Preliminary Results of Clinical Evaluation of the Free/Total Prostate-Specific Antigen Ratio in a Multicentric Study

1996 ◽  
Vol 82 (6) ◽  
pp. 543-549 ◽  
Author(s):  
Riccardo Mione ◽  
Giuseppe Aimo ◽  
Emilio Bombardieri ◽  
Alberto Cianetti ◽  
Mario Correale ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Prostate Specific Antigen ◽  
Dose Range ◽  
Specific Antigen ◽  
Diagnostic Efficiency ◽  
Clinical Value ◽  
Multicentric Study ◽  
Free Psa ◽  
Prostate Biopsies ◽  
Total Psa

Aims and Background The free/total (F/T) prostate-specific antigen (PSA) ratio is probably the most promising tool proposed to increase the specificity of PSA in the diagnosis of prostate cancer. The aim of the present study was to evaluate the clinical value of the F/T ratio in 138 patients with benign hyperplasia, 101 with untreated prostate cancer, and 176 apparently healthy men. Methods We used a new immunometric assay of free PSA (FPSA-RIACT, CIS Diagnostici, Italy) which has shown good analytical performance; sample handling and storage under routine conditions did not affect the antigen stability. Results The diagnostic efficiency of the F/T ratio was significantly better than that of total PSA. In patients with total PSA ranging from 4 to 10 ng/ml, at a specificity level of 95% total PSA showed a sensitivity of 7%, whereas the sensitivity of F/T increased to 70%. Using the F/T ratio as a decision tool in association with total PSA and considering all cases candidate to biopsy (total PSA greater than 3.79 ng/ml corresponding to the 95% level), we demonstrated a 35% reduction of total biopsies that would have been required on the basis of total PSA alone. Conclusions The determination of the percentage of F/T serum PSA significantly improves the specificity of the marker, particularly in the 4-10 ng/ml dose range where unnecessary prostate biopsies can be reduced.

scholarly journals The Combination of Human Glandular Kallikrein and Free Prostate-specific Antigen (PSA) Enhances Discrimination Between Prostate Cancer and Benign Prostatic Hyperplasia in Patients with Moderately Increased Total PSA

1999 ◽  
Vol 45 (11) ◽  
pp. 1960-1966 ◽  
Author(s):  
Angeliki Magklara ◽  
Andreas Scorilas ◽  
William J Catalona ◽  
Eleftherios P Diamandis
Keyword(s):  
Prostate Cancer ◽  
Benign Prostatic Hyperplasia ◽  
Prostate Specific Antigen ◽  
Prostatic Carcinoma ◽  
Specific Antigen ◽  
Area Under The Curve ◽  
Prostatic Hyperplasia ◽  
Free Psa ◽  
Glandular Kallikrein ◽  
Total Psa

Abstract Background: Prostate-specific antigen (PSA) is the most reliable tumor marker available and is widely used for the diagnosis and management of prostate cancer. Unfortunately, PSA cannot distinguish efficiently between benign and malignant disease of the prostate, especially within the range of 4–10 μg/L. Among the refinements developed to enhance PSA specificity is the free/total PSA ratio, which is useful in discriminating between the two diseases within the diagnostic “gray zone”. Recent data indicate that human glandular kallikrein (hK2), a protein with high homology to PSA, may be an additional serum marker for the diagnosis and monitoring of prostate cancer. Methods: We analyzed 206 serum samples (all before treatment was initiated) from men with histologically confirmed benign prostatic hyperplasia (n = 100) or prostatic carcinoma (n = 106) with total PSA in the range of 2.5–10 μg/L. Total and free PSA and hK2 were measured with noncompetitive immunological procedures. Statistical analysis was performed to investigate the potential utility of the various markers or their combinations in discriminating between benign prostatic hyperplasia and prostatic carcinoma. Results: hK2 concentrations were not statistically different between the two groups of patients. There was a strong positive correlation between hK2 and free PSA in the whole patient population. hK2/free PSA ratio (area under the curve = 0.69) was stronger predictor of prostate cancer than the free/total PSA ratio (area under the curve = 0.64). At 95% specificity, the hK2/free PSA ratio identified 30% of patients with total PSA between 2.5–10 μg/L who had cancer. At 95% specificity, the hK2/free PSA ratio identified 25% of patients with total PSA between 2.5 and 4.5 μg/L who had cancer. Conclusions: Our data suggest that hK2 in combination with free and total PSA can enhance the biochemical detection of prostate cancer in patients with moderately increased total PSA concentrations. More specifically, the hK2/free PSA ratio appears to be valuable in identifying a subset of patients with total PSA between 2.5 and 4.5 μg/L who have high probability of cancer and who should be considered for biopsy.

