| 1. |
- Darst, Burcu F., et al.
(författare)
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The Four-Kallikrein Panel Is Effective in Identifying Aggressive Prostate Cancer in a Multiethnic Population
- 2020
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Ingår i: Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology. - 1538-7755. ; 29:7, s. 1381-1388
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The four-kallikrein (4K) panel has been demonstrated to improve prediction of aggressive prostate cancer compared with prostate-specific antigen (PSA) among men with moderately elevated PSA levels. However, the development and testing of the 4K panel has been conducted primarily in White men, with limited data in African Americans and no studies in other racial and ethnic groups. METHODS: We evaluated the 4K panel in a nested case-control study among African American, Latino, Japanese, Native Hawaiian, and White men in the Multiethnic Cohort. Prediagnostic blood levels of free, intact, and total PSA and human kallikrein-related peptidase 2 were measured among 1,667 incident prostate cancer cases and 691 controls with PSA ≥2 ng/mL. We evaluated the discriminative ability of the 4K panel within and across all racial/ethnic groups. RESULTS: The 4K panel enhanced discrimination of overall prostate cancer compared with free plus total PSA and total PSA alone (AUC 0.748 vs. 0.711 and 0.669, respectively). Discrimination was further enhanced for Gleason 8+ prostate cancer, aggressive prostate cancer, and death due to prostate cancer, and to a lesser degree for nonaggressive prostate cancer. Improvement of the 4K panel over PSA was observed in each population. Adding a prostate cancer polygenic risk score slightly improved upon the discriminative ability of the 4K panel. CONCLUSIONS: The superior discriminative ability of the 4K panel over PSA for overall and aggressive prostate cancer across multiethnic populations indicates the broad clinical applicability of the 4K panel. IMPACT: Our multiethnic investigation suggests potential for the 4K panel to improve current prostate cancer screening practices.
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| 2. |
- Lonergan, Peter E., et al.
(författare)
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Prospective validation of microseminoprotein-β added to the 4Kscore in predicting high-grade prostate cancer in an international multicentre cohort
- 2021
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Ingår i: BJU International. - : Wiley. - 1464-4096 .- 1464-410X. ; 128:2, s. 218-224
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To prospectively evaluate the performance of a pre-specified statistical model based on four kallikrein markers in blood (total prostate-specific antigen [PSA], free PSA, intact PSA, and human kallikrein-related peptidase 2), commercially available as the 4Kscore, in predicting Gleason Grade Group (GG) ≥2 prostate cancer at biopsy in an international multicentre study at three academic medical centres, and whether microseminoprotein-β (MSP) adds predictive value. Patients and Methods: A total of 984 men were prospectively enrolled at three academic centres. The primary outcome was GG ≥2 on prostate biopsy. Three pre-specified statistical models were used: a base model including PSA, age, digital rectal examination and prior negative biopsy; a model that added free PSA to the base model; and the 4Kscore. Results: A total of 947 men were included in the final analysis and 273 (29%) had GG ≥2 on prostate biopsy. The base model area under the receiver operating characteristic curve of 0.775 increased to 0.802 with the addition of free PSA, and to 0.824 for the 4Kscore. Adding MSP to the 4Kscore model yielded an increase (0.014–0.019) in discrimination. In decision-curve analysis of clinical utility, the 4Kscore showed a benefit starting at a 7.5% threshold. Conclusion: A prospective multicentre evaluation of a pre-specified model based on four kallikrein markers (4Kscore) with the addition of MSP improves the predictive discrimination for GG ≥2 prostate cancer on biopsy and could be used to inform biopsy decision-making.
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| 3. |
- Sävblom, Charlotta, et al.
(författare)
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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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Ingår i: Clinical Chemistry. - : Oxford University Press (OUP). - 0009-9147 .- 1530-8561. ; 60:3, s. 490-499
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Tidskriftsartikel (refereegranskat)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. (C) 2013 American Association for Clinical Chemistry
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| 4. |
- Vertosick, Emily A., et al.
