Prostate Markers Research and Reference Ranges

What is Prostate Specific Antigen or PSA?

PSA is a protein enzyme produced by the prostate and mainly found in the semen, with very small amounts released into the bloodstream. It is used as a “disease marker” to check for prostate cancer.

When there’s a problem with the prostate, such as the development and growth of prostate cancer, more PSA can be released.

PSA eventually reaches a level where it can be easily detected in the blood. This can be the first indicator of prostate cancer.

PSA testing is the current test of choice for prostate cancer screening in conventional medicine.

Doctors look at the PSA level over time, compare it with prior test results, and consider whether a rising PSA could have a benign (non-cancer) explanation.

Other causes include prostate inflammation, benign prostate enlargement, or a urinary tract infection.

As the PSA number goes up, the chance that cancer is present increases.

In conventional medicine, a Total PSA > 4.0 ng/mL triggers a follow-up Free PSA and % Free PSA test.

% Free PSA is the most useful diagnostic indicator for a cancer diagnosis. 

PSA, Total – Research for Reference Ranges Used in LabSmarts

PSA, Total

    • Reference ranges adjusted automatically for the following criteria:
    1. Males ages: 0-39, 40-49, 50-59, 60-69, 70+ (except for white males who have ranges for 70-79 and 80+)
    2. Caucasian-American (White), Asian, and Other ethnicities in LabSmarts use the same ranges.
    3. African American males have their own ranges for each age group listed above, typically with higher optimal and lab ranges.
    4. Hispanic (Mexican American) males have their own ranges for each age group 40 and above, typically with lower optimal and lab ranges.
    5. There is no indication that Hispanic males require different cutoffs for ages less than 40, so they have the same ranges as white men in LabSmarts.
    6. PSA testing is not clinically indicated in females, and if tested, will most likely be undetected. Normal values in healthy women are typically <0.01 ng/mL (below the detection limit of standard assays).
    • Males ages 0-39
    1. Sutcliffe S, Pakpahan R, Sokoll LJ, et al. Prostate-specific antigen concentration in young men: new estimates and review of the literature. BJU Int. 2012;110(11):1627-1635. [PubMed]
    2. Caucasian-American (White) and Hispanic (Mexican American)
      1. Optimal Max = 0.56 ng/mL
      2. Lab Max = 1.42 ng/mL
      3. Alarm Max = 2.0 ng/mL
    3. African American
      1. Optimal Max = 0.64 ng/mL
      2. Lab Max = 1.89 ng/mL
      3. Alarm Max = 2.0 ng/mL
    • Males ages 40+ ≫ Alarm Max for Caucasian-American (White), African American, and Hispanic (Mexican American)
    1. Wei JT, Barocas D, Carlsson S, et al. Early Detection of Prostate Cancer: AUA/SUO Guideline Part I: Prostate Cancer Screening. J Urol. 2023;210(1):46-53. [PubMed]
      1. 40-49 = 2.5 ng/mL
      2. 50-59 = 3.5 ng/mL
      3. 60-69 = 4.5 ng/mL
      4. 70+ = 6.5 ng/mL
    • Males ages 40+ ≫ Optimal Max (50th percentile) and Lab Max (90th percentile) [unless otherwise noted]
    1. Lacher DA, Thompson TD. Total, Free, and Percent Free Prostate-Specific Antigen Levels among U.S. Men, 2001–04. [CDC]
    2. We capped the lab max at 4.0 ng/mL, where the CDC study had higher values for the older ages, to align with current clinical practice (Labcorp and Quest upper limits).
    3. Caucasian-American (White) Males ages 40+ (ng/mL)
      1. 40-49: Optimal ≤ 0.7, Lab Max = 1.6
      2. 50-59: Optimal ≤ 0.9, Lab Max = 2.4
      3. 60-69: Optimal ≤ 1.1, Lab Max = 3.4
      4. 70-79: Optimal ≤ 1.5, Lab Max = 4.0 (Labcorp and Quest upper limit)
      5. 80+: Optimal ≤ 1.9, Lab Max = 4.0 (Labcorp and Quest upper limit)
    4. African American Males ages 40+ (ng/mL)
      1. 40-49: Optimal ≤ 0.7, Lab Max = 1.73
      2. 50-59: Optimal ≤ 0.8, Lab Max = 2.8
      3. 60-69: Optimal ≤ 1.5, Lab Max = 3.7 (lower end of CI for 90th percentile)
      4. 70+: Optimal ≤ 2.16 (geometric mean), Lab Max = 4.0 (Labcorp and Quest upper limit)
    5. Hispanic (Mexican American) Males ages 40+ (ng/mL)
      1. 40-49: Optimal ≤ 0.71, Lab Max = 1.4
      2. 50-59: Optimal ≤ 0.9, Lab Max = 2.48
      3. 60-69: Optimal ≤ 1.0, Lab Max = 3.39
      4. 70+: Optimal ≤ 1.6, Lab Max = 4.0 (Labcorp and Quest upper limit)

