Background: It is relevant to highlight that there is not a precise and perfect report on either 95 percentile value (upper limit of normal range) or on appropriate reference intervals for serum PSA in Iranian population.
Objective: To determine age-specific reference ranges for serum prostate-specific antigen (PSA) concentration and PSA density (PSAD) and prostate volumes in a population of healthy Iranian men.
Methods: Nine-hundred and thirteen healthy Iranian men, aged 50-79 years, underwent a detailed clinical evaluation including a digital rectal examination, a serum PSA determination (DRE) and transrectal ultrasound (TRUS). PSA test was performed on 666 of the subjects and TRUS was done on 633 of them. None of the subjects had any evidence of prostate cancer by any one of the three diagnostic tests and had no history of Lower Urinary Tract Symptoms (LUTS). Age specific ranges for PSA levels, PSA density and prostate volume were determined.
Results: The serum PSA concentration correlated directly with the subjects' age (r=0.280; p<0.001) and prostatic volume (r=0.327; p<0.001). Also prostatic volume was directly proportional to age (r=0.197; p<0.001).The serum PSA ranges (95th percentile) for each age range in Iranian men were: 0.00-2.61 ng/ml for 50-59 years; 0.00-3.59 ng/ml for 60-69 years; and 0.00-4.83 ng/ml for 70-79 years. The respective prostate volumes were: 14-59, 16-66 and 18-73ml. Also respective PSA densities were: 0.00-0.076, 0.00-0.10 and 0.00-0.14 ng/ml/ml.
Conclusion: The present study confirms earlier reports that serum PSA levels and prostate volume and PSAD are age- and race- dependent, so it is appropriate to have age- specific reference ranges for these variables in various communities around the world. This will increase the positive predictive value of PSA estimation in the diagnosis of prostate cancer in different communities.