Pathologic basis of focal therapy for early-stage prostate cancer.

The treatment paradigm for small-volume, low-grade unifocal or unilateral prostate cancer is shifting from a radical, whole-gland approach toward organ-sparing, focal ablation. The widely implemented screening program in the US has detected small-volume prostate lesions at early stages of carcinogenesis, which has enabled the shift in treatment paradigm. An image-guided approach to focal therapy has yet to be realized, and is dependent on the development of an imaging modality that detects cancer with high sensitivity and specificity. The future success of focal therapy will depend on adequate prostate sampling at biopsy, along with accurate characterization of the spatial distribution of tumor within the prostate. The pathologic evaluation of radical prostatectomy specimens remains of paramount importance, as this reference standard can validate all preoperative clinical, demographic, laboratory, imaging and prostate biopsy findings.