The prostate-specific antigen test is a blood test that measures levels of a protein the prostate gland produces. Men with prostate cancer usually have elevated levels of this protein, but heightened levels do not always mean cancer.
Other health conditions may also cause prostate-specific antigen (PSA) levels to rise. In some cases, an elevated PSA is temporary and not a sign of a health problem at all.
Cells in the prostate gland produce PSA and levels typically remain below 4 nanograms per milliliter (ng/mL).
Most men with prostate cancer have PSA levels above 4 ng/mL, but about 15 percent of men with a PSA level below 4 ng/mL are also diagnosed with prostate cancer. This means that a PSA test alone cannot rule out or diagnose prostate cancer but can identify whether a man is at higher risk of having or developing the disease.
Initial testing may include both a PSA test and a digital rectal exam (DRE). During this examination, a doctor inserts a finger into the rectum to check the prostate for abnormalities. Together, if these two tests suggest prostate cancer, then the doctor will arrange for a biopsy to confirm the diagnosis.
False positives - a high PSA level, but no cancer - on the PSA test are common. PSA levels rise with age and other factors. Men with high PSA levels should follow up with a doctor, but should not assume they have cancer.
 |
| A high PSA level may not always indicate prostate cancer. |
