Age‐Specific Reference Ranges for Prostate Specific Antigen in Young Men: Retrospective Study from the National Defense University

Abstract

Objectives: While controversial, the use of prostate specific antigen (PSA) testing is common and may reduce the morbidity and mortality associated with prostate cancer. The use of age-specific reference ranges (ASRRs) has been suggested to increase the sensitivity of the PSA test in younger men. The objective of this study was to determine the normal age-specific reference ranges for a large group of clinically cancer-free men and to compare these findings with similar studies. Materials and Methods: A retrospective chart review of PSA values was conducted on 1199 students from the National Defense University, Fort McNair, Washington, DC, who were matriculating between 1994 and July 1999. The AsXYM system using MEIA technology with monoclonal antibodies from Abbott laboratories was used to determine the PSA values. The mean, median, 95th percentile, 99th percentile, and range were calculated for each decade. Results: A total of 1123 students between the ages of 30 and 59 were included in the study (1105 with PSA levels ≤ 4.0 ng/ml). The largest number of students (67.4%) fell in the 40–49-year-old group. The median PSA level was 0.74 ng/ml. There was a significant correlation between age and PSA level for the 40–59-year-old age group (r = 0.06, p = 0.044). There was no significant correlation between age and PSA for the 40–49-year-old age group (r = 0.048, p = 0.192). The median PSA value and the 95th percentile increased from 0.7 and 2.3, respectively, in the 40–49-year-old age group to 0.8 and 2.7, respectively, in the 50–59-year-old age group. Conclusions: The results of this study indicate that PSA values in young men are quite low. The 95th percentile of PSA levels for men in their 40s and 50s was 2.3 and 2.7 ng/ml, respectively, which is significantly lower than the traditional normal value of 4.0 ng/ml. Although further prospective studies are needed, our data suggest that a lower PSA value threshold of 2.0 to 2.5 ng/ml for younger men is reasonable to dictate further evaluation.