Prostate-specific antigen (PSA) Test
What is a PSA Test?
The prostate-specific antigen test or the PSA is recommended to confirm the possibility of prostate cancer. This simple blood test looks for the levels of gamma-seminoprotein or prostate-specific antigen as it is more commonly known. Though this antigen exists in all men, raised levels indicate the presence of various prostate disorders.
Why is it conducted?
Though considered to be a test to detect cancer, increased level does not necessarily point towards cancerous growth. Increase in levels can be due to non cancerous growths, irritation, enlargement of the prostate or inflammation.
Who should go for it?
Earlier, this test was advised for routine screening of older men to detect cancer at an early stage. However, considering the fact that except for a few cases prostate cancer is a very slow growing cancer and aggressive treatment may lead to more damage than the cancer itself, the decision to go for a PSA test should always be taken after careful consideration only. It is worthwhile to have this test under the following circumstances:
- Persons who have a family history of prostate cancer.
- If any abnormality is observed during a physical exam, then this test is recommended.
- Persons who have been diagnosed with prostate cancer may have this test for staging of the cancer.
- Persons who are undergoing treatment for prostate cancer may have this test to check for response to treatment.
- People who had prostate cancer previously may have this test to check for recurrence. For those whose prostate has been removed, PSA levels should be negligent or entirely absent.
This is a simple blood test. It should not be done during a UTI as it can influence levels of PSA in the blood.
Interpretation of results
This test should always be followed by biopsy if cancer is suspected. Further testing is needed to ascertain the cause of higher than normal levels of PSA in the bloodstream. The possibility of a false- positive or the growth being non-cancerous should always be kept in mind. It is important to remember that even ejaculation up to 48 hours before the test can raise the levels of this antigen. PSA levels can be high due to other disorders of the prostate, a recent DRE (digital rectal examination) or a catheter for draining urine. Medicines that are used for cancer treatment or enlarged prostate also affect PSA levels. In some cases, the prostate-specific antigen may fail to rise even when there is a cancerous growth. A factor that lowers PSA is obesity.
- Normal range is 4.0 ng/mL or less than this, but results always need to be interpreted with other factors, especially age.
- Normal levels are 2.5 ng/mL, for below 49 years.
- Normal levels are 3.5 ng/mL, for below 59 years.
- Normal levels are 4.5 ng/mL, for below 69 years.
PSA Levels at or above 8.0 ng/mL need to be investigated further. If there is a continual rise in the levels, then the chances of cancer are higher. Besides this, in general, remarkable increase in PSA levels also point towards prostate cancer. For persons with high PSA levels it is worthwhile to have a test for free PSA levels in the blood before contemplating a biopsy for confirmation. An important consideration is the fact that prostate cancer is generally not very aggressive and does not affect life expectancy. However, the decision to go ahead for cancer treatment is best taken after analyzing the degree of risk.
Written by: healthplus24.com team
Date last updated: January 09, 2015