Purpose: Gleason score is the dominant predictor of the outcome in patients who diagnosed to have prostate cancer. In this retrospective study we tried to find out preoperative variables which significantly correlate with gleason scores.
Material and methods: Between January 2005 and May 2008 total of 288 patients with mean age of 66.62 years (range; 44-81) who had prostate specific antigens (TPSA) between 4-10 ng/ml and underwent 10-core transrerectal ultrasound-guided biopsy were enrolled. Digital rectal examination (DRE), TPSA, total prostate volume, PSA density were determined for all patients. Each biopsy specimen was assessed for tumor involvement by calculating the percent of cores positive for cancer, percent of positive tissue involved in all cores and Gleason score. Mean value of TPSA, PSA density were 6.7 + 1.5 ng/ml and 15.95 + 10.49ng/ml/cc respectively.
Results: None of the pre biopsy variables had significant correlation with gleason score, however, PSA value had correlation with positive tissue at cores (p<0.05). Gleason score correlated significantly with percentage of positive numbers of cores, positive tissue at biopsy material and neural invasion (p=0.001). Percentage of positive number of cores was in correlation of neural invasion (p=0.001). TPSA, PSA density and DRE were predictors of prostate cancer detection (ROC curve, 0.57, 0.70,0.59 respectively).
Conclusion: Pre-biopsy parameters failed to predict gleason score. Patients with high numbers of positive cores should not be candidate for nerve sparing surgery. Histologic report should include determination of percentage positive number of cores and positive tissue.