(författare)
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Individual Patient Data Meta-analysis of Discrimination of the Four Kallikrein Panel Associated With the Inclusion of Prostate Volume
- 2021
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Ingår i: Urology. - : Elsevier BV. - 0090-4295. ; 157, s. 102-106
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To assess whether adding prostate volume to the kallikrein panel improves discrimination for ISUP Grade Group 2 or higher (GG2+) disease, as some men may have volume measurements available at the time of blood draw. While prostate volume predicts biopsy outcome, it requires an imaging procedure for measurement. The four kallikrein panel - commercially available as the 4Kscore - predicts risk of GG2+ disease and requires only a blood draw. Materials and Methods: A total of 9131 patients with available prostate volume and total PSA ≤25 ng/ml from 5 historical (sextant biopsy, pre-ISUP 2005 grading) and 4 contemporary cohorts (10+ cores, ISUP 2005 grading). Previously published kallikrein panel models were used to predict risk of GG2+. Volume was added to the model in each cohort and change in discrimination was meta-analyzed. Results: Increased prostate volume was associated with decreased risk of GG2+ disease after controlling for the kallikrein panel in 7/9 cohorts. However, kallikrein panel discrimination (0.817, 95% CI 0.802, 0.831) was not improved after including volume (AUC difference 0.002, 95% CI -0.003, 0.006). Heterogeneity (P <.0001) was driven by an AUC increase in 1 cohort of academic cancer centers (0.044, 95% CI 0.025, 0.064), with no evidence of heterogeneity after excluding this cohort (P = .15). Conclusion: The kallikrein panel provides a non-invasive approach to assess the risk of high-grade prostate cancer. Our results do not justify the inclusion of prostate volume in the four kallikrein panel. There is some evidence that the predictive value of prostate volume is provider dependent: further research is needed to address this question. © 2021 Elsevier Inc.
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| 5. |
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| 6. |
- Vertosick, Emily A, et al.
(författare)
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Prespecified Four Kallikrein Marker Model (4Kscore) at Age 50 or 60 for Early Detection of Lethal Prostate Cancer in a Large Population-Based Cohort of Asymptomatic Men Followed for 20 Years.
- 2020
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Ingår i: Journal of Urology. - : Lippincott Williams & Wilkins. - 0022-5347 .- 1527-3792. ; 204:2, s. 281-288
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: A prespecified statistical model based on 4 kallikrein markers in blood, commercially available as the 4Kscore®, has been shown to accurately detect high grade (greater than Grade Group 2) prostate cancer in men with moderately elevated prostate specific antigen. We assessed whether the model predicted prostate cancer metastasis or death in men not subject to prostate specific antigen screening.Materials and Methods: The cohort includes 43,692 unscreened prostate cancer-free men from a Swedish population based cohort with low rates of prostate specific antigen screening (Västerbotten Intervention Project). Using cryopreserved blood collected at ages 50 and 60 years from men in this cohort we analyzed the association between prostate specific antigen and other kallikrein marker levels in blood and risk of prostate cancer metastasis or death.Results: There were 308 with metastases and 172 prostate cancer deaths. Baseline prostate specific antigen was strongly associated with 20-year risk of prostate cancer death (c-index at age 50, 0.859, 95% CI 0.799–0.916; age 60, 0.840, 95% CI 0.799–0.878). Men 60 years old with prostate specific antigen below median (less than 1.2 ng/ml) had 0.4% risk of prostate cancer death at 20 years. Among men with moderately elevated prostate specific antigen (2.0 ng/ml or greater) the 4Kscore markedly improved discrimination (c-index 0.767 vs 0.828 and 0.774 vs 0.862 in men age 50 and 60, respectively). Long-term risk of prostate cancer death or metastasis in men with low 4Kscores was very low.Conclusions: Screening should focus on men in top prostate specific antigen quartile at age 60 years. Men with elevated prostate specific antigen but a low 4Kscore can safely be monitored with repeated blood markers in place of immediate biopsy.
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| 7. |
- Vertosick, Emily A., et al.
