Correlation between preoperative predictors and pathologic features in radical prostatectomy specimens in PSA-based screening.

Abstract

Measurement of percent free prostate-specific antigen (PSA), PSA density, and PSA-transition zone density (PSA-TZ density) in addition to total PSA is known to improve the specificity of PSA-based prostate cancer screening. We evaluated the ability of total PSA, percent free PSA, PSA density, and PSA-TZ density to predict pathologic features in radical prostatectomy specimens. The levels of total PSA, percent free PSA, PSA density, and PSA-TZ density assessed prior to the diagnosis of prostate cancer were correlated with the pathologic findings in 102 prostate glands with cancer obtained at radical prostatectomy. The entire organs were examined histologically; Pearson correlation coefficients were used for statistical analysis. High levels of total PSA, PSA density, and PSA-TZ density correlated significantly with capsular penetration, high Gleason scores, and large cancer volumes in the prostatectomy specimens. Free PSA was found to correlate well with high Gleason scores, high percentages of cancer, and large cancer volumes, but not with capsular penetration. The four parameters were evaluated by means of logistic regression, which showed that only percent free PSA and total PSA were significant predictors of Gleason scores > or =7 and cancer volumes > or =0.5 cc. With regard to clinically insignificant cancers, only percent free PSA and the Gleason score obtained at biopsy were significant predictors. In men whose prostate cancers are detected by PSA-based screening, high total PSA levels in combination with low percent free PSA levels are suggestive of a potentially more aggressive type of prostate cancer. This may help both patient and clinician in selecting the most appropriate therapeutic approach.