[Measurement of serum PSA by DELFIA PSA kit and its application for mass screening. The Gunma Urological Oncology...

The significance of prostate specific antigen (PSA) measured by DELFIA PSA kit in the 1,177 serum samples examined by mass screening for prostate cancer was evaluated. All subjects were examined by questionnaire, digital rectal examination (DRE) and prostatic acid phosphatase (PAP) and the subjects in whom prostate cancer was suspected from abnormal DRE and/or elevated PAP were recommended to receive the secondary screening for the presence of prostate cancer. All serum specimens used for this study were kept in our serum bank. The cut-off value was investigated between non-cancer subjects (diagnosed as normal, voiding disturbance or BPH) and prostate cancer patients. When the cut-off value was 2.89 ng/ml, the sensitivity, specificity and accuracy as prostate marker was 80.6%, 90.0% and 89.4%, respectively. Therefore, the cut-off value was determined as 3.0 ng/ml. The significance of PSA was retrospectively evaluated compared to PAP in the subjects examined by our mass screening. Twenty eight of the 39 palpable prostate cancers which could not be detected from the PAP level were detected from the PSA level, namely the sensitivity of the detection using the PSA level is more excellent than that using PAP. However, the false negative rate obtained using PSA was high (30.3%) in the patients with stage B disease. The relationship among serum PSA concentration, prostate size estimated by DRE and age was investigated. PSA was increased with age and prostate size. This estimation should be confirmed by using an ultrasonography because the prostate size obtained by DRE is inaccurate as compared with that obtained by ultrasonography.