WASHINGTON, DC USA (UroToday.com) - Using biopsy data from active surveillance (AS) patients, these investigators importantly show that prostate hemiablation should not rely on one set of prostate biopsies for adequate tumor localization and characterization.
Hemiablation is a minimally invasive treatment option for men with prostate cancer on AS. Of concern with this approach is the possibility of missing an undiagnosed cancer or the growth of a new cancer in another part of the gland. The study aim was to investigate initial positive and repeat TRUS-BX findings in men on AS to determine how often and to what extent an altered disease profile occurred on second biopsy. They also sought to determine histologic predictors of subsequent cancer occurrence in non-cancerous areas. The study was derived from a prospective database of all patients undergoing prostate biopsy. Three radiologists performed all biopsies using a systematic 11-core initial and 15 core repeat biopsy approach. A total of 423 AS patients were identified who had at least 2 biopsies. AS inclusion criteria were; <3 cores positive, less than 50% of any core positive, <7 Gleason score. They compared the site of occurrence of cancer between the first biopsy and second biopsy. Histologic predictors of contralateral cancer occurrence and worsening disease grade were also assessed.
The median time between biopsies was 14 months with a decrease in mean PSA from 7.3 to 7.0 (p<0.01). On second biopsy, 17% of men had an increase in Gleason score, 49% had no change and 35% had no cancer detected. The mean number of positive cores decreased on second biopsy from 1.9 to 1.4 (p<0.01). Cancer position on second biopsy remained the same in 36%, occurred on the contralateral side in 29%, and was undetectable in 35%. The only predictor of cancer occurrence on the contralateral side on second biopsy was having contralateral ASAP or HGPIN on the first biopsy (OR 1.82, p=0.02). Having >1 core positive on first biopsy was a predictor of higher-grade disease on the second biopsy (OR 2.54; p<0.01). They concluded that follow-up prostate biopsy in men on AS can uncover cancers in the contralateral part of the gland in approximately one third of cases with the only pathologic predictors being ASAP or HGPIN in the contralateral area. They translated their data to suggest that prostate hemiablation should not rely on one set of prostate biopsies.
Presented by Greg Trottier, et al. at the American Urological Association (AUA) Annual Meeting - May 14 - 19, 2011 - Walter E. Washington Convention Center, Washington, DC USA
Reported for UroToday by Christopher P. Evans, MD, FACS, Professor and Chairman, Department of Urology, University of California, Davis, School of Medicine.