|
|
| A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # |
Prostate Health Index (phi), Serum
Test Code36372
CPT Codes
84153<br /> Limited Access Code
Includes
Free PSA and [-2] ProPSA testing are only performed when total PSA is 2-10 ng/mL
Preferred Specimen
1 mL serum collected in a red-top tube (no gel)
Patient Preparation
1.) Specimens for testing should be drawn prior to prostate manipulations such as digital rectal examination (DRE), prostatic massage, transrectal ultrasound (TRUS), and prostatic biopsy.
2.) Specimens should not be collected from patients receiving therapy with high biotin (vitamin B7) doses (ie, >5 mg/day) until at least 8 hours following the last biotin administration.
Minimum Volume
0.75 mL
Instructions
Prostatic biopsy is required for diagnosis of cancer.
Spin down within 3 hours of draw and separate serum from cells.
Spin down within 3 hours of draw and separate serum from cells.
Transport Container
Transport tube
Transport Temperature
Frozen
Specimen Stability
Room temperature: Not established
Refrigerated: Not established
Frozen: 5 months
Refrigerated: Not established
Frozen: 5 months
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Goss hemolysis • Serum Separator Tube (SST®) • Grossly icteric
Methodology
Enzyme Immunoassay (EIA)
Setup Schedule
Set up: Mon-Sat; Report available: 1 day
Reference Range
See Laboratory Report
Clinical Significance
Prostate-specific antigen (PSA) is a glycoprotein produced by the prostate gland, the lining of the urethra, and the bulbourethral gland. Normally, very little PSA is secreted in the blood. In conditions of increase glandular size and/or tissue damage, PSA is released into circulation. Measurement of serum PSA is useful for determining the extent of prostate cancer and assessing the response to prostate cancer treatment. PSA is also used as a screening tool for prostate cancer detection, although its use in screening has become controversial in recent years. While an elevated serum PSA is associated with prostate cancer, a number of benign conditions, such as benign prostatic hyperplasia (BPH) and prostatitis might lead to elevated serum PSA concentrations. As a consequence PSA lacks specificity for prostate cancer detection.
Several PSA isoforms have been identified that can further increase the specificity of PSA for prostate cancer. In particular, the [-2] form of proPSA (p2PSA) shows improved performance over either total or free PSA for prostate cancer detection on biopsy. The prostate health index (phi) is a formula that combines all 3 PSA forms (total PSA, free PSA, and p2PSA) into a single score. phi is calculated using the following formula: (p2PSA/free PSA) x square root (PSA).
In a multicenter study that compared the performance of PSA, free PSA, p2PSA, and phi in men undergoing prostate biopsy due to a serum PSA concentration between 4 and 10 ng/mL, phi was the best predictor of any prostate cancer, high-grade cancer, and clinically significant cancer. At 95% clinical sensitivity, the clinical specificity of phi was 16.0%, compared to 8.4% for free PSA and 6.5% for PSA.
Several PSA isoforms have been identified that can further increase the specificity of PSA for prostate cancer. In particular, the [-2] form of proPSA (p2PSA) shows improved performance over either total or free PSA for prostate cancer detection on biopsy. The prostate health index (phi) is a formula that combines all 3 PSA forms (total PSA, free PSA, and p2PSA) into a single score. phi is calculated using the following formula: (p2PSA/free PSA) x square root (PSA).
In a multicenter study that compared the performance of PSA, free PSA, p2PSA, and phi in men undergoing prostate biopsy due to a serum PSA concentration between 4 and 10 ng/mL, phi was the best predictor of any prostate cancer, high-grade cancer, and clinically significant cancer. At 95% clinical sensitivity, the clinical specificity of phi was 16.0%, compared to 8.4% for free PSA and 6.5% for PSA.
