The role of PSA density to predict a pathological tumour upgrade between needle biopsy and radical prostatectomy for low risk clinical prostate cancer in the modified Gleason system era

Abstract

We evaluate the role of prostate-specific antigen (PSA) density to predict Gleason score upgrade between prostate biopsy material and radical prostatectomy specimen examination in patients with low-risk prostate cancer. Between January 2007 and November 2011, 133 low-risk patients underwent a radical prostatectomy. Using the modified Gleason criteria, tumour grade of the surgical specimens was examined and compared to the biopsy results. A tumour upgrade was noticed in 57 (42.9%) patients. Organ-confined disease was found in 110 (82.7%) patients, while extracapsular disease and seminal vesicles invasion was found in 19 (14.3%) and 4 (3.0%) patients, respectively. Positive surgical margins were reported in 23 (17.3%) patients. A statistical significant correlation between the preoperative PSA density value and postoperative upgrade was found (p = 0.001) and this observation had a predictive value (p = 0.002); this is in contrast to the other studied parameters which failed to reach significance, including PSA, percentage of cancer in biopsy and number of biopsy cores. Tumour upgrade was also highly associated with extracapsular cancer extension (p = 0.017) and the presence of positive surgical margins (p = 0.017). PSA density represents a strong predictor for Gleason score upgrade after radical prostatectomy in patients with clinical low-risk disease. Since tumour upgrade increases the potential for postoperative pathological adverse findings and prognosis, PSA density should be considered when treating and consulting patients with low-risk prostate cancer.