A brief review of ultrasensitive prostate-specific antigen assays for the evaluation of patients after radical prostatectomy

✍ Scribed by T. K. Takayama; R. L. Vessella; P. H. Lange

• Publisher: Springer-Verlag
• Year: 1993
• Tongue: English
• Weight: 406 KB
• Volume: 11
• Category: Article
• ISSN: 0724-4983
• DOI: 10.1007/bf00185067

✦ Synopsis

The development of immunoassays for prostate-specific antigen (PSA) and their clinical utility are summarized. Because of the complexity of the PSA molecule and anti-PSA antibodies, there is currently no standard in PSA measurement [1,2]. Evaluating various immunoassays requires the knowledge of the lower limit of detection as well as the biological and clinical thresholds of a given assay [1]. There have been recent reports demonstrating earlier detection of residual prostate cancer after radical prostatectomy by ultrasensitive assays for PSA [3,4]. Because of the recent evidence for non-prostatic sources of PSA such as the male urethra [5-7], the possibility of their contaminating PSA levels must be evaluated when more sensitive assays for PSA are under consideration.

Prostate-specific antigen (PSA) was originally isolated in seminal plasma in 1971 by Hara et al. in Japan and was named gamma-seminoprotein. Since then, PSA has been called protein E1 and semen-specific protein, but in 1982, Wang et al. showed that they were all immunologically identical. Papsidero et al. then identified PSA in human serum and confirmed that it was the same molecule found in prostatic tissue. Subsequently, many studies have shown the clinical utility of PSA as a valuable tumor marker [8][9][10][11][12].

Biological characteristics

PSA is composed of 237 amino acids with a molecular weight of 34 000 Da and has considerable heterogeneity in * This work was funded in part by a grant from the American Foundation of Urologic Disease, by the American Cancer Society, by the Richard M. Lucas Cancer Foundation, and by the Veterans Administration.