Age-related reference levels of serum prostate-specific antigen among taiwanese men without clinical evidence of prostate cancer

Background: To determine the normal distribution of serum prostate-specific antigen (PSA) levels in Taiwanese men without clinical evidence of prostate cancer. Methods: Between August 2006 and October 2007, healthy Taiwanese men undergoing a routine health examination in our hospital were recruited into the study. All men received a digital rectal examination (DRE) and serum PSA determination and some received a transrectal ultrasound (TRUS). Men with normal DRE findings, and PSA < 4.0 ng/ml, PSA between 4.0 ng/ml and 20 ng/ml with a negative TRUS or abnormal TRUS findings (hypoechoic lesion or others) with a negative biopsy were defined as clinically free of prostate cancer. Results: A total of 7803 participants without clinical evidence of prostate cancer were included in the study. The median PSA value (95^th percentile range) was 0.896 ng/ml (3.329) for men 50-59 years old; 1.151 ng/ml (5.114) for men 60-69 years old; 1.623 ng/ml (6.237) for men 70-79 years old and 1.754 ng/ml (6.613) for men older then 80 years. The serum PSA values correlated with age (r = 0.3078, p < 0.001). There were small changes in the median and 95^th percentile PSA values in men younger than 50 years old, but large increases in those older than 50 years. Conclusions:These findings confirm that the serum PSA is directly correlated with age, and offer more efficient PSA reference values for prostate cancer screening tests in Taiwanese men.