Discordant prostate specific antigen test results despite WHO assay standardization

2018 ◽  
Vol 33 (3) ◽  
pp. 275-282 ◽  
Author(s):  
Martin Boegemann ◽  
Christian Arsov ◽  
Boris Hadaschik ◽  
Kathleen Herkommer ◽  
Florian Imkamp ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Early Detection ◽  
Specific Antigen ◽  
Test Results ◽  
Serum Samples ◽  
Prostate Specific Antigen Test ◽  
Free Psa ◽  
Prostate Biopsies ◽  
Cancer Early Detection ◽  
Total Psa

Introduction: Total PSA (tPSA) and free PSA (fPSA) are the most commonly used biomarkers for early detection of prostate cancer. Despite standardization efforts, many available PSA assays may still produce discordant results. In the present study, we compared four PSA assays calibrated to the WHO standards 96/670 and 96/668 for tPSA and fPSA, respectively. Methods: Within the scope of the Prostate Cancer Early Detection Study Based on a ‘‘Baseline’’ PSA Value in Young Men (PROBASE), we tested tPSA and fPSA in serum samples from 50 patients in the four different PROBASE sites using four WHO-calibrated assays from Roche (Elecsys, Cobas), Beckman-Coulter (Access-II) and Siemens (ADVIA Centaur). The comparison was performed using the Passing–Bablok regression method. Results: Compared to Access, the median tPSA levels for Centaur, Elecsys, and Cobas were +3%, +11%–20%, and +17%–23%, respectively, while for median fPSA levels the differences for Centaur, Elecsys, and Cobas were +49%, +29%–31%, and +22%, respectively. Discussion: Despite all investigated assays being WHO-calibrated, the Elecsys and Cobas tPSA assays produced considerably higher results than the Access and Centaur assays. Differences in fPSA-recovery between all investigated assays were even more pronounced. When applying the tPSA cutoff of 3.1 μg/L recommended for WHO-calibrated assays, the use of higher calibrated assays may lead to unnecessary prostate biopsies. Conversely, if the historical threshold of 4 μg/L is applied when using WHO-calibrated assays, it could lead to falsely omitted prostate biopsies.

On the Clinical Usefulness of the Free-to-Total Prostate-Specific Antigen Ratio

2006 ◽  
Vol 21 (1) ◽  
pp. 1-5 ◽  
Author(s):  
S. Ciatto ◽  
T. Rubeca ◽  
R. Franceschini ◽  
C. Trevisiol ◽  
M. Confortini ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Prostate Specific Antigen ◽  
Specific Antigen ◽  
Clinical Usefulness ◽  
Clinical Use ◽  
Prostate Biopsies ◽  
Total Prostate Specific Antigen ◽  
Total Psa

The free-to-total prostate-specific antigen ratio (F/T PSA) is associated with the presence of prostate cancer and is thus used as an indicator for suspicion of prostate cancer and as a determinant for biopsy. We reviewed a recent retrospective series of 966 consecutive prostate biopsies where F/T PSA was blindly determined and did not influence biopsy indication. We simulated the association of F/T PSA with biopsy outcome and its impact as a biopsy determinant. When adopting an F/T PSA cutoff of 10%, 13%, 16% or 20% among random sextant biopsies in the 4–10 ng/mL total PSA range, the sensitivity was 15%, 37%, 55% and 72% and the specificity 89%, 80%, 64% and 44%, respectively. Using F/T PSA as a biopsy determinant, from 1.7 to 2.6 cancer biopsies would have been delayed to avoid 10 benign biopsies. As this balance is not acceptable, F/T PSA has no role as a biopsy indicator and its clinical use is questionable.

scholarly journals Novel immunoassay for the measurement of complexed prostate-specific antigen in serum

1998 ◽  
Vol 44 (6) ◽  
pp. 1216-1223 ◽  
Author(s):  
W Jeffrey Allard ◽  
Zeqi Zhou ◽  
Kwok K Yeung
Keyword(s):  
Prostate Cancer ◽  
Monoclonal Antibody ◽  
Prostate Specific Antigen ◽  
Specific Antigen ◽  
Binding Properties ◽  
Prostate Disease ◽  
Free Psa ◽  
Total Psa ◽  
Benign Prostate ◽  
Artificial Mixtures

