Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

A comparison of the free fraction of serum prostate specific antigen in men with benign and cancerous prostates : The best case scenario

Prestigiacomo, Anthony F. ; Lilja, Hans LU orcid ; Pettersson, Kim ; Wolfert, Robert L. and Stamey, Thomas A. (1996) In Journal of Urology 156(2). p.350-354
Abstract

Purpose: In most previous studies of free-to-total serum prostate specific antigen (PSA) ratios, the specimens from patients with prostate cancer or those with benign prostatic hyperplasia (BPH) have not been highly characterized. We compared preoperative sera from post-radical prostatectomy patients with clinically significant cancers of at least 2 cm.3 to sera from those with BPH and large, biopsy negative prostates. Materials and Methods: We used 2 different time resolved immunofluorometric assays for free and total PSA, and a combination of a chemoluminescent immunoassay for free PSA detection with an immunoradiometric assay for total PSA to measure free and total PSA. The serum ratios of free-to-total PSA in these assays... (More)

Purpose: In most previous studies of free-to-total serum prostate specific antigen (PSA) ratios, the specimens from patients with prostate cancer or those with benign prostatic hyperplasia (BPH) have not been highly characterized. We compared preoperative sera from post-radical prostatectomy patients with clinically significant cancers of at least 2 cm.3 to sera from those with BPH and large, biopsy negative prostates. Materials and Methods: We used 2 different time resolved immunofluorometric assays for free and total PSA, and a combination of a chemoluminescent immunoassay for free PSA detection with an immunoradiometric assay for total PSA to measure free and total PSA. The serum ratios of free-to-total PSA in these assays were compared to those obtained previously from gel filtration studies. Sera from 51 men with prostate cancer volumes of 2 to 18 cm.3 were compared to those from 48 men with BPH and a mean prostate volume of 78 ± 7 cm.3. The respective mean serum PSA levels plus or minus standard deviation were 10.0 ± 6.3 and 8.9 ± 7.2 ng./ml. Results: Monoclonal assays for free PSA confirmed the previous study with gel filtration. For PSA 4 to 10 ng./ml., 94 to 95% of the men with prostate cancer were correctly diagnosed, with a cutoff of less than 15% for free-to-total PSA on immunofluorometric assay and less than 14% for chemoluminescent immunoassay with immunoradiometric assay. However, 46% (immunofluorometric assay) and 36% (chemoluminescent immunoassay and immunoradiometric assay) of men with BPH did not have enough free PSA for diagnosis of BPH (that is 36 to 46% false-positive rate). Conclusions: For total PSA 4 to 10 ng./ml., the sensitivity of approximately 15% free-to-total PSA for prostate cancer is high (94 to 95%) but 36 to 46% of men with BPH and a large gland will not be correctly identified. For PSA 2 to 4 ng./ml., no ratio of percent free-to-total PSA discriminated BPH from prostate cancer.

(Less)
Please use this url to cite or link to this publication:
author
; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Prostate-specific antigen, Prostatic hypertrophy, Prostatic neoplasms
in
Journal of Urology
volume
156
issue
2
pages
350 - 354
publisher
Lippincott Williams & Wilkins
external identifiers
  • scopus:0030213487
  • pmid:8683677
ISSN
0022-5347
DOI
10.1016/S0022-5347(01)65847-6
language
English
LU publication?
yes
additional info
Funding Information: Supported in part by the Richard M. Lucas Foundation.
id
71bb10a8-7b88-4be8-afbf-d09039ed567c
date added to LUP
2022-12-06 16:35:57
date last changed
2024-06-29 01:11:06
@article{71bb10a8-7b88-4be8-afbf-d09039ed567c,
  abstract     = {{<p>Purpose: In most previous studies of free-to-total serum prostate specific antigen (PSA) ratios, the specimens from patients with prostate cancer or those with benign prostatic hyperplasia (BPH) have not been highly characterized. We compared preoperative sera from post-radical prostatectomy patients with clinically significant cancers of at least 2 cm.<sup>3</sup> to sera from those with BPH and large, biopsy negative prostates. Materials and Methods: We used 2 different time resolved immunofluorometric assays for free and total PSA, and a combination of a chemoluminescent immunoassay for free PSA detection with an immunoradiometric assay for total PSA to measure free and total PSA. The serum ratios of free-to-total PSA in these assays were compared to those obtained previously from gel filtration studies. Sera from 51 men with prostate cancer volumes of 2 to 18 cm.<sup>3</sup> were compared to those from 48 men with BPH and a mean prostate volume of 78 ± 7 cm.<sup>3</sup>. The respective mean serum PSA levels plus or minus standard deviation were 10.0 ± 6.3 and 8.9 ± 7.2 ng./ml. Results: Monoclonal assays for free PSA confirmed the previous study with gel filtration. For PSA 4 to 10 ng./ml., 94 to 95% of the men with prostate cancer were correctly diagnosed, with a cutoff of less than 15% for free-to-total PSA on immunofluorometric assay and less than 14% for chemoluminescent immunoassay with immunoradiometric assay. However, 46% (immunofluorometric assay) and 36% (chemoluminescent immunoassay and immunoradiometric assay) of men with BPH did not have enough free PSA for diagnosis of BPH (that is 36 to 46% false-positive rate). Conclusions: For total PSA 4 to 10 ng./ml., the sensitivity of approximately 15% free-to-total PSA for prostate cancer is high (94 to 95%) but 36 to 46% of men with BPH and a large gland will not be correctly identified. For PSA 2 to 4 ng./ml., no ratio of percent free-to-total PSA discriminated BPH from prostate cancer.</p>}},
  author       = {{Prestigiacomo, Anthony F. and Lilja, Hans and Pettersson, Kim and Wolfert, Robert L. and Stamey, Thomas A.}},
  issn         = {{0022-5347}},
  keywords     = {{Prostate-specific antigen; Prostatic hypertrophy; Prostatic neoplasms}},
  language     = {{eng}},
  number       = {{2}},
  pages        = {{350--354}},
  publisher    = {{Lippincott Williams & Wilkins}},
  series       = {{Journal of Urology}},
  title        = {{A comparison of the free fraction of serum prostate specific antigen in men with benign and cancerous prostates : The best case scenario}},
  url          = {{http://dx.doi.org/10.1016/S0022-5347(01)65847-6}},
  doi          = {{10.1016/S0022-5347(01)65847-6}},
  volume       = {{156}},
  year         = {{1996}},
}