(författare)
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Reply by Authors
- 2020
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Ingår i: The Journal of urology. - 1527-3792. ; 204:2, s. 287-288
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Tidskriftsartikel (refereegranskat)
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| 8. |
- Vickers, Andrew, et al.
(författare)
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Properties of the 4-Kallikrein Panel Outside the Diagnostic Gray Zone : Meta-Analysis of Patients with Positive Digital Rectal Examination or Prostate Specific Antigen 10 ng/ml and Above
- 2017
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Ingår i: Journal of Urology. - : Ovid Technologies (Wolters Kluwer Health). - 0022-5347 .- 1527-3792. ; 197, s. 607-613
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The 4-kallikrein panel, commercially available as the 4Kscore™, is a reflex test for prostate cancer early detection that has been extensively validated in multiple international cohorts. It has been suggested that use of such reflex tests be limited to those with prostate specific antigen less than 10 ng/ml and negative digital rectal examination. We aimed to determine the value of the panel in men outside this "diagnostic gray zone.". Materials and Methods: We performed an individual patient data meta-analysis using data from prior studies on the 4-kallikrein panel. We calculated the properties of the panel for predicting high grade (Gleason 7+) cancer in a subgroup of men with either positive digital rectal examination or prostate specific antigen 10 to 25 ng/ml. Results: A total 2,891 men from 8 cohorts were included. An important proportion of patients, including 32% in the United States validation study, had prostate specific antigen 10 to 25 ng/ml or a positive digital rectal examination. For men with prostate specific antigen 10 to 25 ng/ml the fixed-effects estimate for the discrimination of the kallikrein model was 0.84 vs 0.69 for the base model (difference 0.128, 95% CI 0.098-0.159). In the positive digital rectal examination group discrimination was 0.82 vs 0.72 (difference 0.092, 95% CI 0.069-0.115). Decision analysis showed a clinical net benefit for use of the panel in this subgroup with a reduction in biopsy rates of about 20% and only a small number of high grade cancers missed, fewer than 3% of those not biopsied. Conclusion: The use of the kallikrein panel in men with a positive digital rectal examination or prostate specific antigen 10 to 25 ng/ml is justified.
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| 9. |
- Vickers, Andrew, et al.
(författare)
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Value of Intact Prostate Specific Antigen and Human Kallikrein 2 in the 4 Kallikrein Predictive Model : An Individual Patient Data Meta-Analysis
- 2018
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Ingår i: Journal of Urology. - : Ovid Technologies (Wolters Kluwer Health). - 0022-5347 .- 1527-3792. ; 199:6, s. 1470-1474
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The 4 kallikrein panel, commercially available as the 4Kscore®, is a statistical model that has been shown to accurately predict Gleason Grade Group 2 or greater (high grade) cancer on biopsy and the long-term risk of distant prostate cancer metastases. The panel includes 2 novel markers, namely intact prostate specific antigen and hK2. It has been questioned whether these 2 additional markers add discrimination to the clinical predictors of patient age, digital rectal examination and prior biopsy, and the established molecular markers total and free prostate specific antigen. Materials and Methods: We performed an individual patient data meta-analysis of published studies in which the 4 kallikrein panel was measured in men undergoing prostate biopsy. We assess the improvement in discrimination associated with including intact prostate specific antigen and hK2 along with total and free prostate specific antigen in the statistical model. Results: Included in analysis were 14,510 men from a total of 10 studies. The fixed effects meta-analytical estimate of the discrimination of the model without intact prostate specific antigen and hK2 was 0.742 (95% CI 0.727–0.756) compared to 0.813 (95% CI 0.801–0.825) for the full kallikrein model. The 95% CIs did not overlap and the difference in discrimination was highly statistically significant (0.069, 95% CI 0.057–0.080, p <0.0001). Intact prostate specific antigen (increase in discrimination 0.059, 95% CI 0.050–0.069) and hK2 (increase in discrimination 0.024, 95% CI 0.020–0.029, each p <0.0001) added independently to the model. Conclusions: The clinical value of the panel could not be replicated using data readily available to urologists without measuring intact prostate specific antigen and hK2.
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