Study Type – Diagnostic (cohort)
Level of Evidence 2b
What's known on the subject? and What does the study add?
Although non-recommended PSA testing has been reported in men younger than 40 years of age, there are few recognized data on PSA in younger American men, particularly younger African-American men, to provide age- and race-specific references.
Using data from an existing large study of young, male members of the US military, aged 28–36 years, the present study provides PSA reference distributions for young Caucasian-American men (median = 0.56, 95th percentile = 1.42, range: <0.01–3.34 ng/mL) and African-American men (median = 0.64, 95th percentile = 1.89, range: 0.12–6.45 ng/mL). Previous estimates from the literature are also summarized.
- • To provide race-specific prostate-specific antigen (PSA) reference distributions for young men less than 40 years of age who might have undergone non-recommended PSA testing because of their family history of prostate cancer or inadvertently as part of a standard panel of tests.
MATERIALS AND METHODS
- • We used data from a large existing study of young, male Caucasian- and African-American members of the US military with stored serum in the Department of Defense serum repository.
- • As part of this previous study, we selected a random sample of 373 Caucasian- and 366 African-American men aged 28–36 years with an archived serum specimen collected for standard military purposes from 2004 to 2006.
- • We measured serum total PSA concentration in this specimen using the Beckman Coulter Access Hybritech PSA assay.
- • The PSA level ranged from <0.01 to 3.34 ng/mL among Caucasian-American men, with a median of 0.56 ng/mL and a 95th percentile of 1.42 ng/mL.
- • The PSA level ranged from 0.12 to 6.45 ng/mL among African-American men, with a median of 0.64 ng/mL and 95th percentile of 1.89 ng/mL.
- • The PSA level was significantly higher in African- than in Caucasian-American men (P= 0.001).
- • The PSA estimates, together with those summarized from the literature, provide age- and race-specific PSA reference distributions for young men who might have undergone non-recommended PSA testing.
- • Comparisons by race could also begin to inform the timing of divergence of prostate cancer risk by race.