Disease treatment options and survival rates increase through early disease detection. A test measuring prostate-specific antigen (PSA) alerts your health care provider to the presence of prostate disease. Abnormal PSA levels may exist in a man experiencing no disease symptoms. Your health care provider may recommend the PSA test beginning when you are 40 and continuing "until you're at the age when your life expectancy is 10 years or fewer," according to the Mayo Clinic.
Definition
Prostate cells produce the protein prostate-specific antigen (PSA), secreting it into ducts in the prostate gland. PSA may also leak into the bloodstream. "Prostate cancer or benign (not cancerous) conditions can increase a man's PSA level," according to the National Cancer Institute. Blood drawn from a vein in the arm provides a sample for screening. The U.S. Food and Drug Administration approves the use of PSA testing as a tool to screen for prostate cancer.
Types
PSA bound to other proteins in the blood provides the level of PSA represented in the standard test. According to the American Cancer Society, a PSA level of 4.0 ng/ml or lower is considered safe. Borderline PSA levels range between 4.0 ng/ml and 10 ng/ml. A PSA level greater than 10 ng/ml represents elevated blood level of the antigen.
Free PSA ( PSA-f) circulates in the blood without binding to other proteins. PSA-f levels provide a secondary line of testing. Your health care provider may order this screening after the standard PSA test determines an elevated PSA level and before prostate biopsy. While standard PSA testing concerns itself with higher than normal levels, PSA-f testing concerns itself with lower than normal levels. The American Cancer Society reports a PSA-f level of 7 or lower indicates possible prostate disease.
Considerations
The confirmation of prostate disease may require multiple screenings of PSA level. According to the American Cancer Society, age, medications, other diseases processes, obesity and recent ejaculation may elevate PSA levels. Testing error represents the possibility of inaccurate PSA level reports. Abnormal PSA or PSA-f levels require close coordination between patient and doctor to determine a treatment course.
Other Uses
PSA screening provides data throughout a course of treatment. Health care providers may utilize the PSA and PSA-f test to determine cancer growth, evaluate treatment success, check on cancer re-occurrence, and determine further treatment options.
Limitations
Tumor classification, cancerous versus noncancerous and aggressive versus slow growing, require more in-depth screening than the PSA test offers. Physicians require this classification to determine appropriate treatment. According to the National Cancer Institute, researchers have not yet determined that PSA screening decreases a man's risk of dying from prostate disease.
