Prostate-Specific Antigen (PSA), Free:Total Ratio
Fasting Required: No

Specimen: Blood

Results: 2-3 Business Days

Description:
Most PSA tests measure "total PSA," or the amount that is bound to blood proteins. In March, FDA approved the Tandem R test, which measures not only total PSA but another component called "free PSA," which floats unbound in the blood. Comparing the two helps doctors rule out cancer in men whose PSA is mildly elevated from other causes. A 1995 study in the Journal of the American Medical Association showed that the free PSA test can reduce unnecessary prostate biopsies by 20 percent in patients with a PSA between 4 and 10.

Includes:
Total PSA, Free PSA, % Free PSA (calculated)

Methodology:
Immunoassay (IA)

Limitations:
Based on solid evidence, screening with PSA and/or DRE detects some prostate cancers that would never have caused important clinical problems. Current prostate cancer treatments, including radical prostatectomy and radiation therapy, result in permanent side effects in many men. The most common of these side effects are erectile dysfunction and urinary incontinence. Whatever the screening modality, the screening process itself can lead to adverse psychological effects in men who have a prostate biopsy but do not have identified prostate cancer. Prostatic biopsies are associated with complications, including fever, pain, hematospermia/hematuria, positive urine cultures, and rarely sepsis.

Reference Range(s):
Total PSA =4.0 ng/mL
% Free PSA >25 % (calc)

Clinical Significance:
In men over 50 years with total PSA between 4.0 and 10.0 ng/mL, the percent (%) free PSA gives an estimate of the probability of cancer. In these circumstances the measurement of the % free PSA may aid in avoiding unnecessary biopsies.

Elevated levels of Prostate Specific Antigen (PSA) have been associated with benign and malignant prostatic disorders. Studies indicate that in men 50 years or older measurement of PSA is a useful addition to the digital rectal exam in the early detection of prostate cancer. In addition, PSA decreases to undetectable levels following complete resection of the tumor and may rise again with recurrent disease or persist with residual disease. Thus, PSA levels may be of assistance in the management of prostate cancer patients.

Alternative Name(s):
Fractionated PSA,Prostate Specific Antigen Free and Total,PSA, Free,Free PSA and Total PSA,PSA II

Note: Result turn around times are an estimate and are not guaranteed. Our reference lab may need additional time due to weather, holidays, confirmation/repeat testing, or equipment maintenance.