Background: The introduction of minimally invasive ablative procedures such a cryotherapy or HIFU for the treatment of prostate cancer (PCa) challenges urologic oncologists to define clinical and pathologic criteria to select candidates for focal therapy. From this standpoint, we evaluated distinctions between the biological behavior of uni- vs. bilateral tumors in order to better select patients for unilateral ablation.

Methods: Analysis included demographic, clinical and pathologic parameters of 1184 men who underwent radical prostatectomy for early stage localized prostate cancer at our institution between 2002 and 2006. Final pathology assessment was done with particular attention to laterality and percentage of tumor involvement (PTI) along with other routine parameters. Based on PTI all cancer foci were ranked as ≤5, 6-10,11-15 and >15%). Statistical analysis was done using univariate (Chi-square test) and multivariate methods (Cox regression model) using SPSS program, version 12 (Chicago , IL).

Results: Biochemical recurrence was diagnosed in 164 (13.9%) of 1184 patients. The distribution of recurrent patients between unilateral and bilateral tumors was 26 (15.9%) versus 138 (84.1%), respectively (p=0.25). The most common characteristics associated with unilateral tumors in Cox model were a diagnostic PSA level, prostate weight and pathologic Gleason Score (pGS) (p<0.0005).

Conclusions: Uni-or bilateral tumors within the prostate did not predict biochemical recurrence after radical prostatectomy. In contrast, baseline PSA level and pGS strongly predicted PSA recurrence. Therefore, a diagnostic PSA level may be clinically used to select patients for focal thermoablation.