Prostate-specific Antigen (PSA), PSA Density and Age-adjusted PSA Reference Values in Screening for Prostate Cancer: A Study of a Randomly Selected Population of 2,400 Men

Abstract

Prostate cancer screening with DRE, TRUS, and PSA testing was offered to 2,400 randomly selected men 55-70 years old. Among 1,782 examined, 65 (3.6%) men with prostate cancer were diagnosed. The PSA results were correlated to the diagnosis, the men's age, and the prostate volume. Least square regression analysis was used to calculate the 95% upper confidence intervals for PSA in each year of age in men without prostate cancer. The PPV was calculated for: (i) PSA > 4 ng/ml, (ii) PSAD > 0.15, (iii) PSAD > 0.20 and (iv) age-adjusted PSA reference values. A significant correlation was found between PSA and prostate volume, between PSA and age, and between the prostate volume and age. The calculated annual growth of the prostate was 1.6% and the annual increase in PSA was 2.4%. The age-adjusted upper PSA reference values for the three age categories studied (55-59, 60-64 and 65-70 years) were 5.2, 5.8, and 6.7 ng/ml, respectively. The PPVs for PSA > 4 ng/ml, PSAD > 0.15, PSAD > 0.20, and the age-adjusted PSA reference values were 17%, 14%, 22%, and 27%, respectively. Age-adjusted PSA or PSAD may increase the PPV compared to PSA > 4 ng/ml. The detection rate is, however, inadequate. A PSA cut-off at 4 ng/ml could therefore be maintained in men 55-70 years old. The median PSA values and median prostate volumes calculated for men with benign findings may serve as a reference in future studies.