Stratification of pathologic features in radical prostatectomy specimens that are predictive of elevated initial postoperative serum prostate-specific antigen levels.

Abstract

Prostate-specific antigen (PSA) is an important marker for adenocarcinoma of the prostate and is of clinical utility in assessment of residual carcinoma after radical prostatectomy. Although elevated postoperative serum PSA levels have been linked to pathologic stage in radical prostatectomy specimens, limited data are available on the relationship of postoperative PSA levels to margin positivity, intraglandular tumor extent, and histologic grade. Initial postoperative serum PSA levels were related to pathologic features of 90 radical prostatectomy specimens with adenocarcinoma of the prostate. Logistic regression analysis was used to stratify pathologic stage, percentage intraglandular carcinoma, histologic grade, and margin positivity as predictors of elevated initial postoperative PSA levels. Pathologic stage, percentage carcinoma, and margin positivity were nearly equivalent in strength of prediction, whereas Gleason histologic grade was a significant but less reliable predictor of elevated initial postoperative PSA levels. Thirty-one of 51 (60.8%) patients with extension of carcinoma outside the prostate gland had an elevated initial postoperative PSA level, whereas only 5 of 39 (12.8%) patients with organ-confined carcinoma had an elevated postoperative PSA level. Intraglandular tumor extent greater than 10% was associated with a greater likelihood of an elevated postoperative PSA level. Additional predictive capacity was obtained with concurrent use of pathologic stage and percentage carcinoma or margin positivity in multivariate analysis. In radical prostatectomy specimens, pathologic stage, intraglandular carcinoma extent, and margin positivity are particularly important morphologic parameters because they are predictive of residual carcinoma that is detected early, as judged by an elevated initial postoperative serum PSA level.