Role of the 4Kscore test as a predictor of reclassification in prostate cancer active surveillance.

BACKGROUND: Management of active surveillance (AS) in low-risk prostate cancer (PCa) patients could be improved with new biomarkers, such as the 4Kscore test. We analyze its ability to predict tumor reclassification by upgrading at the confirmatory biopsy at 6 months. METHODS: Observational, prospective, blinded, and non-randomized study, within the Spanish National Registry on AS (AEU/PIEM/2014/0001; NCT02865330) with 181 patients included after initial Bx and inclusion criteria: PSA ≤10 ng/mL, cT1c-T2a, Grade group 1, ≤2 cores, and ≤5 mm/50% length core involved. Central pathological review of initial and confirmatory Bx was performed on all biopsy specimens. Plasma was collected 6 months after initial Bx and just before confirmatory Bx to determine 4Kscore result. In order to predict reclassification defined as Grade group ≥2, we analyzed 4Kscore, percent free to total (%f/t) PSA ratio, prostate volume, PSA density, family history, body mass index, initial Bx, total cores, initial Bx positive cores, initial Bx % of positive cores, initial Bx maximum cancer core length and initial Bx cancer % involvement. Wilcoxon rank-sum test, non-parametric trend test or Fisher's exact test, as appropriate established differences between groups of reclassification. RESULTS: A total of 137 patients met inclusion criteria. Eighteen patients (13.1%) were reclassified at confirmatory Bx. The %f/t PSA ratio and 4Kscore showed differences between the groups of reclassification (Yes/No). Using 7.5% as cutoff for the 4Kscore, we found a sensitivity of 89% and a specificity of 29%, with no reclassifications to Grade group 3 for patients with 4Kscore below 7.5% and 2 (6%) missed Grade group 2 reclassified patients. Using this threshold value there is a biopsy reduction of 27%. Additionally, 4Kscore was also associated with changes in tumor volume. CONCLUSIONS: Our preliminary findings suggest that the 4Kscore may be a useful tool in the decision-making process to perform a confirmatory Bx in active surveillance management.

The 4Kscore blood test accurately identifies men with aggressive prostate cancer prior to prostate biopsy with or without DRE information.

INTRODUCTION: The 4Kscore Test is a prebiopsy blood test that incorporates four prostate protein biomarkers along with patient clinical information to determine a man's risk for high-grade, aggressive (Gleason ≥7) prostate cancer. However, some men likely to benefit from the test may be seen in primary care settings where the digital rectal examination (DRE) information is not always obtained. In this study, we assessed the clinical validity of the 4Kscore Test when the DRE information was not included in the algorithm. METHODS: The Prospective 4Kscore Validation Study enrolled 1012 men scheduled for prostate biopsy across 26 urology practices in the United States. The 4Kscore was calculated for each patient with and without DRE information. The primary outcome was Gleason ≥7 prostate cancer on prostate biopsy. The contribution of DRE to the predictive accuracy of the test was evaluated by area under the receiver operating curve (AUC-ROC), risk calibration and clinical consequences. RESULTS: High-grade, aggressive prostate cancer was found in 231 (23%) of the 1012 patients. Both versions of the 4Kscore Test, with and without DRE, showed excellent discrimination (AUC=0.821 with DRE and AUC=0.818 without DRE input) and excellent calibration. No clinically significant difference was found between the two versions of the 4Kscore. CONCLUSIONS: The 4Kscore Test algorithm, whether DRE findings are available or not, performs well in predicting a man's risk of high-grade, aggressive prostate cancer. Patients who are suspected of having aggressive prostate cancer can safely have their risk better defined by 4Kscore even if a DRE has not been performed recently.

Clinical performance of the 4Kscore Test to predict high-grade prostate cancer at biopsy: A meta-analysis of us and European clinical validation study results.

