Biochemical outcome of small volume or insignificant prostate cancer treated with radical prostatectomy.

Abstract

279 Background: We examined biochemical outcome of small volume prostate cancers (<0.5 cc, SVCa), and insignificant prostate cancers (<0.5 cc and Gleason scores <7, InsigCa) treated with radical prostatectomy. Methods: Between April 2000 and May 2011, 609 patients with prostate cancer were treated with radical prostatectomy in Hirosaki University Graduate School of Medicine. Of these, 237 were excluded from analysis because of pre-operative adjuvant treatment. The remaining 372 patients were eligible in the present study. Along with the routine pathological assessment, tumor volume (TV) was assessed in all patients. Biochemical recurrence (BCR) was defined as prostate-specific antigen (PSA) levels of greater than 0.2ng/ml. Results: The median age was 68 (48 to 78) and median pre-treatment PSA was 7.50 ng/ml.Average follow up period was 45.9 month. Mean tumor volume (TV) was 2.16 cc. We investigated 372 patients and found SVCa (<0.5 cc) in 60 patients (16.3%), and InsigCa in 14 patients (3.7%). The five year BCR-free survival rate for TV greater than or equal to 0.5 group and SVCa was 67.3% and 87.1% respectively. A significant difference was seen in the log-rank test between the two groups ( p=0.008). We could not identify BCR in InsigCa patients. Conclusions: Despite the limited number of cases, in our study InsigCa were clinically insignificant but in SVCa group 12.9% patients developed PSA failure after radical prostatectomy. SVCa is not identical to InsigCa. Therefore new biomarker is needed to examine what the prognostic relevance is of SVCa.