1. |
- Tornblom, M, et al.
(author)
-
Diagnostic value of percent free prostate-specific antigen: retrospective analysis of a population-based screening study with emphasis on men with PSA levels less than 3.0 ng/mL
- 1999
-
In: Urology. - 1527-9995 .- 0090-4295. ; 53:5, s. 945-950
-
Journal article (peer-reviewed)abstract
- OBJECTIVES: To retrospectively investigate the use of percent free prostate-specific antigen (PSA) compared with total PSA in serum as predictor of prostate cancer in men selected randomly from the general population who underwent biopsy on the basis of abnormal findings on digital rectal examination (DRE) or transrectal ultrasound (TRUS) and/or serum PSA levels greater than 10 ng/mL. METHODS: A single intervention, population-based screening study was undertaken in 1988 and 1989. Of the 2400 men aged 55 to 70 years invited to participate, 1782 men responded and were examined with DRE, TRUS, and PSA testing (Tandem-Hybritech). In 1995, frozen serum samples from 1748 men were analyzed for percent free PSA (Prostatus, Wallac OY). Five-year follow-up data on new cancers in the screened population were obtained from the Swedish Cancer Registry (SCR). RESULTS: Of the 1748 men, 367 underwent TRUS-guided biopsies because of abnormal findings on either DRE or TRUS or serum PSA levels of greater than 10 ng/mL. This resulted in the diagnosis of 64 cases of prostate cancer (3.7%). PSA levels of 3.0 ng/mL or greater were found in 55 (86%) of 64 cancer cases and in 399 (24%) of the 1684 benign cases. Among the 1294 men with PSA less than 3.0 ng/mL, 9 prostate cancers were diagnosed (14% of all prostate cancers). All 9 patients with cancer and with PSA less than 3.0 ng/mL had a percent free PSA of 18% or less. In the group of 1109 patients with PSA less than 3.0 ng/mL and a percent free PSA greater than 18%, 159 biopsies were performed because of abnormal DRE or TRUS. However, no prostate cancer was diagnosed in this category of patients. Five years after the screening intervention, 7 more cases of prostate cancer were clinically diagnosed in the screened population according to the SCR. CONCLUSIONS: The combination of PSA levels less than 3.0 ng/mL and percent free PSA greater than 18% defines a large part of the population at a very low risk of cancer of the prostate both at the time of screening and during the following 5 years. Men in this group may be spared DRE, and longer screening intervals may be considered. However, the risk of having prostate cancer is not negligible in men with PSA less than 3.0 ng/mL and percent free PSA of 18% or less. The results of this study indicate that biopsy should be recommended to men fulfilling these criteria, although these results should be confirmed in larger prospective studies because of the limited number of patients with prostate cancer in the present series.
|
|
2. |
|
|
3. |
|
|
4. |
|
|
5. |
|
|
6. |
- Angelopoulou, Katerina, et al.
(author)
-
Characterization of the BRCA1-like immunoreactivity of human seminal plasma
- 1999
-
In: Urology. - 0090-4295. ; 54:4, s. 753-762
-
Journal article (peer-reviewed)abstract
- Objectives. The subcellular localization of the breast cancer susceptibility gene product BRCA1 has been controversial. Discrepant results have been reported during the past 3 years, partially because of the unavailability of highly specific reagents for BRCA1 protein. Our objective was to characterize the BRCA1-like immunoreactivity that is detected in human seminal plasma by using monoclonal and polyclonal antibodies that are supposedly specific for BRCA1 protein. Methods. We used immunologic, chromatographic, and protein sequencing techniques to detect the immunoreactivity of BRCA1 in seminal plasma and to purify and partially identify the immunoreactive species. Results. We present data indicating that two BRCA1 antibodies, SG-11 and D-20, which were thought to be free of cross- reactivities, strongly interact with proteins present in human seminal plasma. This crossreactivity is detectable even at seminal plasma dilutions as high as 106-fold, and it is effectively blocked by peptides that capture the binding site of either SG-11 or D-20 antibodies. Purification and characterization of the immunoreactive compound revealed that this consists of a macromolecular complex that contains semenogelins. The D-20 polyclonal antibody was found to cross-react with purified semenogelins I and II; the SG-11 monoclonal antibody appeared to recognize a component of the macromolecular complex that was not semenogelin. Conclusions. Our data demonstrate that the BRCA1 antibodies SG-11 and D-20 strongly interact with seminal plasma proteins and are not highly specific for BRCA1 protein. It is thus suggested that BRCA1 antibodies should be used with caution until reagents free of interference are developed and evaluated. In light of the very high cross-reactivity of the two antibodies with seminal plasma proteins, we recommend that new BRCA1 antibodies should be examined for cross-reactivity with seminal plasma proteins to verify specificity.
|
|
7. |
- Bratt, O, et al.
