Age-specific reference ranges for prostate specific antigen-total and free in patients with prostatitis symptoms and patients at risk.
Background: Prostate-specific antigen (PSA) is a tumor marker helpful in the diagnosis and follow-up of prostate cancer. However, PSA level may rise due to other causes than prostate cancer such as benign prostatic hyperplasia (BPH), acute prostatitis, chronic bacteria and a bacterial prostatitis. Total serum PSA (TPSA) and free prostate-specific antigen (FPSA) levels of patients with prostatitis symptoms as well as these levels in male population at risk but without clinical prostatic diseases (>40-years-old) with regard to age should be documented in order to increase the sensitivity and specificity of PSA in prostate carcinoma.
Methods: A comprehensive urological examination was performed on 1150 male patients over the age of 40 with prostatism symptoms from the random-sample community based in with no diagnostic prostate cancer. Men with PSA level 4.1 ng/ml or greater were referred for biopsy and those with positive biopsies or with medical record, cancer registry, or self-reported evidence of prostate cancer were excluded. Data were studied as a function of age to determine the usefulness of measuring TPSA and FPSA as screening tests for risk patient's cancer.
Results: Because of the greater variability at older ages, the 95th percentile increased faster than the median, the following age-specific reference ranges of TPSA and FPSA for patients with prostatism symptoms were as follows: 3.1 and 0.7 ng/ml for the age group 40-49 years, 4.4 and 0.89 ng/ml for the age group 50-59 years, 5.6 and 1.3 ng/ml for the age group 60-69 years, and 6.3 and 1.8 ng/ml for age group 70-79 years. There was a continuous increase in TPSA and FPSA means and medians with significant correlation (P<0.001, P<0.005) and advancing age group. The aim of this study was to find out age-specific values and ranges of TPSA and FPSA in patients with prostatism symptoms to ensure low false-positive biopsy rates.