Preoperative prostate needle biopsy p27 correlates with subsequent radical prostatectomy p27, Gleason grade and pathological stage

Abstract

Purpose: Loss of p27 protein expression in radical prostatectomy specimens has been shown to be an adverse prognostic factor in patients with clinically localized prostate cancer. To our knowledge no studies have examined p27 expression in prostate needle biopsies. To test the potential predictive power of p27 in prostate biopsies we compared p27 expression in preoperative biopsies and matched prostatectomy specimens of patients with clinically localized prostate cancer.

Materials and methods: Matched biopsies and radical prostatectomy specimens from 44 patients were examined. Mean followup was 22.7 months (range 1 to 46). Tumors expressing less than 30% positive nuclei were classified as low expressors and tumors expressing greater than 30% positive nuclei were classified as high expressors of p27 protein.

Results: Expression of p27 in prostate biopsies correlated significantly with subsequent p27 expression in radical prostatectomy specimens (p = 0.002). Sensitivity and specificity of biopsy p27 for predicting subsequent prostatectomy p27 were 87.5% and 88.9%, respectively (p <0.001). Univariate analysis showed that low expression of p27 in the biopsy correlated significantly with biopsy and prostatectomy Gleason score (p = 0.000 and 0.001, respectively), and final pathological stage (p = 0.028). Despite the small sample size and short followup, 36.4% of patients with low p27 expression had a biochemical recurrence compared to only 12.1% with high expression (hazards ratio 3.56). In addition, Kaplan-Meier analysis suggested that low p27 expression in prostate biopsies may be associated with a shorter time to recurrence, although this did not reach statistical significance (p = 0.081).

Conclusions: Expression of p27 in prostate biopsies can be used to predict the degree of expression in radical prostatectomy specimens. As loss of p27 protein expression in prostatectomy specimens has been shown to correlate with biochemical recurrence and shortened prostate specific survival, these results suggest that biopsy p27 may help identify high risk patients preoperatively.