| 1. |
- Sävblom, Charlotta, et al.
(author)
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Genetic variation in KLK2 and KLK3 is associated with concentrations of hK2 and PSA in serum and seminal plasma in young men
- 2014
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In: Clinical Chemistry. - : American Association for Clinical Chemistry. - 0009-9147 .- 1530-8561. ; 60:3, s. 490-499
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Journal article (peer-reviewed)abstract
- BACKGROUND: Genetic variants in KLK2 and KLK3 have been associated with increased serum concentrations of their encoded proteins, human kallikrein-related peptidase 2 (hK2) and prostate-specific antigen (PSA), and with prostate cancer in older men. Low PSA concentrations in seminal plasma (SP) have been associated with low sperm motility. To evaluate whether KLK2 and KLK3 genetic variants affect physiological prostatic secretion, we studied the association of SNPs with hK2 and PSA concentrations in SP and serum of young, healthy men.METHODS: Leukocyte DNA was extracted from 303 male military conscripts (median age 18.1 years). Nine SNPs across KLK2-KLK3 were genotyped. We measured PSA and hK2 in SP and serum using immunofluorometric assays. The association of genotype frequencies with hK2 and PSA concentrations was tested with the Kruskal-Wallis test.RESULTS: Four KLK2 SNPs (rs198972, rs198977, rs198978, and rs80050017) were strongly associated with hK2 concentrations in SP and serum, with individuals homozygous for the major alleles having 3- to 7-fold higher concentrations than the intermediate concentrations found in other homozygotes and heterozygotes (all P < 0.001). Three of these SNPs were significantly associated with percentage of free PSA (%fPSA) in serum (all P < 0.007). Three KLK3 SNPs showed associations with PSA in SP, and the rs1058205 SNP was associated with total PSA in serum (P = 0.001) and %fPSA (P = 0.015).CONCLUSIONS: Associations observed in young, healthy men between the SP and serum concentrations of hK2 and PSA and several genetic variants in KLK2 and KLK3 could be useful to refine models of PSA cutoff values in prostate cancer testing.
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| 2. |
- Christensson, Anders, et al.
(author)
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Association of cancer with moderately impaired renal function at baseline in a large, representative, population-based cohort followed for up to 30 years.
- 2013
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In: International Journal of Cancer. - : Wiley. - 0020-7136. ; 133:6, s. 1452-1458
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Journal article (peer-reviewed)abstract
- Patients with chronic renal failure show a greater incidence of malignancies. We evaluated whether moderately impaired renal function at baseline influenced risk of all cancers during long-term follow in young persons. Our cohort included 33,346 subjects, aged 26-61 years at baseline, in a representative, population-based study enrolling subjects from 1974 to 1992. Median follow-up time was 28 years. Plasma creatinine was analysed as a single measure at baseline. Incident cases of cancer were identified from the Swedish Cancer Registry. We studied 24,552 subjects from the cohort. To account for the unique sampling design, participants were divided by sex and age at baseline into 1,132 older men (age 60), 14,254 younger men (age 40-52), 7,498 older women (age 47-57) and 1,688 younger women (age 35-43). Glomerular filtration rate (GFR) was estimated using the CKD-EPI formula. Patients were classified as having either normal to mildly impaired kidney function (eGFR≥60 mL/min/1.73m(2) ), or moderate kidney dysfunction (eGFR<60 mL/min/1.73m(2) ). We calculated the risk of all cancers using competing risks regression. Overall, 6,595 participants were diagnosed with cancer, and 854 subjects (3.5%) had moderately impaired renal dysfunction at baseline. There was a significant association between moderately decreased GFR and subsequent risk of kidney cancer in younger men (hazard ratio, 3.38; 95% CI, 1.48 to 7.71; P=0.004). However, we found no association with overall long-term cancer risk. Our confirmation of an association between moderately impaired renal function and risk of kidney cancer in younger men requires further exploration of high-risk groups and biological mechanisms. © 2013 Wiley Periodicals, Inc.
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| 3. |
- Gallagher, David J., et al.
