The body produces prostate-specific antigen, also known as PSA, and it is normally present in low levels in the blood. A PSA test is a blood test used to determine if the levels of PSA in the blood are abnormally high. High levels of PSA can indicate the presence of prostate cancer.
Normal Levels
The result for a PSA test lists the amount of PSA present in the blood as nanograms of prostate-specific antigen per milliliter of blood. A PSA result of 4.0 ng/mL or higher warrants further testing. After a high PSA result, the next step is typically a biopsy. This determines if there are malignancies on the prostate or if the elevated PSA is due to enlargement or inflammation of the prostate gland.
Optional PSA Tests
The arbitrary cut-off level of the PSA test means that there are often false positives. A biopsy is an invasive procedure, so in order to prevent unnecessary discomfort for the patient, some doctors are refining the PSA tests. The percentage of PSA test determines the levels of free and attached PSA in the blood. A high level of free PSA indicates an increased risk of prostate cancer. The age adjusted PSA test uses a lower cut-off number for younger patients and a higher cut-off for older patients. It is natural for PSA levels to increase with age, even in a perfectly healthy individual. Adjusting the PSA levels by age may deliver results that are more reliable. A PSA velocity test measures any changes in the PSA levels over time. A dramatic increase in PSA levels may indicate cancer.
Digital Rectal Examination
Regardless of the type of PSA test conducted, it is not the only diagnostic test available. Doctors feel that both the PSA blood test and a digital rectal examination are important for prostate health. During a digital rectal examination, the doctor can palpate the prostate and determine if there are abnormal growths or it appears larger than average. The combination of a PSA blood test and a digital rectal examination determine if a prostate biopsy is recommended.
