Background: The cut-off value of prostate-specific antigen velocity (PSAV) was investigated in relation to the initial prostate-specific antigen (PSA) value in subjects with initial values of 1.0-4.0 ng/mL, and the usefulness and limitations of PSAV as a screening test for prostate cancer were examined.
Methods: In this study, 4883 men who underwent mass screening for prostate cancer two or more times between 1987 and 1998 and had initial PSA levels of 1.0-4.0 ng/mL were investigated. The subjects ranged in age from 42 to 96 years (mean: 68.0 +/- 6.6 years). The cut-off value of PSAV was set at 0.1-1.5 ng/mL per year, and the sensitivity, specificity, efficiency and positive predictive value (PPV) of PSAV for detecting prostate cancer were determined according to the initial PSA value. A similar examination of the average PSAV was carried out in 2888 subjects with three or more visits for mass screening for prostate cancer.
Results: The diagnostic efficiency of PSAV was optimal with cut-off values of 0.3 and 0.75 ng/mL per year in those subjects with initial PSA levels of 1.0-1.9 and 2.0-4.0 ng/mL, respectively, but the PPV was low at 1.8% in subjects with initial PSA levels of 1.0-1.9 ng/mL. When the cutoff value of PSAV was set at 1.2 ng/mL per year in individuals with initial PSA levels of 1.0-1.9 ng/mL, the PPV increased to 7.3% and the sensitivity was 40%. The diagnostic efficiency of the average PSAV was optimal at the cut-off values of 0.2 and 0.4 ng/mL per year in subjects with initial PSA levels of 1.0-1.9 and 2.0-4.0 ng/mL, respectively, but the PPV was low at 2.2% in the subjects with initial PSA values of 1.0-1.9 ng/mL. When the cut-off value of PSAV was set at 0.75 ng/mL per year in individuals with initial PSA levels of 1.0-1.9 ng/mL, the PPV was 9.8% and the sensitivity was 46%.
Conclusion: It is possible to improve the diagnostic accuracy of prostate cancer screening using the cut-off value of PSAV and average PSAV in subjects with initial PSA levels of 1.0-4.0 ng/mL. The cut-off values of PSAV should be set at 1.2 and 0.75 ng/mL per year in individuals with initial PSA levels of 1.0-1.9 and 2.0-4.0 ng/mL, respectively. The cut-off values of the average PSAV should be set at 0.75 and 0.4 ng/mL per year in individuals with initial PSA levels of 1.0-1.9 and 2.0-4.0 ng/mL, respectively.