Relationship of prostate-specific antigen levels to prostate volume and age in mass screening subjects

To evaluate the relationship between prostate-specific antigen (PSA) levels and prostate volume and age in a mass screening for prostatic disease, a total of 1,162 examinees from one Japanese prefecture who were over 45 years of age underwent a mass screening for prostatic disease that used the Hybritech (Tandem(R)RIA) kit, and the prostate volume was estimated by transabdominal ultrasonography. Differences among several groups of men according to prostate volume and age were examined by multiple comparisons using ranks. When some subjects visited several times, the data of the first visit were adopted only. The total number of individual subjects in this study was 589 men. The multiple comparisons using ranks and 10-year age brackets revealed that the levels of PSA showed significant differences between only two pairs of groups stratified by age. In contrast, the levels of PSA showed significant differences among seven pairs of groups stratified by the prostate volume according to 10-ml brackets. When a logarithmic transformation of the serum levels of PSA was used, the results showed the same tendencies. From the results of the present study, it can be said that the PSA reference range calculated with stratified prostate volume might be more useful in the detection of prostate cancer than that calculated with stratified age.