Procoagulant properties of benign and malignant prostatic tissue.
OBJECTIVE: To determine the factor-X activating procoagulant activity (FXAA) of prostatic tissue removed at transurethral resection in a specific chromogenic assay. PATIENTS AND METHODS: FXAA was extracted from transurethrally resected prostatic tissue using a cryofragmentation technique. Tissue from 50 patients with prostate cancer was analysed and compared with that from 36 control patients with benign prostatic-hypertrophy. Enzyme activities were assayed in a two stage chromogenic assay and correlated with conventional markers of tumour aggressiveness. RESULTS: FXAA was found to be significantly lower (P < 0.001) in tissue from malignant prostates compared with benign prostatic hypertrophy tissue. Loss of FXAA was also related to Gleason grade (P < 0.03), percentage of chips involved by tumour (P < 0.04) and bone scan status (P < 0.02). Using antibody inhibition tests this procoagulant was characterized as being a factor VII/tissue factor complex. CONCLUSIONS: Malignant change in the prostate is associated with a reduction in FXAA and this may be an important factor in prostatic tumour growth and dissemination.