The present status of convergence in PSA reference values--from the surveillance in the Tokai-Hokuriku district

摘要

The number of patients with prostatic cancer is recently increasing in Japan and it is well known that serum PSA determination is routinely used as a tumor marker of prostatic cancer. However, the reference values of PSA are widely varied, because the reactivities of the antibody to free PSA and ACT-PSA are different in each kit. Thus, there is no compatibility among values determined by available kits. In this study, we sent a questionnaire on PSA determination to 180 hospitals with more than 200 beds. The recovery rate to the questionnaire was 80.5% (145/180) and the determination was performed in house at 47 hospitals out of 145. Stamey in Stanford University recommended to set the ratio of complex PSA to free PSA 9:1 in the reference material. It is expected that PSA ad hoc committee in Japan reported that the inter-kit variability is becoming small. It can be said that the standardization for PSA determination is progressing. To discriminate prostatic cancer from benign prostatic hypertrophy, freePSA ratio or complex ACT-PSA is recommended. Further accumulation of data on PSA will be necessary to confirm this matter.