Identifying candidates for active surveillance: an evaluation of the repeat biopsy strategy for men with favorable risk prostate cancer.

PURPOSE: Active surveillance is increasingly recommended to reduce overtreatment in men with favorable risk prostate cancer. A repeat confirmatory biopsy has become the standard recommendation for these men to increase the precision of this risk attribution. We investigate the usefulness of this approach by comparing the current practice standard, repeat transrectal ultrasound biopsy, with template prostate mapping. MATERIALS AND METHODS: A total of 124 men who were attributed a favorable risk prostate cancer status based on transrectal ultrasound guided biopsy and who were considering a policy of active surveillance underwent combined transrectal ultrasound biopsy and template prostate mapping as a confirmatory strategy. Maximum Gleason grade and disease burden were compared between the 2 confirmatory tests. RESULTS: Depending on the definition used between 8% and 22% of men had prostate cancer reclassified as clinically important by repeat transrectal ultrasound biopsy whereas template guided prostate mapping reclassified the disease in 41% to 85% of the men. Repeat transrectal ultrasound biopsy failed to detect up to 80% of clinically important cancers detected by the reference standard. The sensitivity of repeat transrectal ultrasound biopsy to identify clinically important disease varied from 9% to 24% with the negative predictive value ranging from 23% to 60%. CONCLUSIONS: When applied to a population of men initially deemed to have favorable risk prostate cancer, transrectal ultrasound biopsy will miss a large proportion of clinically important cancers compared to template guided prostate mapping. The usefulness of repeat transrectal ultrasound biopsy in ruling out clinically important prostate cancer needs to be reconsidered.

Appropriate patient selection in the focal treatment of prostate cancer: the role of transperineal 3-dimensional pathologic mapping of the prostate--a 4-year experience.

This study was undertaken to evaluate the usefulness of transperineal mapping biopsy of the prostate as a staging procedure in the appropriate selection of patients for treatment with focal cryoablation. Between October 2001 and January 2006, a total of 80 patients underwent extensive template-guided transperineal pathologic mapping of the prostate (3-DPM), in conjunction with repeat transrectal ultrasound (TRUS)-guided biopsies. Before 3-DPM was performed, the following clinical variables were recorded: age, prostate-specific antigen (PSA), percent free PSA, total prostate volume, transition zone volume, Gleason score, TNM stage, number of positive cores, and maximum percent of positive cores. Results of 3-DPM were compared with those of TRUS-guided biopsies to determine patient suitability for focal cryoablation; this served as the study end point. Of 80 study patients, 43 (54%) were deemed unsuitable for focal cryoablation. When compared with 3-DPM in assessing patient suitability for focal cryoablation repeat TRUS-guided biopsies yielded a false-negative rate of 47%, a sensitivity of 54%, and a negative predictive value of 49%. None of the pre-3-DPM variables correlated significantly with patient suitability for focal ablation. Treatment selected by the 80 study patients included total gland cryoablation (30%), expectant management (23%), radical prostatectomy (18%), focal cryoablation (11%), external irradiation (10%), brachytherapy (6%), and combined external irradiation and brachytherapy (1%); 1% were undecided about treatment selection. In this study, we demonstrated that 3-DPM (1) effectively excluded patients with clinically significant unsuspected cancer outside the area destined to be ablated, (2) appeared to do so more effectively than repeat TRUS-guided biopsies, and (3) was able to precisely locate the site of the cancer to be selectively ablated.