Abstract Serum prostate-specific antigen (PSA) is an effective diagnostic tool for detection of prostate cancer (CaP) at an early and potentially curable stage, but specificity is low. Studies have shown that the proportion of serum PSA complexed with α-1-antichymotrypsin (ACT) is higher in men with CaP than in men with benign prostate disease. We developed a novel immunoassay for complexed PSA based on the unique binding properties of a monoclonal antibody that fails to bind free PSA in the presence of antibodies specific for free PSA. The assay measured mixtures of free and complexed PSA accurately, and the measured values of free + complexed PSA in artificial mixtures and in patient sera were equivalent to the measured value of total PSA. Both the serum concentration and the proportion of complexed PSA was substantially higher in patients with CaP compared with patients with benign prostate disease. The cPSA assay may have utility in improving specificity in screening for prostate cancer.

Prostate-Specific Antigen (PSA) Isoform p2PSA in Combination with Total PSA and Free PSA Improves Diagnostic Accuracy in Prostate Cancer Detection

2010 ◽  
Vol 57 (6) ◽  
pp. 921-927 ◽  
Author(s):  
Flip H. Jansen ◽  
Ron H.N. van Schaik ◽  
Joep Kurstjens ◽  
Wolfgang Horninger ◽  
Helmut Klocker ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Diagnostic Accuracy ◽  
Prostate Specific Antigen ◽  
Cancer Detection ◽  
Specific Antigen ◽  
Prostate Cancer Detection ◽  
Free Psa ◽  
Total Psa

Clinical evaluation of free PSA/Total PSA (Prostate-specific Antigen) ratio in the diagnosis of prostate cancer

1997 ◽  
Vol 33 (8) ◽  
pp. 1226-1229 ◽  
Author(s):  
X Filella ◽  
J Alcover ◽  
R Molina ◽  
A Rodríguez ◽  
P Carretero ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Prostate Specific Antigen ◽  
Clinical Evaluation ◽  
Specific Antigen ◽  
Free Psa ◽  
Total Psa

scholarly journals Discrimination of Prostate Cancer from Benign Disease by Plasma Measurement of Intact, Free Prostate-specific Antigen Lacking an Internal Cleavage Site at Lys145-Lys146

2001 ◽  
Vol 47 (8) ◽  
pp. 1415-1423 ◽  
Author(s):  
Pauliina Nurmikko ◽  
Kim Pettersson ◽  
Timo Piironen ◽  
Jonas Hugosson ◽  
Hans Lilja
Keyword(s):  
Prostate Cancer ◽  
Prostate Specific Antigen ◽  
Screening Program ◽  
Specific Antigen ◽  
Benign Disease ◽  
Free Psa ◽  
Plasma Measurement ◽  
Edta Plasma ◽  
Capture Antibody ◽  
Total Psa

Abstract Background: The proportion of free prostate-specific antigen (PSA) is higher in the sera of patients with benign prostatic hyperplasia compared with patients with prostate cancer (PCa). We developed an immunoassay that measures intact, free PSA forms (fPSA-I), but does not detect free PSA that has been internally cleaved at Lys145-Lys146 (fPSA-N), and investigated whether this form could discriminate patients with PCa from those without PCa. Methods: The assay for fPSA-I uses a novel monoclonal antibody (MAb) that does not detect PSA that has been internally cleaved at Lys145-Lys146. A MAb specific for free PSA was used as a capture antibody, and purified recombinant proPSA was used as a calibrator. The concentrations of fPSA-I, free PSA (PSA-F), and total PSA (PSA-T) were analyzed in EDTA-plasma samples (n = 276) from patients who participated in a screening program for PCa (PSA-T, 0.83–76.3 μg/L). Results: The detection limit of the fPSA-I assay was 0.035 μg/L. Both the measured concentrations of fPSA-I and the concentrations of fPSA-N (calculated as PSA-F − fPSA-I) provided statistically significant discrimination of the two clinical groups. By contrast, PSA-F did not discriminate between these groups. Each of the ratios fPSA-I/PSA-F, fPSA-N/PSA-T, and PSA-F/PSA-T separated cancer samples from noncancer samples in a statistically significant manner (P <0.0001). The ratio fPSA-I/PSA-F was significantly higher in cancer (median, 59%) compared with noncancer samples (47%). Conclusions: The ratio fPSA-I/PSA-F is significantly higher in cancer compared with noncancer. The percentages of both fPSA-N/PSA-T and fPSA-I/PSA-F may provide interesting diagnostic enhancements alone or in combination with other markers and require further studies.

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