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- Haese, A, et al.
(author)
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The role of human glandular kallikrein 2 for prediction of pathologically organ confined prostate cancer
- 2003
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In: The Prostate. - : Wiley. - 0270-4137 .- 1097-0045. ; 54:3, s. 181-186
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Journal article (peer-reviewed)abstract
- BACKGROUND. In recent studies serum levels of human glandular kallikrein 2 (hK2) demonstrated significant differences in pathologically organ-confined versus non-organ-confined prostate cancer (Pca). In this study we investigated whether hK2 adds independent information when considered together with traditionally used parameters to predict organ confined (pT2a/b) PCa. METHODS. Serum levels of hK2, total and free prostate-specific antigens (PSA) were obtained one day before radical prostatectomy in 245 consecutive men. These were included with clinical stage and biopsy Gleason grade into univariate analysis and multivariate logistic regression models. RESULTS. pT2a/b PCa was found in n = 148 patients. In univariate analysis all preoperative parameters demonstrated significant association with the presence of pT2a/b PCa. Using multivariate logistic regression model hK2 (P = 0.022), clinical stage (P < 0.0001), and Gleason grade (P < 0.0001) were independent predictors of pT2a/b PCa whereas PSA (P = 0.3) was not. In bootstrap corrected logistic regression based nomograms the addition of hK2 density marginally enhanced predictive accuracy when PSA, PSA density, clinical stage, and Gleason grade were considered (AUC = 0.879 without hK2 density and 0.883 with hK2 density). CONCLUSIONS. hK2 and hK2 density could independently predict pT2a/b PCa. However, improvement in predictive accuracy was marginal when nomograms based on traditional variables were complemented with this serum marker. (C) 2002 Wiley-Liss, Inc.
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| 2. |
- Steuber, T, et al.
(author)
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Risk assessment for biochemical recurrence prior to radical prostatectomy: significant enhancement contributed by human glandular kallikrein 2 (hk2) and free prostate specific antigen (PSA) in men with moderate PSA-elevation in serum
- 2006
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In: International Journal of Cancer. - : Wiley. - 0020-7136. ; 118:5, s. 1234-1240
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Journal article (peer-reviewed)abstract
- Most models to predict biochemical recurrence (BCR) of prostate cancer use pretreatment serum prostate-specific antigen (PSA), clinical stage and prostate biopsy Gleason grade. We investigated whether human glandular kallikrein 2 (hK2) and free prostate-specific antigen (fPSA) measured in pretreatment serum enhance prediction. We retrospectively measured total PSA (tPSA), fPSA and hK2 in preoperative serum samples from 461 men with localized prostate cancer treated with radical prostatectomy between 1999 and 2001. We developed a regression model to predict BCR using preoperative tPSA, clinical stage and biopsy Gleason grade. We then compared the predictive accuracy of this "base" model with a model with fPSA and hK2 as additional predictors. BCR was observed in 90 patients (20%), including 48 patients with a pretreatment tPSA <= 14 ng/ml (13%), and 28 patients (10%) With a pretreatment tPSA <= 10 ng/ml. Overall, the predictive accuracy of the base model (bootstrap-corrected concordance index of 0.813) was not improved after the addition of fPSA or hK2 (0.818). However, for men with moderate tPSA-elevation (tPSA <= 10 ng/ml), addition of fPSA and hK2 data increased predictive accuracy (from a base model concordance index of 0.756-0.815, p = 0.005). The improvement in accuracy was not sensitive to the threshold for "moderately elevated" PSA. For patients with a moderate tPSA-elevation (tPSA <= 10 ng/ml), which closely corresponds to concurrent disease demographics, BCR-prediction was enhanced when fPSA and hK2 were added to the conventional model. Measurements of fPSA and hK2 improve on our ability to counsel patients prior to treatment as to their risk of BCR. (c) 2005 Wiley-Liss, Inc.
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| 3. |
- Vickers, AJ, et al.
(author)
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A panel of kallikrein markers can reduce unnecessary biopsy for prostate cancer: data from the European Randomized Study of Prostate Cancer Screening in Göteborg, Sweden.
- 2008
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In: BMC Medicine. - : Springer Science and Business Media LLC. - 1741-7015. ; 8:6
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Journal article (peer-reviewed)abstract
- Background Prostate-specific antigen (PSA) is widely used to detect prostate cancer. The low positive predictive value of elevated PSA results in large numbers of unnecessary prostate biopsies. We set out to determine whether a multivariable model including four kallikrein forms (total, free, and intact PSA, and human kallikrein 2 (hK2)) could predict prostate biopsy outcome in previously unscreened men with elevated total PSA. Methods The study cohort comprised 740 men in Göteborg, Sweden, undergoing biopsy during the first round of the European Randomized study of Screening for Prostate Cancer. We calculated the area-under-the-curve (AUC) for predicting prostate cancer at biopsy. AUCs for a model including age and PSA (the 'laboratory' model) and age, PSA and digital rectal exam (the 'clinical' model) were compared with those for models that also included additional kallikreins. Results Addition of free and intact PSA and hK2 improved AUC from 0.68 to 0.83 and from 0.72 to 0.84, for the laboratory and clinical models respectively. Using a 20% risk of prostate cancer as the threshold for biopsy would have reduced the number of biopsies by 424 (57%) and missed only 31 out of 152 low-grade and 3 out of 40 high-grade cancers. Conclusion Multiple kallikrein forms measured in blood can predict the result of biopsy in previously unscreened men with elevated PSA. A multivariable model can determine which men should be advised to undergo biopsy and which might be advised to continue screening, but defer biopsy until there was stronger evidence of malignancy.
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