There is no way to identify patients who will harbor small volume, unilateral prostate cancer at final pathology. implications for focal therapies.

Background: The aim of this study was to assess the clinical characteristics of the potentially ideal candidates for focal therapy, that is, patients with unilateral, small volume (namely, pT2a) prostate cancer (PCa) at radical prostatectomy (RP).
Materials and Methods: We evaluated 2,503 consecutive pT2 PCa patients treated with RP between 2002 and 2009 at a single center. Within this population, the clinical characteristics of patients with pT2a and pT2b/c disease were compared. Univariable and multivariable logistic regression models were fitted to assess clinical predictors of pT2a at RP.
Results: Overall, 349 patients (14%) had pT2a PCa, while the remaining patients had either pT2b (n = 334; 15.5%) or pT2c disease (n = 1,820 patients; 84.5%). Patients with pT2a PCa had a significantly lower mean PSA value, lower mean percentage of positive biopsy cores and lower biopsy Gleason score distribution (all P ≤ 0.03). However, at multivariable analyses, only percentage of positive cores maintained an independent predictor status (P = 0.01). Even when considering only patients sharing all the most favorable PCa characteristics (namely, clinical stage T1, PSA ≤ 4, Gleason score ≤6 and percentage of positive cores ≤25%), the rate of pT2a disease was only 24%.
Conclusions: The rate of small volume, unilateral PCa even among patients with extremely favourable PCa characteristics was remarkably low (roughly 25%). This suggests that: (1) Three quarters of the best candidates for focal therapy would ultimately show adverse pathological features; (2) At present, accurate identification of the ideal candidate for focal therapy is not possible with current clinical-pathologic parameters.
(Copyright © 2011 Wiley Periodicals, Inc.)