Prostate Specific Antigen, Free Percentage (Includes Free PSA and Total PSA)

The Roche PSA electrochemiluminescent immunoassay is used. Results obtained with different assay methods or kits cannot be used interchangeably. The Roche PSA method is approved for use as an aid in the detection of prostate cancer when used in conjunction with a digital rectal exam in individuals with a prostate age 50 years and older. The Roche Modular E170 PSA method is also indicated for the serial measurement of PSA to aid in the prognosis and management of prostate cancer patients. Elevated PSA concentrations can only suggest the presence of prostate cancer until biopsy is performed. PSA concentrations can also be elevated in benign prostatic hyperplasia or inflammatory conditions of the prostate. PSA is generally not elevated in healthy individuals or individuals with nonprostatic carcinoma.
                                                                                    
ARUP uses the Roche Free PSA electrochemiluminescent immunoassay method in conjunction with the Roche PSA electrochemiluminescent immunoassay method to determine the free PSA percentage. The free PSA percentage is an aid in distinguishing prostate cancer from benign prostatic conditions in individuals with a prostate age 50 years and older with a total PSA between 3 and 10 ng/mL and negative digital rectal examination findings. Prostatic biopsy is required for the diagnosis of cancer. (Refer to: JAMA, 1998;279:1542-1547)