Percent of cancer in the biopsy set predicts pathological findings after prostatectomy

Abstract

Purpose: The ability to use pretreatment variables to identify patients with organ confined prostate cancer continues to challenge physicians. We examined information available preoperatively, including prostate needle biopsy, clinical stage and preoperative prostate specific antigen (PSA), and evaluated these data based on pathological variables after radical retropubic prostatectomy.

Materials and methods: We reviewed results in 135 consecutive patients who underwent radical retropubic prostatectomy at a single institution. Needle biopsy information, such as the number of cores, percent of tumor per biopsy set, laterality of positive cores and Gleason sum, were compared with pathological data on the radical retropubic prostatectomy specimen, including pathological stage, Gleason sum and tumor volume. Clinical data, including biopsy information and pathological findings, were compared using univariate and multivariate models.

Results: Overall total PSA, percent of tumor in the biopsy and bilateral positive cores directly correlated with tumor volume (p <0.01). Also, increasing PSA, increasing percent of tumor in the biopsy and bilateral positive cores were associated with increased risks of extracapsular extension (p <0.01).

Conclusions: From the information readily available from prostate needle biopsy these results suggest that percent of tumor in the biopsy is a useful predictor of pathological stage and tumor volume. Furthermore, including percent of tumor in the biopsy set and bilateral disease with traditional variables such as serum PSA and clinical stage may improve pretreatment tumor staging. This finding adds additional credence to the inclusion of percent of tumor in the biopsy set in models for the preoperative prediction of pathological stage and should be factored into discussions with patients on treatment options.