PSA Levels Indicating Metastasis of Prostate Cancer

Correlation Between PSA Levels and Metastatic Risk

• PSA levels of 20 ng/mL or higher significantly increase the risk of metastatic prostate cancer, though metastasis can occasionally occur with lower PSA values, particularly in high-grade or atypical histologic variants 1, 2, 3
• The American Urological Association suggests that PSA levels correlate with the probability of metastatic disease:
• The proportion of men with pathologically organ-confined disease decreases as PSA increases:

Imaging Recommendations Based on PSA Levels

• The American College of Radiology recommends that bone scans are generally not necessary in patients with newly diagnosed prostate cancer who have a PSA < 20.0 ng/mL unless:
• CT or MRI staging is generally unnecessary if PSA is < 25.0 ng/mL, but may be considered when:

Special Considerations

• PSA velocity (PSAV) is also associated with metastatic risk:

Practical Algorithm for Metastatic Evaluation

• For PSA < 10 ng/mL, consider bone scan only if:
• For PSA 10-20 ng/mL, bone scan recommended, especially with higher Gleason scores 1, 2
• For PSA > 20 ng/mL, bone scan strongly recommended, and consider CT/MRI for nodal staging 1, 2, 3

Caveats and Pitfalls

• PSA alone should not be the sole determinant for metastatic evaluation; consider: