Why we measure it

PSA is one of the most studied blood markers in men's health. Prostate cancer is the most commonly diagnosed cancer in men, and research on PSA testing has shaped guidelines for decades. The largest trial, the European Randomised Study of Screening for Prostate Cancer (ERSPC), enrolled 182,000 men across seven European countries; at 16 years it reported a 21% reduction in prostate cancer mortality in the group offered PSA testing, and 27% among those who attended. The USPSTF's 2018 update recommends that men aged 55–69 make an individual decision about PSA testing with their clinician, weighing that benefit against the risks of overdiagnosis and overtreatment. The Blueprint Bloodwork protocol measures PSA annually from 40 for a specific reason: research shows the rate of rise over time (PSA velocity) adds information beyond any single level. Years of readings build a personal baseline before age-related prostate enlargement (BPH) muddies the signal, so a later change is far easier for a physician to interpret than a first-ever reading of 4.2 ng/mL at 58. PSA is not diagnostic on its own.

Why every 12 months

Prostate cancer, in most cases, grows slowly — PSA tends to rise over years rather than months, which is exactly why annual measurement is appropriate rather than more frequent testing. Annual draws provide the time resolution to calculate PSA velocity meaningfully: a rise of more than 0.75 ng/mL per year in men with PSA above 4.0 ng/mL, or more than 0.4 ng/mL per year in men with PSA below 4.0 ng/mL, has been shown in prospective studies to independently predict prostate cancer and, specifically, to predict fatal prostate cancer decades before diagnosis. This velocity signal — which requires serial annual measurements to compute — is a key reason why the protocol begins testing at 40 rather than 50 or 55.

What movement means

The historically used clinical threshold of 4.0 ng/mL to trigger biopsy has been substantially revised by the research literature. A landmark study by Thompson et al., published in the New England Journal of Medicine (2004), found prostate cancer in 15% of men with PSA below 4.0 ng/mL who were biopsied — and high-grade cancer (Gleason score ≥ 7) in 2.3% of men with PSA below 1.0 ng/mL. Cancer exists across the full PSA range. What the absolute PSA level does predict is cancer risk: risk increases continuously with PSA, with cancer found in approximately 10% of men with PSA 2.0–4.0 ng/mL, 25% of men with PSA 4.0–10.0 ng/mL, and more than 50% of men with PSA above 10.0 ng/mL. The ranges below describe relative risk categories based on this evidence — not diagnostic thresholds. The absolute PSA level is one input; PSA velocity, free:total PSA ratio, age, and clinical context together determine the appropriate next step.

This page summarises published research for general education. It is not medical advice and does not interpret individual results. Discuss your results with a registered medical practitioner.

In the protocol