Test Code LAB3444 Prostate Health Index Reflex, Serum
Specimen Required
Patient Preparation:
1. Specimens for testing should be collected prior to prostate manipulations such as digital rectal examination, prostatic massage, transrectal ultrasound, and prostatic biopsy.
2. A 6-week waiting period between needle biopsy and specimen collection is recommended.
3. 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.
Supplies: Sarstedt Aliquot Tube 5 mL (T914)
Collection Container/Tube: Red top (serum gel/SST are not acceptable)
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions: Within 3 hours of collection, centrifuge, aliquot serum into a plastic vial, and refrigerate. Freeze sample within 24 hours of collection and send frozen.
Secondary ID
113000Useful For
As an aid in distinguishing prostate cancer from benign prostatic conditions in men aged 50 years and older with total PSA between 4.0 and 10.0 ng/mL and digital rectal examination findings that are not suspicious for cancer
Reflex Tests
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
PHI13 | Prostate Health Index (phi) Reflex | No | No |
Testing Algorithm
This test begins with the analysis of prostate-specific antigen (PSA). If the PSA concentration is between 2.0 and 10.0 ng/mL, then the reflex test will be performed at an additional charge.
If the initial PSA concentration is between 2.0 and 10.0 ng/mL, then free PSA and [-2]pro-PSA isoform results will be reported.
If the initial PSA concentration is between 4.0 and 10.0 ng/mL, then the percent free PSA result and prostate health index (phi) will be calculated and reported.
If the initial PSA concentration is between 2.0 and 4.0 ng/mL, then the percent free PSA result and prostate health index (phi) will not be calculated or reported.
Method Name
Immunoenzymatic Assay
Reporting Name
Prostate Health Index Reflex, SSpecimen Type
Serum RedSpecimen Minimum Volume
0.75 mL
Specimen Stability Information
Specimen Type | Temperature | Time |
---|---|---|
Serum Red | Frozen (preferred) | 150 days |
Ambient | 24 hours | |
Refrigerated | 24 hours |
Reject Due To
Gross hemolysis | Reject |
Gross icterus | Reject |
Reference Values
Females: Not applicable
PROSTATE-SPECIFIC ANTIGEN (PSA) MALES:
Age |
Reference range |
<40 years |
≤2.0 ng/mL |
40-49 years |
≤2.5 ng/mL |
50-59 years |
≤3.5 ng/mL |
60-69 years |
≤4.5 ng/mL |
70-79 years |
≤6.5 ng/mL |
≥80 years |
≤7.2 ng/mL |
PERCENT FREE PSA MALES:
When PSA is in the range of 4.0-10.0 ng/mL
% Free PSA |
Probability of cancer |
≤10% |
56% |
11-15% |
28% |
16-20% |
20% |
21-25% |
16% |
>25% |
8% |
PROSTATE HEALTH INDEX (phi) MALES:
When PSA is in the range of 4.0-10.0 ng/mL
phi range |
Probability of cancer |
95% Confidence interval |
0-26.9 |
9.8% |
5.2-15.4% |
27.0-35.9 |
16.8% |
11.3-22.2% |
36.0-54.9 |
33.3% |
26.8-39.9% |
≥55.0 |
50.1% |
39.8-61.0% |
Cautions
Specimens for [-2]pro-prostate-specific antigen (p2PSA) testing should be collected prior to prostate manipulations such as digital rectal examination (DRE), prostatic massage, transrectal ultrasound, and prostatic biopsy. DRE may cause a transient increase in p2PSA, free prostate-specific antigen (PSA), and PSA.
Transrectal needle biopsy has also been shown to cause transient increases in p2PSA, free PSA, and PSA elevations, thus a 6-week waiting period between needle biopsy and p2PSA, free PSA, and PSA sampling is recommended.
The prostate health index (phi) results should be interpreted in light of the total clinical presentation of the patient, including symptoms, clinical history, data from additional tests, and other appropriate information. The phi should not be interpreted as absolute evidence for the presence or absence of prostate cancer. Elevated PSA concentrations, increased phi, or decreased free PSA may be observed in patients with nonmalignant disorders, as well as those with prostate cancer.
Routine use of 5 alpha-reductase inhibitor drugs typically lower PSA, free PSA, and p2PSA levels in patients. Other drugs used to treat benign prostatic hyperplasia may also affect PSA levels. Care should be taken in interpreting results from patients taking these drugs.
For patient samples containing elevated levels of total protein (>8 g/dL), the possibility exists for interference by total protein. Carefully evaluate the results of patients suspected of having elevated total protein levels.
Free PSA specimens can potentially be falsely decreased by biotin. Biotin should not strongly affect total PSA or p2PSA values.
In rare cases, some individuals can develop antibodies to mouse or other animal antibodies (often referred to as human anti-mouse antibodies (HAMA) or heterophile antibodies), which may cause interference in some immunoassays. Caution should be used in interpretation of results and the laboratory should be alerted if the result does not correlate with the clinical presentation.
The use of the prostate health index (phi) has not been validated when PSA values are outside of the range of 4.0 to 10.0 ng/mL
Day(s) Performed
Monday through Saturday
Report Available
1 to 3 daysPerforming Laboratory

Test Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
84153 - Total PSA
84154 - Free PSA (if appropriate)
86316 - [-2]ProPSA (if appropriate)
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
PHI11 | Prostate Health Index Reflex, S | 53764-7 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
PHI12 | Prostate Specific Antigen, S | 83112-3 |
NY State Approved
YesForms
If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.