UNDETECTABLE SERUM PROSTATE-SPECIFIC ANTIGEN ASSOCIATED WITH METASTATIC PROSTATE-CANCER - A CASE-REPORT AND REVIEW OF THE LITERATURE

A 63-year-old man, who had undergone prostatectomy for prostate cancer that was positive for prostate-specific antigen (PSA) was examined an d found to have metastatic disease, proven radiologically and patholog ically, but with an undetectable PSA and highly elevated prostatic aci d phosphatase (PAP). Prostatic acid phosphatase levels fell in respons e to chemotherapy but his clinical status continued to deteriorate. A review of the literature is presented and several possible explanation s for PSA remaining undetectable in these situations are discussed. Th e authors conclude that although PSA can be used to monitor the majori ty of patients postprostatectomy, physicians may still need to rely on clinical suspicion, serum PAP, and bone scan for the detection of rec urrent disease.