Prostate-specific antigen kinetics in screen-detected prostate cancer in Japan

It would be of value to compare the features of prostate cancer detected in various screening series around the world. Recently, some studies have demonstrated the value of pretreatment prostate-specific antigen (PSA) kinetics in predicting the outcome of radical prostatectomy and radiotherapy for men with localized prostate cancer. Therefore, the distribution of PSA velocity (PSAV) or PSA doubling time in screen-detected prostate cancer might be objective parameters to investigate how well each national screening system is working.

From 1992 to 2004, 957 men with prostate cancer were detected by screening in Gunma Prefecture, Japan. Of those, 275 men (29%) detected with consecutive screening tests participated in the present study. The PSAV was calculated by the PSA change between the most recent screening test and cancer diagnosis and also by linear regression analysis. The PSA doubling time was also calculated for 146 men who underwent screening at least three times.

The median PSAV was 1.3 ng/mL/yr in those with Stage T1cN0M, 1.1 ng/mL/yr in those with T2N0M0, and 2.1 ng/mL/yr in those with T3N0M0. The percentage of men with a PSAV (linear regression analysis) greater than 2.0 ng/mL/yr was 13%, 12%, and 49% in men with clinical Stage T1cN0M0, T2N0M0, and T3N0M0, respectively. The median PSA doubling time was 57.1, 51.7, and 28.0 months for those with T1cN0M0, T2N0M0, and T3N0M0, respectively.

Patients with prostate cancer with aggressive features are still detected in the population-based screening system in Japan. Even in Japan, where PSA screening is perhaps the most widespread among Asian countries, the screening system might be still immature compared with the systems in the United States and Western Europe.