(author)
-
Sons of men with prostate cancer : their attitudes regarding possible inheritance of prostate cancer, screening, and genetic testing
- 1997
-
In: Urology. - 0090-4295. ; 50:3, s. 5-360
-
Journal article (peer-reviewed)abstract
- OBJECTIVES: To study attitudes regarding possible inheritance of prostate cancer among sons of men with prostate cancer.METHODS: A questionnaire was sent to 69 men with prostate cancer and their 101 unaffected sons. All participants were also interviewed by telephone. Sociodemographic data were collected, as were data about the fathers' disease.RESULTS: The response rate was high; 100 sons (99%) and 65 fathers (94%) answered all questions. Sixty of the sons claimed they had worries about having an increased risk of prostate cancer due to possible inheritance. About 90% of the sons wanted to know whether prostate cancer was inheritable (66 definitely and 24 probably), were positively inclined to undergo screening (65 definitely and 27 probably), and to undergo genetic testing (50 definitely and 41 probably), provided there had been multiple cases of prostate cancer in their family. An interest to know whether prostate cancer could be inherited was more frequent among sons with less than 12 years of education, worries about inheritance, younger age, a father treated with curative intent, and with children of their own, especially if sons. Interest in genetic testing was associated with less than 12 years of education and with worries about inheritance.CONCLUSIONS: A large majority of healthy men with a family history of prostate cancer were interested in knowing whether the disease could be inherited and were positively inclined to undergo screening and genetic testing. Our findings indicate that genetic counseling and a screening program could have beneficial psychological effects in families with multiple cases of prostate cancer.
|
|
8. |
- Iwamura, Masatsugu, et al.
(author)
-
Alteration of the hormonal bioactivity of parathyroid hormone-related protein (PTHrP) as a result of limited proteolysis by prostate-specific antigen
- 1996
-
In: Urology. - 0090-4295. ; 48:2, s. 317-325
-
Journal article (peer-reviewed)abstract
- Objectives. To discover whether the proteolytic activity of prostate- specific antigen (PSA) affects the structure and function of parathyroid hormone-related protein (PTHrP), as both are abundant components of human seminal plasma. Methods. The ability of PTHrP to act as a substrate was studied by incubating a synthetic polypeptide, consisting of 34 amino acid residues of the amino-terminal domain of PTHrP, with purified PSA. The incubate was then analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, high-pressure liquid chromatography separation, amino- terminal peptide sequencing, and mass spectrometry. The physiologic effect of the proteolytic activity of PSA on PTHrP was studied by measuring any alteration in PTHrP (1-34)-induced elevation of cyclic adenosine monophosphate (cAMP) production by UMR-106 rat osteosarcoma cells in culture. All cell culture experiments were performed with PSA and PTHrP (1-34) at physiologic concentrations. Results. Our data show that PSA proteolytically cleaves PTHrP (1-34) after either residue 22 or 23, generating three peptide fragments. Both cleavages occur carboxy terminally of a phenylalanine residue. The cAMP production in rat osteosarcoma cells, induced by the amino- terminal portion of PTHrP (1-34), as a result of its structural similarity with parathyroid hormone (PTH), was abated by PSA in a dose- and time- dependent fashion. In contrast, heat-inactivated PSA had no effect on cAMP production. Conclusions. Our study demonstrates that PTHrP is a substrate for PSA. The cleavage of the amino-terminal portion of PTHrP completely disrupts its ability to interact with the PTH/PTHrP receptor and thus inhibits its PTH-like activity. The proteolytic processing of PTHrP by PSA may play an important role in the post-translational/post-secretional regulation of prostatic PTHrP activities, which are believed to include regulation of prostate growth and differentiation.
|
|
9. |
- Jacobsen, Steven J., et al.
(author)
-
Stability of serum prostate-specific antigen determination across laboratory, assay, and storage time
- 1995
-
In: Urology. - 0090-4295. ; 45:3, s. 447-453
-
Journal article (peer-reviewed)abstract
- Objectives: To understand the comparability of serum prostate-specific antigen (PSA) determinations across assays and storage time. Methods: Serum PSA levels were determined for men aged 40 to 79 years from the clinical subset of the Olmsted County Study of Urinary Symptoms and Health Status Among Men on fresh samples and after a median of 32 months on banked samples, frozen at -70 °C. Baseline serum PSA levels were determined by Tandem-R PSA assay. Follow-up levels on the banked samples were determined by the IMx PSA assay and a repeat Tandem-R PSA assay in a different laboratory and by an immunofluorometric PSA assay at another site. Results: The median serum PSA level determined by Tandem-R assay at baseline was 1.0 ng/mL (25th percentile, 0.6; 75th percentile, 1.7). The distributions of determination made by follow-up Tandem-R, IMx, and immunofluorometric analyses were essentially identical. Overall, the assays were highly correlated. The correlations between the baseline serum PSA determination and repeated Tandem-R, IMx, and immunofluorometric determinations were 0.96, 0.96, and 0.97, respectively (all P < 0.001). The median duration of frozen storage was 32 months (range, 26 to 39 months), and the correlations between baseline and follow-up determinations did not change when stratified by duration of storage. Conclusions: These data provide important reassurance about the use of serum PSA determinations obtained by different assays, in different laboratories, and in properly tored samples across time.
|
|
10. |
|
|