MOLECULAR-FORMS OF PROSTATE-SPECIFIC ANTIGEN AND HUMAN KALLIKREIN-2 (HK2) IN URINE ARE NOT CLINICALLY USEFUL FOR EARLY DETECTION AND STAGING OF PROSTATE-CANCER

Objectives. Prostate-specific antigen (PSA), a member of the human kal likrein (hK) family, is the most important tumor marker for early dete ction, staging, and monitoring of men with prostate cancer today. Howe ver, the sensitivity of serum PSA is not sufficient to be used alone f or prostate cancer screening. Recently, it was reported that the serum -to-urinary total PSA ratio improves the detection of men with prostat e cancer, especially in men with a serum total PSA level between 4.0 a nd 10.0 ng/mL. We tested this hypothesis by evaluating the clinical us efulness of this PSA ratio as well as the use of the different molecul ar forms of PSA and human kallikrein 2 (hK2) in urine for detection an d staging of prostate cancer. Methods. One hundred ten fresh, midstrea m urine specimens (prostate cancer 62, benign prostatic hyperplasia [B PH] 38, healthy male control 5, women 5) were collected. Serum total P SA, urine total PSA, urinary free PSA, urinary alpha(1)-antichymotryps in-bound PSA, and urinary hK2 levels were determined by monoclonal ant ibody assays (Hybritech Inc.). The serum-to-urinary total PSA ratio wa s calculated. Results. The serum-to-urinary total PSA ratio did not ac curately distinguish between men with BPH and men with prostate cancer . There was no significant difference between the urinary levels of an y of the molecular forms of PSA or hK2 between men with prostate cance r and men with BPH. Among men with prostate cancer, neither urinary hK 2 nor urinary levels of any of the molecular forms of PSA correlated w ith age, pathologic stage, or Gleason grade. Conclusions. In our study , the serum-to-urinary total PSA ratio did not improve the detection o f men with prostate cancer. Furthermore, measurement of the molecular forms of PSA and hK2 in urine did not improve the detection or staging of prostate cancer over serum PSA alone. (C) 1997, Elsevier Science I nc. All rights reserved.