PSA is a serine protease produced only in the prostate gland and, therefore, is an organ-specific marker. It is not cancer-specific however, as levels may also be elevated in benign conditions.

• Indications
  • Suspected prostate cancer
  • Monitoring for recurrence following treatment of prostate cancer
• Interpretation
  • Total PSA levels (I.e. free and bound PSA)
    • PSA > 4 ng/mL: Prostate cancer is likely.
  • Free PSA (unbound) : Free PSA levels are lower in prostate cancer than in normal prostate tissue or benign disease.
• Other causes of elevated total PSA: BPH, UTI, prostatitis, prostatic trauma or manipulation (including DRE)

Warning

A PSA level ≤ 4 ng/mL does not exclude prostate cancer!

Warning

5-alpha reductase inhibitors (5-ARIs) can suppress PSA production, resulting in spuriously low PSA levels. This should be taken into consideration in patients on long-term 5-ARIs (e.g., for BPH).

Tip

Inflammation, manipulation of the prostate, and other malignant and benign prostate diseases may lead to a false-positive PSA result!