SERUM PROSTATE-SPECIFIC ANTIGEN IN A COMMUNITY-BASED POPULATION OF HEALTHY JAPANESE MEN - LOWER VALUES THAN FOR SIMILARLY AGED WHITE MEN

Objective To determine whether the age-specific reference ranges for serum prostate-specific antigen (PSA) concentration generated for white men are applicable to other races. Patients and methods Three-hundred and thirty-five healthy Japanese men, aged 40-79 years, residing in the small fishing village of Shimamaki-mura, Japan, agreed to enter this prospective, community-based study, All underwent a detailed clinical evaluation that included a serum PSA determination, a digital rectal examination and a transrectal ultrasound, Two-hundred and eighty-six (85%) completed the prostatic evaluation and had no evidence of prostate cancer by any one of the three diagnostic tests; these men formed the study population on which all analyses were performed. Results The serum PSA concentration correlated directly with patient age (r = 0.33; P < 0.001) and prostatic volume (r = 0.57: P < 0.001), PSA density (PSAD) also was directly proportional to age (r = 0.30; P < 0.001), Adjusting for age, the serum PSA concentration was lower for Japanese men than for white men (P < 0.001), Thus, the recommended age-specific reference ranges (95th percentile) for serum PSA for Japanese were lower as well: 0.0-2.0 ng/mL for 40-49 years; 0.0-3.0 ng/mL for 50-59 years; 0.0-4.0 ng/mL for 60-69 years; and 0.0-5.0 ng/mL for 70-79 fears. Based on transrectal ultrasound-volume determinations, the lower serum PSA concentrations in Japanese men are due in large part to their smaller prostate glands as compared with white men (P < 0.001). Conclusions These findings confirm the earlier observations that serum PSA, prostatic volume and PSAD are age-dependent. However, because of physiological differences among the two races, partly due to the size of the prostate gland, the age-specific reference ranges for serum PSA are lower for Japanese men than for white men, Because of these racial differences, it is now crucial to conduct a similar investigation among black men.