Total PSA w/ Reflex to Free PSA
Test Overview
The Total PSA with Reflex to Free PSA test measures the level of Prostate-Specific Antigen (PSA) in the blood, which is a protein produced by the prostate gland. PSA levels can be elevated in various conditions, including prostate cancer, benign prostatic hyperplasia (BPH), and prostatitis. The total PSA test measures both bound and unbound PSA in the blood. If the total PSA levels are elevated, the test reflexively measures free PSA, which is the unbound portion of the PSA. The ratio of free PSA to total PSA can help distinguish between prostate cancer and benign prostate conditions, as lower free PSA ratios are more commonly associated with prostate cancer.
Test Types
- Total PSA Test: Measures the total amount of PSA (bound and free) in the blood.
- Free PSA Test: Measures the unbound portion of PSA, which helps assess the likelihood of prostate cancer.
- PSA Ratio (Free PSA/Total PSA): The ratio of free PSA to total PSA, used to help differentiate between prostate cancer and benign conditions.
Total PSA with Reflex to Free PSA Test Results & Ranges
| Test Component: | Normal Range: | Abnormal (Possible Conditions): |
|---|---|---|
| Total PSA | 0–4.0 ng/mL | High: Prostate Cancer, Benign Prostatic Hyperplasia (BPH), Prostatitis |
| Free PSA | 10–25% of total PSA | Lower free PSA percentages (<10%) suggest a higher risk for prostate cancer |
| PSA Ratio (Free PSA/Total PSA) | >25% | A lower ratio (≤10%) indicates a higher likelihood of prostate cancer |
Expected Turnaround Time
- Results Available: 1–2 business days
Specimen Requirements
- Sample Type: Blood sample (venipuncture)
- Container: Serum separator tube (SST) or plain tube
Collection Instructions
- Fasting is not required, but some laboratories may suggest fasting to standardize results.
- Avoid ejaculation for 24–48 hours before the test, as this can temporarily raise PSA levels.
- Avoid recent prostate procedures (such as digital rectal exams, prostate biopsy, or cystoscopy) as these can elevate PSA levels.
- Inform your healthcare provider of medications (e.g., finasteride, dutasteride) as they can lower PSA levels.
- Storage: Blood samples should be processed promptly and stored according to lab protocols, typically refrigerated or at room temperature until testing.
Test Details
Clinical Use: Evaluates prostate health: The Total PSA test is used as a screening tool for prostate cancer in men, especially those over the age of 50 or with a family history of the disease. Distinguishes between benign and malignant conditions: If the total PSA level is elevated, the Free PSA test helps determine the likelihood that prostate cancer is present. Lower free PSA ratios suggest that prostate cancer may be more likely. Monitors treatment: PSA testing is also used to monitor patients with prostate cancer who are undergoing treatment such as surgery or radiation therapy. Assesses risk for prostate cancer: The Free PSA percentage can be used to assess whether further diagnostic testing (like a prostate biopsy) is needed.
Limitations: PSA levels can be affected by various factors, including age, prostate enlargement (BPH), prostatitis, recent sexual activity, and certain medications. PSA testing may not be specific to prostate cancer, as elevated levels can also be caused by benign conditions. False positives and false negatives can occur, so PSA testing is often combined with other diagnostic tests (e.g., digital rectal exam, biopsy, imaging). Free PSA testing is primarily used to evaluate the risk of prostate cancer in men with mildly elevated PSA levels.
The Total PSA with Reflex to Free PSA Test is a valuable tool for prostate cancer screening, distinguishing between benign and malignant prostate conditions, and monitoring prostate health.