Quick Facts
- Sample: Blood (serum)
- Fasting: No special preparation required. Avoid biotin-containing supplements for 12 hours before collection.
- Turnaround: 3-9 business days. May take longer based on weather, holiday, or lab delays.
What This Test Measures
This test measures Prostatic Acid Phosphatase (PAP) directly from a serum sample. PAP is an enzyme that has been used as a tumor marker since elevated levels were first observed in patients with metastatic prostate cancer.
When measured together with PSA, PAP can help your healthcare provider assess the prognosis of prostate malignancy and monitor how the disease and its treatment are progressing. Using both markers together can identify cases where PAP is elevated even though PSA is not, giving your provider a fuller picture. PAP is also noted to be more specific than PSA, with fewer false positive results linked to benign prostatic hyperplasia.
Benefits
- Measures PAP directly from a blood sample
- Supports prognosis assessment when used with PSA
- Helps monitor prostate cancer disease course over time
- Helps monitor response to prostate cancer treatment
- May identify elevated PAP when PSA is not elevated
- Associated with fewer false positives from benign prostatic hyperplasia
Who Is This Test For?
- People with a prostate cancer diagnosis whose provider is assessing prognosis
- People being monitored for prostate cancer disease progression
- People undergoing prostate cancer treatment whose response is being tracked
- People whose provider is using PAP alongside PSA for a fuller picture
- People whose healthcare provider has specifically recommended this test
How It Works
- Order Your Test Online
- Visit a Local Lab
- Get Results Online
FAQ
1. What is the purpose of this test?
This test measures Prostatic Acid Phosphatase (PAP) in serum. PAP is a tumor marker that, when evaluated alongside PSA, may help your healthcare provider assess the prognosis of prostate malignancy and monitor the course of the disease and its response to treatment. This test does not diagnose cancer on its own and is not a screening test.
2. Who would benefit from this test, and when should it be ordered?
This test may be considered for people who have been diagnosed with prostate cancer and whose healthcare provider wants to assess prognosis or monitor disease course and treatment response, particularly when used together with PSA testing. It does not replace clinical evaluation or provide a complete cancer assessment on its own. Your provider can help determine whether this test fits your specific situation and when it should be ordered.
3. How does this test differ from other cancer-related tests?
Unlike PSA alone, PAP measured alongside PSA may help identify cases where PAP is elevated but PSA is not, and PAP is noted to be more specific than PSA, with fewer false positives linked to benign prostatic hyperplasia. This test is not interchangeable with other cancer-related laboratory tests.
4. Do I need to fast before this test?
No special preparation is required for this test.
5. How quickly will I get results?
Results are typically available in 3-9 days. This may take longer based on weather, holidays, or lab delays.
6. How do I interpret the results?
Interpreting your PAP result depends on your specific value, your medical history, your clinical context, and other relevant findings, including PSA results. An elevated PAP level does not automatically establish a cancer diagnosis, and a normal result does not automatically rule out cancer. Because PAP is used alongside PSA to assess prognosis and monitor disease course, results are generally reviewed in that broader context rather than on their own. Your healthcare provider is best positioned to interpret your results.
Disclaimer: Reference ranges may vary by laboratory. Listed ranges are general guidelines and may differ from those used by the performing lab. Always consult your healthcare provider for interpretation.
7. What should I do if my results are abnormal?
Review abnormal results with a qualified healthcare provider, who can determine whether additional evaluation is appropriate based on your full clinical picture.
8. How often should I get tested?
How often you are tested should be determined by your healthcare provider, based on your individual situation and the purpose of monitoring your disease course or treatment response. Testing frequency should be discussed with your provider rather than following a fixed schedule.
Pre-test preparation
No special preparation is required for this test. Avoid biotin-containing supplements for 12 hours before collection.
