Possibility of improving the acceptance rateof early detection testing for prostate cancerwith a one-step test for prostate-specific antigen in whole blood.

In order to increase the acceptance rate of early detection testing for prostate cancer, a qualitative prostate-specific antigen (PSA) one-step test has been developed. Determining the PSA level with this test system takes 10 min. The blood samples of 190 men were tested in this qualitative assay, which uses 50 microl of EDTA whole blood and in which the results are ascertained visually. Parallel samples were tested in serum-based, quantitative assays (Abbott Imx, EIA). The findings of the two kinds of assays were compared and evaluated regarding their correspondence (<4.0 and > or = 4.0 ng/ml). For the 74 blood samples in which the quantitative assay showed PSA levels <4.0 ng/ml, the PSA one-step test showed 83.8% correct negative results (corresponds to diagnostic specificity). For the 116 samples in which the classic assay showed PSA levels > or = 4.0 ng/ml, the one-step test showed 90.5% correct positive results (sensitivity). The noted deviations appear especially around the cut-off value of 4.0 ng/ml, i.e. within the PSA concentration range of 3.0 < 4.0 and 4.0 < 5.0 ng/ml. The qualitative PSA one-step test presented here demonstrates good reproducibility. It can be conducted by the patient and is easy to use. The test offers a simple, feasible method for early detection programs for prostate cancer. Copyright 1999 S. Karger AG, Basel