Tissue PSA from fine-needle biopsies of prostatic carcinoma as related to serum PSA, clinical stage, cytological grade, and DNA ploidy

BACKGROUND. The mechanisms behind changes in serum PSA (S-PSA) levels in patients with prostatic carcinoma (CAP) are not completely known. To further elucidate the factors affecting the serum levels of this important tumor marker, we measured PSA concentrations in serum and in aspiration biopsies (tissue PSA; T-PSA) from patients with prostatic disease and correlated the values to tumor stage, cytological grade, and DNA ploidy. METHODS. T-PSA and S-PSA were measured in 91 metastasis-free patients with newly diagnosed, untreated CAP and 13 patients with benign prostatic hyperplasia, and the values were related to tumor stage, cytological grade, and DNA ploidy. RESULTS. Significant negative correlations were found between T-PSA and S-PSA in the total clinical material and various subgroups of patients with CAP T-PSA showed significant negative associations to T-stage and to cytological grading, and T-PSA concentrations were significantly lower in tetra-/aneuploid tumors than in diploid tumors. On the other hand, S-PSA showed corresponding positive associations and was significantly higher in tetra-/aneuploid tumors than in diploid tumors. CONCLUSIONS. The negative association between S-PSA and T-PSA values indicates that S-PSA values in metastasis-free patients reflect the degree of leakage from the tumor tissue rather than the intracellular concentration of PSA. Factors such as tissue volume, condition of gland structure, and vascularization may thus be more important for S-PSA than the production of PSA in the prostatic tissue. (C) 1999 Wiley-Liss, Inc.