminal vesicle invasion are unfavor able prognostic factors in prostate cancer. Accurate preoperative pred iction of these factors would be clinically useful for planning treatm ent, especially in patients being considered for radiation therapy, ne rve sparing radical prostatectomy and watchful waiting. However, curre nt methods are imprecise at predicting the presence and extent of thes e factors. We determined which combination of commonly available preop erative variables provides the best prediction of capsular perforation and seminal vesicle invasion in patients with clinically localized pr ostate cancer. Materials and Methods: We reviewed the preoperative med ical records and biopsy findings from 314 patients with clinical stage s T1cNOMO to T2cNOMO cancer who underwent radical retropubic prostatec tomy and bilateral pelvic lymphadenectomy between September 1991 and J une 1993. Radical prostatectomy specimens were embedded and evaluated by whole mount sections. Results: Capsular perforation was observed in 104 patients (33.1%) and seminal vesicle invasion was noted in 46 (14 .6%). Preoperative variables predictive of capsular perforation and se minal vesicle invasion on univariate analysis were serum prostate spec ific antigen (PSA) concentration, clinical stage, Gleason primary and secondary patterns, Gleason score, nuclear grade, perineural invasion and percent cancer in the biopsy specimens. On multivariate analysis i ndependent prognostic factors for capsular perforation and seminal ves icle invasion were PSA, Gleason score and percent cancer in the biopsy specimens. Conclusions: The combination of serum PSA concentration, G leason score and percent cancer in the biopsy specimens provides the b est prediction of capsular perforation and seminal vesicle invasion, M odels based on this combination of factors may be clinically useful to stratify patients for nonoperative treatment.