Clinical evaluation of serum prostatic specific antigen in prostatic cancer: simultaneous assays of prostatic specific antigen, gamma-seminoprotein and prostatic acid phosphatase in 113 newly diagnosed patients with prostatic cancer

Serum prostatic specific antigen (PA), gamma-seminoprotein (gamma-Sm) and prostatic acid phosphatase (PAP) levels were measured in 113 untreated patients with prostatic cancer and in 137 patients with benign prostatic hypertrophy (BPH). We used a PA-TESTWAKO enzyme immunoassay kit, gamma-Sm enzyme immunoassay kit and PAP radioimmunoassay kit. Of the 113 patients, 81.4%, 73.5% and 69%, respectively, were detectable using a single assay. PA was more sensitive than the other two markers in all stages, especially in localized disease (stages A, B and C). Using the BPH group as a negative control, specificities of PA, gamma-Sm and PAP were 85.4%, 81.0% and 94.2%, respectively. Efficiency was, respectively, 81.2%, 79.6% and 82.8%. In the follow up period, 15 patients presented disease progression. At the time of clinical detectable progression, the sensitivities of PA and gamma-Sm were both 100% (15/15), while 67% (10/15) for PAP. Concerning the sensitivity within 6 months prior to progression, gamma-Sm and PA tended to be more sensitive than PAP in early detection of disease progression. This study shows that PA is more reliable than gamma-Sm and PAP in detecting and staging of prostatic cancer. gamma-Sm and PA appear to be more reliable in earlier prediction of disease progression.