Percent Complexed PSA (Includes Total PSA)
Specimen Collection Criteria
The Complexed PSA assay (cPSA) is no longer being performed in the Automated Chemistry Laboratory and has been replaced with the Free PSA (fPSA). When a Free PSA (fPSA) test is ordered, the report will include:
When total PSA is in the range of 2.5 to 10 ng/mL, the percent (%) Free PSA gives an estimate of the probability of cancer. A % Free PSA of < = 10% indicates a 49% to 65% risk of prostate cancer, depending on age; a % Free PSA of > 25% indicates a 9% to 16% risk of prostate cancer, depending on age (JAMA 1998; 279: 1542 – 1547).
In these circumstances the measurement of % Free PSA may aid in avoiding unnecessary biopsies. The ultimate decision to perform prostate biopsy should be made between the patient and clinician, based on all relevant clinical and laboratory findings.
Centrifuged SST tubes may be transported
and stored at room temperature (up to 25oC or 77oF)
for 2-4 hours. DO NOT FREEZE TUBES CONTAINING WHOLE BLOOD. For longer storage,
the specimen should be refrigerated (2o-8oC).
Red-top tubes may be stored at room temperature for up to 2 hours.
DO NOT FREEZE TUBES CONTAINING WHOLE BLOOD. For longer storage, the serum
should be removed from the clot and refrigerated (2o-8oC).
Automated Chemistry Laboratory – RO
Microtainer® and Vacutainer® are registered trademarks of Becton, Dickinson and Company.
UroVysion® is a registered trademark of Abbott Laboratories. ThinPrep® is a registered trademark of Hologic, Incorporated.
This directory currently reflects information only for specimens collected and/or processed at the
Farmington Hills, Grosse Pointe, Royal Oak, and Troy campuses.