PSA, Free – Research for Reference Ranges Used in LabSmarts

PSA, Free

    • Free PSA (ng/mL) is not a valid diagnostic indicator of the potential for prostate cancer, but it is needed to calculate the % Free PSA, which is the best diagnostic indicator.
    • Reference ranges adjusted automatically for the following criteria:
    1. Males ages: 0-49, 50-59, 60-69, 70+ (except for white males who have ranges for 70-79 and 80+)
    2. There are no established ranges for males younger than 40, so we are using the same ranges for ages 0-49 for each of the 3 ethnicities.
    3. Caucasian-American (White), Asian, and Other ethnicities in LabSmarts use the same ranges.
    4. African American males have their own ranges for each age group listed above, typically with higher optimal and lab ranges.
    5. Hispanic (Mexican American) males have their own ranges for each age group 40 and above, typically with lower optimal and lab ranges.
    6. PSA testing is not clinically indicated in females, and if tested, free PSA will most certainly be undetected.
      • Males ages 40+ ≫ Optimal Max (50th percentile), Lab Max (10th percentile), and Alarm Max (5th percentile) [unless otherwise noted]
      1. Lacher DA, Thompson TD. Total, Free, and Percent Free Prostate-Specific Antigen Levels among U.S. Men, 2001–04. [CDC]
      2. Caucasian-American (White) Males (ng/mL)
        1. Ages 0-49: Optimal ≥ 0.22, Lab Min = 0.10, Alarm Min 0.08
        2. Ages 50-59: Optimal ≥ 0.24, Lab Min = 0.12, Alarm Min 0.08
        3. Ages 60-69: Optimal ≥ 0.32, Lab Min = 0.11, Alarm Min 0.09
        4. Ages 70-79: Optimal ≥ 0.43, Lab Min = 0.15, Alarm Min 0.10
        5. Ages 80+: Optimal ≥ 0.56, Lab Min = 0.13, Alarm Min 0.08
      3. African American Males (ng/mL)
        1. Ages 0-49: Optimal ≥ 0.23, Lab Min = 0.11, Alarm Min 0.10
        2. Ages 50-59: Optimal ≥ 0.27, Lab Min = 0.13, Alarm Min 0.10
        3. Ages 60-69: Optimal ≥ 0.42, Lab Min = 0.14, Alarm Min 0.10
        4. Ages 70+: Optimal ≥ 0.56, Lab Min = 0.15, Alarm Min 0.10
      4. Hispanic (Mexican American) Males (ng/mL)
        1. Ages 0-49: Optimal ≥ 0.21, Lab Min = 0.12, Alarm Min 0.08
        2. Ages 50-59: Optimal ≥ 0.23, Lab Min = 0.09, Alarm Min 0.07
        3. Ages 60-69: Optimal ≥ 0.28, Lab Min = 0.10, Alarm Min 0.07
        4. Ages 70+: Optimal ≥ 0.42, Lab Min = 0.13, Alarm Min 0.10

PSA, % Free – Research for Reference Ranges Used in LabSmarts

PSA, %  Free

    • Because % free PSA is used to discriminate between cancer and benign disease, we are not using the NHANES population median for various ages and ethnicities as we did for Total PSA and Free PSA above.
    • Instead, we are using the evidence-based diagnostic thresholds derived from cancer detection studies.
    •  These thresholds apply across all ages and races for men with total PSA 2–10 ng/mL, based on the clinical literature.
      1. Optimal > 25% 
      2. Lab = 15%
      3. Alarm = 10%
    • The 25%, 15%, and 10% thresholds come from large prospective studies that compared % free PSA in men with biopsy-proven cancer vs. benign disease:
      1. Using a 25% cutoff, 95% of cancers were detected while avoiding 20% of unnecessary biopsies. At 15% specificity increased further.
        1. Catalona WJ, Partin AW, Slawin KM, et al. Use of the Percentage of Free Prostate-Specific Antigen to Enhance Differentiation of Prostate Cancer From Benign Prostatic Disease. A Prospective Multicenter Clinical Trial. JAMA. 1998;279(19):1542-1547. [PubMed]
      2. % free PSA <25%had a positive predictive value of 28% for cancer, while >25% had only 8% risk.
        1. Gann PH, Ma J, Catalona WJ, Stampfer MJ. Strategies combining total and percent free prostate specific antigen for detecting prostate cancer: a prospective evaluation. J Urol. 2002;167(6):2427-2434. [PubMed]
      3. % free PSA <10% had a 25-year prostate cancer mortality risk of 6.1%, compared to 1.1% for >25%.
        1. Wei JT, Barocas D, Carlsson S, et al. Early Detection of Prostate Cancer: AUA/SUO Guideline Part I: Prostate Cancer Screening. J Urol. 2023;210(1):46-53. [PubMed]