(author)
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Susceptibility Loci Associated with Prostate Cancer Progression and Mortality
- 2010
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In: Clinical Cancer Research. - 1078-0432. ; 16:10, s. 2819-2832
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Journal article (peer-reviewed)abstract
- Purpose: Prostate cancer is a heterogenous disease with a variable natural history that is not accurately predicted by currently used prognostic tools. Experimental Design: We genotyped 798 prostate cancer cases of Ashkenazi Jewish ancestry treated for localized prostate cancer between June 1988 and December 2007. Blood samples were prospectively collected and de-identified before being genotyped and matched to clinical data. The survival analysis was adjusted for Gleason score and prostate-specific antigen. We investigated associations between 29 single nucleotide polymorphisms (SNP) and biochemical recurrence, castration-resistant metastasis, and prostate cancer-specific survival. Subsequently, we did an independent analysis using a high-resolution panel of 13 SNPs. Results: On univariate analysis, two SNPs were associated (P < 0.05) with biochemical recurrence, three SNPs were associated with clinical metastases, and one SNP was associated with prostate cancer specific mortality. Applying a Bonferroni correction (P < 0.0017), one association with biochemical recurrence (P = 0.0007) was significant. Three SNPs showed associations on multivariable analysis, although not after correcting for multiple testing. The secondary analysis identified an additional association with prostate cancer-specific mortality in KLK3 (P < 0.0005 by both univariate and multivariable analysis). Conclusions: We identified associations between prostate cancer susceptibility SNPs and clinical end points. The rs61752561 in KLK3 and rs2735839 in the KLK2-KLK3 intergenic region were strongly associated with prostate cancer-specific survival, and rs10486567 in the 7JAZF1 gene were associated with biochemical recurrence. A larger study will be required to independently validate these findings and determine the role of these SNPs in prognostic models. Clin Cancer Res; 16(10); 2819-32. (C) 2010 AACR.
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| 4. |
- Vickers, Andrew J., et al.
(author)
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Prostate specific antigen concentration at age 60 and death or metastasis from prostate cancer : Case-control study
- 2010
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In: BMJ (Online). - : BMJ. - 1756-1833 .- 0959-8138 .- 1468-5833. ; 341:7773
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Journal article (peer-reviewed)abstract
- Objective: To determine the relation between concentrations of prostate specific antigen at age 60 and subsequent diagnosis of clinically relevant prostate cancer in an unscreened population to evaluate whether screening for prostate cancer and chemoprevention could be stratified by risk. Design: Case-control study with 1:3 matching nested within a highly representative population based cohort study. Setting: General population of Sweden taking part in the Malmo Preventive Project. Cancer registry at the National Board of Health and Welfare. Participants: 1167 men aged 60 who provided blood samples in 1981 and were followed up to age 85. Main outcome measures: Metastasis or death from prostate cancer. Results: The rate of screening during the course of the study was low. There were 43 cases of metastasis and 35 deaths from prostate cancer. Concentration of prostate specific antigen at age 60 was associated with prostate cancer metastasis (area under the curve 0.86, 95% confidence interval 0.79 to 0.92; P<0.001) and death from prostate cancer (0.90, 0.84 to 0.96; P<0.001). The greater the number for the area under the curve (values from 0 to 1) the better the test. Although only a minority of the men with concentrations in the top quarter (>2 ng/ml) develop fatal prostate cancer, 90% (78% to 100%) of deaths from prostate cancer occurred in these men. Conversely, men aged 60 with concentrations at the median or lower (≤1 ng/ml) were unlikely to have clinically relevant prostate cancer (0.5% risk of metastasis by age 85 and 0.2% risk of death from prostate cancer). Conclusions: The concentration of prostate specific antigen at age 60 predicts lifetime risk of metastasis and death from prostate cancer. Though men aged 60 with concentrations below the median (≤1 ng/ml) might harbour prostate cancer, it is unlikely to become life threatening. Such men could be exempted from further screening, which should instead focus on men with higher concentrations.
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| 5. |
- Vickers, Andrew J, et al.
(author)
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Prostate specific antigen velocity does not aid prostate cancer detection in men with prior negative biopsy.
- 2010
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In: The Journal of urology. - : Ovid Technologies (Wolters Kluwer Health). - 1527-3792 .- 0022-5347. ; 184:3, s. 907-12
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Journal article (peer-reviewed)abstract
- Prostate specific antigen velocity has been proposed as a marker to aid in prostate cancer detection. We determined whether prostate specific antigen velocity could predict repeat biopsy results in men with persistently increased prostate specific antigen after initial negative biopsy.
