Free PSA pattern relative to BPH and PC?

• A. Normal in BPH and decreased in PC
• B. Elevated in BPH and normal in PC
• C. Decreased in BPH and elevated in PC
• D. Elevated in both BPH and PC

Answer: (A)

Free PSA is the portion of total PSA that is not bound to proteins in the blood. Its pattern helps distinguish benign from malignant prostate conditions. In BPH, the gland enlarges and PSA leaks into the serum in a relatively benign way, so the free fraction stays around its normal range (the percent free PSA is typically higher in BPH). In prostate cancer, more PSA is present in bound/complexed forms, so the free fraction drops and free PSA levels become decreased. Thus, a normal free PSA in BPH and a decreased free PSA in prostate cancer best describes the typical pattern. Clinically, a low percent free PSA supports cancer risk, while a higher percent free PSA leans toward benign disease.