[Five-year results of prostate specific antigen (PSA) screening in Yokosuka City--comparative study between PSA-screened group and non-screened group].

A mass screening of subjects for prostate specific antigen (PSA) was conducted to investigate whether this method is effective in detection of early stage prostate cancer. From 2001 to 2005, 1022 patients in Yokosuka City with pathologically diagnosed prostate cancer by using prostate needle biopsy were divided into screened (S: 276 patients) and non-screened (NS: 746 patients) groups. Clinical factors (mean age, PSA at diagnosis, clinical stage, Gleason score, WHO classification, cases of radical prostatectomy) were evaluated and analyzed. Statistical significance was analyzed by Mann-Whitney's U-test. The mean age was 70.7 and 72.7 (p<0.0001) in the S group and NS group, respectively; mean PSA at diagnosis was 10.5 and 18.6 ng/ml (P=0.0139); percentage of organ-confined disease (T2b or lower clinical stage), 75 and 55 (p<0.0001); percentage of non-metastatic diseases was 92 and 77 (p<0.001) and percentage of pathologically poor-risk cancer (8 or more Gleason score) was 22 and 38 (p=0.0004), respectively. In conclusion, PSA mass screening was found useful to detect early stage prostate cancer in Yokosuka City. Further studies should be conducted to determine whether PSA mass screening will be able to decrease mortality of prostate cancer.