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| 6. |
- Vickers, Andrew J., et al.
(author)
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Prostate-Specific Antigen Velocity for Early Detection of Prostate Cancer: Result from a Large, Representative, Population-based Cohort
- 2009
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In: European Urology. - : Elsevier BV. - 1873-7560 .- 0302-2838. ; 56:5, s. 753-760
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Journal article (peer-reviewed)abstract
- Background: It has been suggested that changes in prostate-specific antigen (PSA) over time (ie, PSA velocity [PSAV]) aid prostate cancer detection. Some guidelines do incorporate PSAV cut points as an indication for biopsy. Objective: To evaluate whether PSAV enhances prediction of biopsy outcome in a large, representative, population-based cohort. Design, setting, and participants: There were 2742 screening-arm participants with PSA < 3 ng/ml at initial screening in the European Randomized Study of Screening for Prostate Cancer in Rotterdam, Netherlands, or Goteborg, Sweden, and who were subsequently biopsied during rounds 2-6 due to elevated PSA. Measurements: Total, free, and intact PSA and human kallikrein 2 were measured for 16 screening rounds at intervals of 2 or 4 yr. We created logistic regression models to predict prostate cancer based on age and PSA, with or without free-to-total PSA ratio (%fPSA). PSAV was added to each model and any enhancement in predictive accuracy assessed by area under the curve (AUC). Results and limitations: PSAV led to small enhancements in predictive accuracy (AUC of 0.569 vs 0.531; 0.626 vs 0.609 if %fPSA was included), although not for high-grade disease. The enhancement depended on modeling a nonlinear relationship between PSAV and cancer. There was no benefit if we excluded men with higher velocities, which were associated with lower risk. These results apply to men in a screening program with elevated PSA; men with prior negative biopsy were not evaluated in this study. Conclusions: In men with PSA of about >= 3 ng/ml, we found little justification for formal calculation of PSAV or for use of PSAV cut points to determine biopsy. Informal assessment of PSAV will likely aid clinical judgment, such as a sudden rise in PSA suggesting prostatitis, which could be further evaluated before biopsy. (C) 2009 European Association of Urology. Published by Elsevier B. V. All rights reserved.
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| 7. |
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| 8. |
- Bruun, Laila, et al.
(author)
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Increase in percent free prostate-specific antigen in men with chronic kidney disease.
- 2009
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In: Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association. - : Oxford University Press (OUP). - 1460-2385. ; 24:4, s. 1238-41
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Journal article (peer-reviewed)abstract
- BACKGROUND: Prostate-specific antigen (PSA) occurs in different molecular forms in serum: free PSA (fPSA) and complexed PSA (cPSA), the sum of which corresponds to total PSA (tPSA). In addition to tPSA, percent fPSA is widely used in the detection of prostate cancer. Free PSA, approximately 28 kDa, is eliminated by glomerular filtration. Previous data showed that men with end-stage renal dysfunction requiring chronic dialysis have increased percent fPSA. In this study, we evaluated whether moderate-to-severe chronic renal dysfunction, but with no need for dialysis, also importantly affects percent fPSA. METHODS: The study group consisted of 101 men (median age 57 years, interquartile range 46-68) with chronic kidney disease and no diagnosis of prostate cancer. Their median glomerular filtration rate (GFR) was 23 mL/min/1.73 m(2) (interquartile range 16-33; range 8-83), determined by iohexol clearance. Controls included 5264 men (median age 57 years, interquartile range 54-62) attending a prostate cancer screening program with no diagnosis of prostate cancer during 8 years of follow-up. RESULTS: With adjustment for age, median fPSA levels and percent fPSA were significantly higher (P < 0.001) in patients with renal dysfunction, 0.45 microg/L and 47.2%, respectively, compared to controls, 0.29 microg/L and 29.9%, respectively. Regression analysis in the study group showed a significant association between GFR and percent fPSA (P = 0.036). CONCLUSIONS: The percent fPSA is importantly influenced by moderately impaired renal function in men with chronic kidney disease. For such men, use of the current clinical decision limits for percent fPSA could cause some men with prostate cancer to be misdiagnosed as having benign disease, and therefore fPSA should not be used to diagnose prostate cancer in these patients.
