Ethnic differences in distribution of serum prostate-specific antigen: a study in a healthy Chinese male population

Abstract

Objectives: To evaluate the normal distribution of serum prostate-specific antigen (PSA) levels in healthy Chinese men, because, until recently, studies conducted to establish normal serum PSA values have not involved a Chinese population.

Methods: Between September 1999 and December 2001, 1096 healthy Chinese men aged 23 to 85 years, who had undergone a routine health examination, were recruited to this study. All underwent detailed clinical examinations, including serum PSA determination and digital rectal examination. All men with abnormal digital rectal examination findings and/or an abnormal serum PSA level (greater than 4.0 ng/mL) underwent transrectal ultrasound-guided sextant biopsy.

Results: The median serum PSA concentration was 0.50 ng/mL (95th percentile 1.20) for men 23 to 29 years old (n = 77); 0.55 ng/mL (95th percentile 1.21) for men 30 to 39 years old (n = 189); 0.54 ng/mL (95th percentile 1.23) for men 40 to 49 years old (n = 233); 0.82 ng/mL (95th percentile 2.35) for men 50 to 59 years old (n = 177); 0.93 ng/mL (95th percentile 3.20) for men 60 to 69 years old (n = 265); and 1.17 ng/mL (95th percentile 3.39) for men 70 years old or older (n = 155). The serum PSA concentration correlated with age (P <0.001), with an increase of approximately 1.1% annually. No change occurred in the median serum PSA value and 95th percentile in men younger than 50 years old; a gradual increase was observed in men older than 50 years. In those 50 years old or older, the median and 95th percentile serum PSA values for Chinese men were significantly lower than those for other races and even for other Asian men.

Conclusions: These findings further confirm that the serum PSA level correlates with age. Moreover, the distribution and cutoff value of the serum PSA level differs along ethnic lines. In addition, our findings raise the question of whether lowering the PSA cutoff may enhance the detection of cancer in Chinese men who have the lowest prostate cancer rate.