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Metabolism of free and complexed prostate - specific antigen and their utility for diagnosis and prognosis of prostate cancer

Björk, Thomas LU (1998)
Abstract
Prostate-specific antigen (PSA) is a glycoprotein produced by the prostate gland. It occurs in several molecular forms in the blood and assays have been developed to measure free PSA and PSA in complex with alpha-1-antichymotrypsin (PSA-ACT). Higher proportions of free PSA (PSA-F/T) in blood are found in subjects with benign prostatic hyperplasia (BPH) as compared to cancer patients. Utilizing immunocytochemistry and in situ hybridization we demonstrated production of PSA and ACT in normal and malignant prostatic tissue. In areas with BPH however, only PSA was detected, which may be linked to the differences in proportions of PSA-F/T found in blood from patients with cancer compared to subjects with BPH. Comparing selective measurements of... (More)
Prostate-specific antigen (PSA) is a glycoprotein produced by the prostate gland. It occurs in several molecular forms in the blood and assays have been developed to measure free PSA and PSA in complex with alpha-1-antichymotrypsin (PSA-ACT). Higher proportions of free PSA (PSA-F/T) in blood are found in subjects with benign prostatic hyperplasia (BPH) as compared to cancer patients. Utilizing immunocytochemistry and in situ hybridization we demonstrated production of PSA and ACT in normal and malignant prostatic tissue. In areas with BPH however, only PSA was detected, which may be linked to the differences in proportions of PSA-F/T found in blood from patients with cancer compared to subjects with BPH. Comparing selective measurements of the PSA forms and their ratios by receiver operating characteristics showed that PSA-F/T best discriminated cancer from BPH in patients with normal or slightly elevated PSA levels. After removal of the prostate the elimination of free PSA was bi-exponential with an initial, rapid re-distribution phase followed by a terminal phase with a half-life of 14 hours. PSA-ACT was eliminated slowly and non-exponentially with a mean rate of 0.8 ng/mL/day indicating a capacity-limited process. In hormonally deprived patients with high pre-treatment PSA concentrations, both free PSA and PSA-ACT were eliminated exponentially with mean half-lives of 10 and 13 days respectively. In 66 prostate cancer patients followed until death or for a minimum of nine years, univariate analysis showed that all PSA forms, but not their ratios, as well as tumour grade, local and distant stage gave prognostic information on cancer survival. In a multivariate analysis with step-wise entering of factors only grade, distant stage and the PSA-F/PSA-ACT ratio provided prognostic information. (Less)
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author
supervisor
opponent
  • Prof Jan-Erik, Jan-Erik, Umeå
organization
publishing date
type
Thesis
publication status
published
subject
keywords
benign prostatic hyperplasia, alpha-1-antichymotrypsin, PSA, prostate cancer, prostate-specific antigen, Urology, nephrology, Urologi, nefrologi
pages
142 pages
publisher
Department of Urology, Malmö University Hospital, 205 02 Malmö, Sweden
defense location
Malmö University Hospital, MFC, entrance 59
defense date
1998-05-02 10:00:00
external identifiers
  • other:ISRN: LUMEDW/MESM-1070-SE
ISBN
91-628-2979-3
language
English
LU publication?
yes
additional info
The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Urology (013243400), Division of Urological Cancers (013243420)
id
8dc89203-ecf3-48fa-83de-01b7cb650475 (old id 38537)
date added to LUP
2016-04-04 10:07:49
date last changed
2018-11-21 20:56:56
@phdthesis{8dc89203-ecf3-48fa-83de-01b7cb650475,
  abstract     = {{Prostate-specific antigen (PSA) is a glycoprotein produced by the prostate gland. It occurs in several molecular forms in the blood and assays have been developed to measure free PSA and PSA in complex with alpha-1-antichymotrypsin (PSA-ACT). Higher proportions of free PSA (PSA-F/T) in blood are found in subjects with benign prostatic hyperplasia (BPH) as compared to cancer patients. Utilizing immunocytochemistry and in situ hybridization we demonstrated production of PSA and ACT in normal and malignant prostatic tissue. In areas with BPH however, only PSA was detected, which may be linked to the differences in proportions of PSA-F/T found in blood from patients with cancer compared to subjects with BPH. Comparing selective measurements of the PSA forms and their ratios by receiver operating characteristics showed that PSA-F/T best discriminated cancer from BPH in patients with normal or slightly elevated PSA levels. After removal of the prostate the elimination of free PSA was bi-exponential with an initial, rapid re-distribution phase followed by a terminal phase with a half-life of 14 hours. PSA-ACT was eliminated slowly and non-exponentially with a mean rate of 0.8 ng/mL/day indicating a capacity-limited process. In hormonally deprived patients with high pre-treatment PSA concentrations, both free PSA and PSA-ACT were eliminated exponentially with mean half-lives of 10 and 13 days respectively. In 66 prostate cancer patients followed until death or for a minimum of nine years, univariate analysis showed that all PSA forms, but not their ratios, as well as tumour grade, local and distant stage gave prognostic information on cancer survival. In a multivariate analysis with step-wise entering of factors only grade, distant stage and the PSA-F/PSA-ACT ratio provided prognostic information.}},
  author       = {{Björk, Thomas}},
  isbn         = {{91-628-2979-3}},
  keywords     = {{benign prostatic hyperplasia; alpha-1-antichymotrypsin; PSA; prostate cancer; prostate-specific antigen; Urology; nephrology; Urologi; nefrologi}},
  language     = {{eng}},
  publisher    = {{Department of Urology, Malmö University Hospital, 205 02 Malmö, Sweden}},
  school       = {{Lund University}},
  title        = {{Metabolism of free and complexed prostate - specific antigen and their utility for diagnosis and prognosis of prostate cancer}},
  year         = {{1998}},
}