Clinical characteristics of prostate cancer in Japanese men in the eras before and after serum prostate‐specific antigen testing

Abstract

We retrospectively reviewed a large series of Japanese men with histologically proven prostate cancer to assess the clinical characteristics of the cancer in three different eras of prostate cancer management since prostate-specific antigen (PSA) testing started in 1988. The medical records of 1125 patients treated between 1975 and 2002 were reviewed with respect to age, chief complaints, clinical stage, tumor grade, treatment options at each stage, and prognosis. We classified the patients as follows: those treated in the pre-PSA era between 1975 and 1988 (n=182), those treated in the PSA era between 1988 and 1997 (n=301; PSA era phase 1) and the PSA era between 1998 and 2002 (n=642; PSA era phase 2). Compared with the pre-PSA era, there were significant increases in the proportion of well-differentiated adenocarcinoma with respect to the biopsy tumor grade (24 vs 35%, P<0.01), in the proportion of linically organ-confined disease (21 vs 43%, P<0.001), and in the proportion of patients who underwent radical prostatectomy (13%vs 20%, P<0.01) after PSA testing was introduced. In addition, there was a significant difference in the proportion of subjects who were 70--79 years of age between the pre-PSA era (52%, 95/182) and the PSA era phase 2 (42%, 270/642, P<0.05). There was also a significant difference in the proportion of patients who underwent surgical castration between the pre-PSA era (78%) and PSA era phase 2 (10%, P<0.001). The proportion of patients participating in prostate cancer screening increased from 3% (pre-PSA era) to 11% (PSA era phase 1 and PSA era phase 2, P<0.05). In all clinical stages, there were significant differences between the pre- and post-PSA eras in cause-specific survival rates (5-year: 74 vs 94% in stages A and B, P<0.01; 54 vs 89% in stage C, P<0.001; 32 vs 53% in stage D, P<0.001). Migrations in the age of patients (toward younger patients), the stage of the cancer (towards earlier stages) and the histological findings (toward favorable findings), in addition to changes in treatment options, have contributed to the prolonged survival of Japanese men with prostate cancer after the PSA testing was introduced.