The 4Kscore® Test (OPKO Diagnostics, Woburn, MA) is a blood test utilized prior to a prostate biopsy to determine a patient's risk of high-grade prostate cancer (PCa) should the biopsy be performed, thus providing critical information in the clinical management of men with a suspicious prostate-specific antigen value or digital rectal examination result. Multiple US and European clinical studies confirmed that a prebiopsy 4Kscore Test has a high degree of discrimination for a subsequent discovery of high-grade (Gleason score ≥7) PCa. The aim of this study was to evaluate the predictive accuracy of the 4Kscore Test to discriminate between patients with and without high-grade PCa based on published clinical validation studies. A systematic review and meta-analysis of the eligible 4Kscore Test clinical validation studies was conducted. The pooled area under the curve (AUC) of the 4Kscore Test as reported from all the studies, and the heterogeneity among these studies were analyzed and repeated for subgroups of the studies. Twelve clinical validation studies were included in the meta-analysis, comprising a total of 11,134 patients. The pooled AUC to discriminate for high-grade PCa for all 12 studies was 0.81 (fixed effects 95% CI, 0.80-0.83). Restricting the analysis to the six publications that used the contemporary 4Kscore Test algorithm led to very similar results (AUC 0.81; 95% CI, 0.79-0.83). Heterogeneity was high among all of the 12 studies, as well as among the six publications that used the contemporary 4Kscore Test (Cochrane's Q test, p = 0.001 for both); however, in both cases, after exclusion of a single outlying study with a much lower AUC, heterogeneity was no longer significant (p = 0.08 and p = 0.21). The pooled estimate of 4Kscore Test discrimination (AUC) for high-grade PCa is >0.80, and is consistent across multiple US and European clinical validation studies.

Comparison of two methods to assess variability of platelet response to anti-platelet therapies in patients with acute coronary syndrome undergoing angioplasty.

The study investigated the clinical usefulness of a new method to evaluate platelet activation and the variability of platelet response to anti-platelet therapy in patients undergoing percutaneous transluminal coronary angioplasty (PTCA). Platelet activation was assessed in parallel by a new method for platelet density measurements (MPC, Mean Platelet Component Concentration), on the automated ADVIA 120 Hematology System and by the classic measurement of P-selectin (CD62P) expression, on a fluorescence flow cytometer. Patients received a loading dose of clopidogrel (300 mg; n = 29) or a bolus of abciximab (0.25 mg/kg; n = 15). Blood samples were collected before (baseline) and at different times after PTCA and antiplatelet drugs administration. Our data showed a close inverse correlation between the change in MPC and the CD62P fluorescence surface marker expression (r = -0.776, P<0.0001). Individual platelet activation determinations in patients receiving either clopidogrel or abciximab showed a variation in platelet activation as assayed by MPC and CD62P expression. Patients were characterized as having either high platelet activity upon admission and positive response to treatment or no detectable platelet activation before or after treatment. This study demonstrates the heterogeneity of platelet activation states in ACS patients undergoing coronary angioplasty. The present work also illustrates the potential use of the MPC parameter, generated on an automated hematology system, to define high risk patients and to monitor the variability of platelet response to anti-platelet therapies.

The ADVIA Centaur immunoassay system--designed for infectious disease testing.

The ability to automate immunodiagnostics testing is critical for the efficiency of clinical laboratories. For automation of Infectious Disease testing, special design considerations must be made to ensure the integrity of the testing result while at the same time delivering productivity. The ADVIA Centaur was designed with the intent of performing a complete Infectious Disease panel including HBV, HCV, and HIV markers. Features such as disposable sample tips, sample and reagent delivery verification, and clog and clog detection have been incorporated in the design for assay robustness. Productivity features deliver best in class throughput performance for the Infectious Disease assays. Moreover, the underlying technology incorporating flexible assay protocols, universal solid phases and proprietary acridinium ester technology contribute to the assay design flexibility and analytical performance of the ADVIA Centaur immunoassay system.

Assessment of platelet activation in several different anticoagulants by the Advia 120 Hematology System, fluorescence flow cytometry, and electron microscopy.

