COMPARISON OF PROSTATE-SPECIFIC ANTIGEN, PROSTATE-SPECIFIC MEMBRANE ANTIGEN, AND LNCAP-BASED ENZYME-LINKED IMMUNOSORBENT ASSAYS IN PROSTATIC-CANCER PATIENTS AND PATIENTS WITH BENIGN PROSTATIC ENLARGEMENT

Serum assays for prostate specific antigen (PSA; monoclonal), for pros tate specific membrane antigen (PSM; Western blot), and a LNCaP/7E11.C 5-based competitive enzyme-linked immunosorbent assay (ELISA) were eva luated in a small number of prostate cancer patients with localized or disseminated disease, and judged to be in clinical progression or rem ission based on National Prostate Cancer Project (NPCP) criteria. PSA values recognized the presence of clinical progression in localized di sease (B-1-C) and to a lesser degree disseminated disease (D-1-D-2). I n contrast, to a Limited degree the ELISA test recognized clinical pro gression mainly in disseminated disease and chiefly in stage D-2. PSM values were elevated in both D-1 and D-2 but not in a linear fashion a s observed with PSA. The ELISA and PSM results may be assessing a diff erent clinical response to prostatic cancer than that recognized by PS A. This could reflect a developing clone of resistant prostatic cells as previously postulated. To further pursue this possibility a seconda ry generation of monoclonal antibodies to PSM is being developed. The ELISA levels for benign prostatic enlargement were not elevated above normal. In contrast both with PSA and PSM the assays reflected levels significantly above the normal range in benign prostatic hypertrophy ( BPH). (C) 1995 Wiley-Liss, Inc.