The Prostate-Specific Antigen, PSA test, for prostate cancer

There are many men like my self over 50 years of age. However, only a small percentage of us will take this potential life saver any time soon. The mentality of, "if I go to the Doctor, then he'll find something wrong!", is played out. Men need to start being more preventive, as our female counter-parts are, in early intervention wellness. The Antigen exam would certainly be a step in the right direction. Although this test does not automatically condemn a man, it may save his life.

The Science Behind Prostate Specific Antigen

Prostate specific antigen is a substance made by the prostate gland. Although the substance is mostly found in semen, a small amount is also present in the blood. According to the American Cancer Society, most men have levels under 4 nanograms per milliliter of blood (ng/ml). When prostate cancer develops, the PSA level usually goes above 4ng/ml but in some cases, the cancer can be present at levels lower than 4. A PSA rise does not automatically mean cancer. PSA also rises when the prostate is enlarged because of benign prostatic hyperplasia, or BPH, and sometimes with prostatitis.

If the level is borderline range between 4ng/ml and 10ng/ml, a man has about a 25 percent to 35 percent chance of having prostate cancer. PSA higher than 10ng/ml could mean between a 40 percent and 50 percent chance for cancer, and the risk increases further as the PSA level increases. PSA is an ideal marker for prostate cancer because it is basically restricted to prostate cells.

Most PSA tests measure "total PSA," or the amount that is bound to blood proteins. But some tests measure not only total PSA, but another component called free PSA, which floats unbound in the blood. Free PSA above 25 percent is a stronger indication that cancer is not present. Comparing the two helps doctors rule out cancer in men whose PSA is mildly elevated from other causes.

The benefits of screening for prostate cancer are still being studied. Scientists are researching ways to distinguish between cancerous and noncancerous conditions, those that are slow-growing and fast-growing, and potentially lethal cancers through new PSA methods and other tumor markers.

The National Cancer Insitute and other medical organizations are conducting the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, or PLCO Trial, to determine whether certain screening tests reduce the number of deaths from these cancers. The PSA and DRE tests are being studied to see whether yearly screening will decrease a man's chance of dying from prostate cancer. See Medlineplus for additional information

PSA test