RESUMO
PURPOSE: We evaluated the significance of the P504S expression in prostate cancer and also the usefulness of the P504S/34betaE12 combined immunostaining method for diagnosing prostate cancer, and we did this by performing histological analysis of needle biopsy specimens. MATERIALS AND METHODS: Prostate tissue specimens were obtained from 83 patients with clinically suspected prostate cancer. A total of 54 prostate needle biopsy specimens were immunostained with an enzyme commonly overexpressed in prostate cancer(P504S) and also with an antibody against a basal cell marker(34betaE12). A total of 83 cases were immunostained with 34betaE12, including 29 cases that were stained with only with HMW- CK(34betaE12). RESULTS: P504S immunostaining was positive in 96.3%(26 of 27 cases) of the prostate cancer specimens. 34betaE12 immunostaining was positive in 97.2%(35 of 36 cases) of the benign prostate tissues. Of the 30 P504S positive immunostaining cases, 26 cases were prostate cancers, 3 cases were ASAP and 1 case was ASAP+PIN. Of the 36 34betaE12 positive immunostained cases, 35 cases were benign and 1 case was ASAP. In the P504S(+)/34betaE12(-) cases, there are no benign prostate lesions. There are no benign prostate lesions in the P504S(-)/34betaE12(+) cases, and all the cases were benign. There were no statistical correlations between the grade of P504S staining and the clinical parameters such as serum PSA, the clinical stage and the Gleason scores. CONCLUSIONS: Combining P504S as a positive marker for prostate cancer with 34betaE12 as a negative marker might improve the diagnostic performance.