Trends in pathologic outcomes after introduction of active surveillance in the UK: implication for focal therapy.

BACKGROUND: We aimed to evaluate the trends in pathologic outcomes of clinically localized prostate cancer treated with radical prostatectomy prior to and after national guidelines placing active surveillance as the primary management in men with low-risk prostate cancer. Further, we examined whether there was a coincident change in the proportion of men potentially suitable for focal therapy. METHODS: All cancer foci in 195 whole mount radical prostatectomy samples during two periods (Period 1: 07/2001-10/2003, n = 100 and Period 2: 01/2007-11/2009, n = 95) were examined. Individual tumor volumes, Gleason grade, and extracapsular extension/positive surgical margins were evaluated. The index lesion was defined as the largest by volume. RESULTS: There was a statistically significant increase in the proportion of Gleason score ≥7 tumors (31-69%; P < 0.001) and pathologically non-organ confined disease (21-37%; P = 0.008), between period 1 and 2, respectively. The proportion of patients with unifocal prostate cancer potentially suitable for focal ablation was stable (14-13.7%; P = 0.9). Although there was a decrease in the proportion of patients potentially suitable for index lesion ablation (51-43%; P = 0.4) and unilateral prostate cancer potentially suitable for hemi-ablation (11-6.3%; P = 0.3), these differences were not statistically significant. CONCLUSION: The increasing use of active surveillance in the UK may be responsible for a trend towards higher grade and stage prostate cancer in whole mount specimens. Despite this, there remain a significant proportion of men who currently undergo radical surgery who may be suitable for focal therapy, if that included index lesion ablation.