DETECTION OF PROSTATIC CELLS IN PERIPHERAL-BLOOD - CORRELATION WITH SERUM CONCENTRATIONS OF PROSTATE-SPECIFIC ANTIGEN

We have studied the expression of prostate-specific antigen (PSA) mRNA by reverse transcriptase-polymerase chain reaction in peripheral bloo d of 25 patients with cancer of the prostate (CAP), four with benign p rostatic hyperplasia (BPH), two with renal stones, three with other ty pes of cancer, and six healthy male and three female controls. Express ion of mRNA specific for a certain tissue in peripheral blood is thoug ht to indicate the presence of circulating cancer cells and metastatic spread of a tumor originating from this tissue. We detected PSA mRNA in 9 of 18 CAP patients with metastatic disease but in none of 7 patie nts without metastases. Negative results in patients with metastatic d isease were associated with successful endocrine therapy and low conce ntrations of serum PSA and the correlation between serum concentration s of PSA and the presence of PSA mRNA in peripheral blood was statisti cally significant. PSA mRNA was not found in patients with BPH, other types of cancer, or in healthy controls. Thus the occurrence of PSA mR NA in peripheral blood is associated with metastatic CAP.