Are more low-risk prostate cancers detected by repeated biopsy? A retrospective pilot study

We hypothesized that there might be a higher incidence of low-risk prostate cancer (PCa) in men diagnosed at a repeated biopsy. Thus, we investigated differences in clinicopathological results of PCa after primary and repeated biopsy.

We retrospectively reviewed patients diagnosed with PCa at a primary or repeated biopsy from January 2004 to April 2011. Patients were stratified into primary biopsy and repeated biopsy groups. We analyzed prostate-specific antigen, clinical stage, Gleason score (GS), positive core ratio, and low-risk group by using D'Amico classification. We also investigated GS upgrading and upstaging after radical prostatectomy (RP).

Among 448 primary and 37 repeated biopsy PCa patients, 82 (group 1) and 25 (group 2) underwent RP. The percentage of low-risk patients did not differ significantly between the groups. The positive biopsy core ratio was significantly lower in group 2 (p=0.009). The percentages of GS upgrading and upstaging were 42.7% and 47.6% in group 1, respectively (p=0.568), and 48.0% and 52.0% in group 2, respectively (p=0.901). In the analysis of low-risk patients, GS upgrading and upstaging were not significantly different between the groups (p=0.615 and p=0.959, respectively).

A lower positive core ratio may imply a small volume of PCa and possibly insignificant PCa in the repeated biopsy group. However, no significant differences were observed for the ratio of low-risk cancers, GS upgrading, or upstaging between the groups. Therefore, PCa diagnosed at a repeated biopsy is not an additional indication for active surveillance.