Prostate specific antigen (PSA) is a protein produced by the prostate gland that can be measured in the blood. PSA levels are often used to screen for prostate cancer. There are many conditions that can cause the PSA level to rise above the normal level of 4 -- for example, a chronic prostate infection or benign enlargement of the gland -- but once the PSA level goes above 10, the likelihood of prostate cancer increases dramatically. Furthermore, a rapidly rising PSA level can be an ominous sign of an aggressive form of the disease.
In most men, an elevated or rising PSA level deserves further evaluation. Usually this begins with a needle biopsy of the prostate gland. If there is evidence of cancer, additional tests may help to determine whether and where the cancer has spread. Typical tests include a bone scan, CT or MRI scan of the pelvis, and a chest X-ray.
However, doctors sometimes recommend simply following a rising PSA level without ordering additional tests. This is particularly true in older men, since prostate cancer can be a slow-growing disease that causes few symptoms and little harm. For example, many more men die with prostate cancer than from prostate cancer. There is also some concern that aggressive treatment of prostate cancer can do more harm than good, especially in older men who may have many other medical conditions and a limited life expectancy.
That said, prostate cancer can cause a variety of problems including severe pain in the bones, blockage of the bladder, and damage to the spinal cord. A man with an elevated PSA level who experiences any of these symptoms should seek urgent medical attention.