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| 9. |
- Christensson, Anders, et al.
(author)
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Intra-individual short-term variability of prostate-specific antigen and other kallikrein markers in a serial collection of blood from men under evaluation for prostate cancer.
- 2011
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In: BJU International. - 1464-4096. ; 107, s. 1769-1774
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Journal article (peer-reviewed)abstract
- Study Type - Diagnostic (exploratory cohort) Level of Evidence 2b OBJECTIVES: To assess variation of total prostate-specific antigen (tPSA), free PSA (fPSA), percent fPSA, human glandular kallikrein 2 (hK2) and intact PSA measured three times within 2 weeks. Knowledge of the variation in an individual's PSA level is important for clinical decision-making. PATIENTS AND METHODS: Study participants were 149 patients referred for prostate biopsy, of which 97 had benign disease and 52 had prostate cancer. Three blood samples were drawn with a median of 4 h between first and second samples and 12 days between first and third samples. Variability was described by absolute differences, ratios and intra-individual coefficients of variation. Total PSA, fPSA, hK2 and intact PSA were measured in anticoagulated blood plasma. RESULTS: At baseline, the median tPSA was 6.8 (interquartile range, 4.5-9.6) ng/mL. The intra-individual variation was low for all biomarkers, and lowest for tPSA. For 80% of participants, the ratio between first and second time points for tPSA was in the range 0.91-1.09 and the ratio for percent fPSA was in the range 0.89-1.15. Total coefficients of variation between time 1 and 2 for tPSA, fPSA, percent fPSA, hK2 and intact PSA were 4.0%, 6.6%, 6.0%, 9.2% and 9.5%, respectively. The measurements taken several days apart varied more than those taken on the same day, although the variation between both time points was not large. CONCLUSIONS: The intra-individual variation for all the kallikrein-like markers studied was relatively small, especially for samples drawn the same day. Few cases are reclassified between the time points. This indicates the high short-term biological and technical reproducibility of the tests in clinical use.
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| 10. |
- Klein, Robert J, et al.
(author)
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Blood biomarker levels to aid discovery of cancer-related single-nucleotide polymorphisms : kallikreins and prostate cancer
- 2010
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In: Cancer Prevention Research. - : American Association for Cancer Research. - 1940-6207 .- 1940-6215. ; 3:5, s. 611-619
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Journal article (peer-reviewed)abstract
- Polymorphisms associated with prostate cancer include those in three genes encoding major secretory products of the prostate: KLK2 (encoding kallikrein-related peptidase 2; hK2), KLK3 (encoding prostate-specific antigen; PSA), and MSMB (encoding beta-microseminoprotein). PSA and hK2, members of the kallikrein family, are elevated in sera of men with prostate cancer. In a comprehensive analysis that included sequencing of all coding, flanking, and 2 kb of putative promoter regions of all 15 kallikrein (KLK) genes spanning approximately 280 kb on chromosome 19q, we identified novel single-nucleotide polymorphisms (SNP) and genotyped 104 SNPs in 1,419 cancer cases and 736 controls in Cancer Prostate in Sweden 1, with independent replication in 1,267 cases and 901 controls in Cancer Prostate in Sweden 2. This verified prior associations of SNPs in KLK2 and in MSMB (but not in KLK3) with prostate cancer. Twelve SNPs in KLK2 and KLK3 were associated with levels of PSA forms or hK2 in plasma of control subjects. Based on our comprehensive approach, this is likely to represent all common KLK variants associated with these phenotypes. A T allele at rs198977 in KLK2 was associated with increased cancer risk and a striking decrease of hK2 levels in blood. We also found a strong interaction between rs198977 genotype and hK2 levels in blood in predicting cancer risk. Based on this strong association, we developed a model for predicting prostate cancer risk from standard biomarkers, rs198977 genotype, and rs198977 x hK2 interaction; this model had greater accuracy than did biomarkers alone (area under the receiver operating characteristic curve, 0.874 versus 0.866), providing proof in principle to clinical application for our findings.
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