In vivo platelet activation results are often confounded by activation induced in vitro during the preparative procedures. We measured ex vivo (basal) and in vitro (thrombin-induced) platelet activation in sodium citrate, ethylenediaminetetraacetic acid (EDTA), and Citrate Theophylline Dipyridamole Adenosine (CTAD) whole blood specimens. Determinations were made by measurements of platelet density (mean platelet component: MPC concentration) on the Advia 120 Hematology System. The MPC has been previously shown to correlate with a fluorescence flow cytometric method, also determined in this study, using the surface expression of CD62P. Moreover, platelet shape and structure changes in EDTA and CTAD anticoagulated whole blood specimens were characterized by transmission electron microscopy (TEM). Observations made using the Advia 120 Hematology System platelet density parameter, MPC, in the absence of thrombin were 25.7 +/- 0.9 g/dl, 27.9 +/- 0.9 g/dl and 24.8 +/- 1.2 g/dl in sodium citrate, EDTA and CTAD whole blood specimens, respectively. Addition of thrombin induced a significant change in platelet MPC for sodium citrate (21.9 +/- 1.9 g/dl; p<0.0001) and EDTA (23.2 +/- 0.9 g/dl; p<0.0001) whole blood specimens. In contrast, thrombin had no effect on MPC measured in whole blood taken into CTAD tubes. In vitro fluorescence flow cytometric platelet activation experiments measuring the percentage of platelets expressing anti-CD62P showed increase in sodium citrate specimens from 9.2 +/- 7.0 to 55.5 +/- 23.1 % (p<0.0001) and in EDTA specimens from 1.9 +/- 1.7 to 64.6 +/- 12.4 % (p<0.0001) after addition of thrombin. However, in blood taken into CTAD tubes, there was no significant change. Studies on platelets isolated from whole blood in CTAD showed activation by thrombin indicating that platelets in CTAD, while protected in its presence remained functional upon its removal. When observed by TEM over time, platelets in EDTA appear more activated and contain fewer granules than platelets in CTAD. We conclude that CTAD demonstrates in vitro platelet activation inhibition and may be useful in stabilizing ex vivo platelet activation. The novel platelet activation parameter, MPC, measured by an automated routine hematology system, using customized proprietary software, may be used in conjunction with CTAD, a stabilizing anticoagulant, to measure the ex vivo platelet activation state in whole blood specimens. TEM studies verify shape modifications and simultaneous retention of intracellular granules at early post-venipuncture time periods in CTAD specimens.

A rapid, automated flow cytometric method to measure activated degranulated platelets by density determination.

Platelet activation is reported to correlate with acute coronary syndromes. A platelet analysis method on the ADVIA 120 Hematology System provides rapid analysis of platelet density, reported as mean platelet component (MPC) concentration, utilizes routine hematology specimens, requires no pre-treatment, and thirty seconds to generate results. Sub-populations of platelets separated by density gradients showed excellent correlation with the ADVIA 120 MPC parameter (r = 0.997). Platelet activation induced by thrombin treatment resulted in a shift of platelets into the lowest density fraction (d

Evaluation of the anticoagulants EDTA and citrate, theophylline, adenosine, and dipyridamole (CTAD) for assessing platelet activation on the ADVIA 120 hematology system.

BACKGROUND: Monitoring of platelet activation by the ADVIA 120 Hematology System requires an anticoagulant and protocol that ensures that platelets are sphered and their activation status is not altered artifactually in vitro. METHODS: Blood from healthy controls was collected into tripotassium EDTA; citrate, theophylline, adenosine, and dipyridamole (CTAD); or a combination of both (E/C) and stored at ambient temperature or at 4 degrees C (E/C only) and then analyzed between 0 and 180 min later on the ADVIA 120. In addition, immunofluorescent flow cytometry was used to identify activated platelets and platelet-leukocyte aggregates. RESULTS: In blood stored with all three anticoagulants, the platelet count changed little, but the mean platelet volume (MPV) at first decreased and then increased, whereas the mean platelet component (MPC; an indicator of activation) changed in a reciprocal manner. The changes in MPV and MPC, which reflect platelet sphering and swelling, were greatest between 30 and 60 min in blood stored at ambient temperature, irrespective of which anticoagulant was used, and between 60 and 180 min when blood anticoagulated with E/C was stored at 4 degrees C. In all anticoagulants, the percentages of platelets expressing CD62P and of leukocytes in platelet-leukocyte aggregates increased significantly (P <0.01) over 180 min at ambient temperature. Only minimal (<2%) increases occurred when blood with E/C was stored at 4 degrees C. CONCLUSIONS: When determining platelet activation ex vivo on the ADVIA 120, blood should be collected into E/C, stored at 4 degrees C, and analyzed between 60 and 180 min later; these conditions ensure maximum platelet sphering without concurrent artifactual platelet activation.