PSA Levels and Prostate Cancer
This is the VOA Special English HEALTH REPORT.
Many older men are tested each year for cancer of the prostate gland. This organ is part of the male reproductive system. One test measures levels in the blood of a protein known as P.S.A. P.S.A. is prostate-specific antigen. Most men with prostate cancer have increased levels of this protein.
The test results come back from the laboratory as a number. Doctors usually consider the results normal if the P.S.A. level is below four. But a new study raises questions. The study found prostate cancer in fifteen percent of older men with P.S.A. levels below four. But the researchers also found that most of these cancers were not especially dangerous. The risk of prostate cancer increased as the P.S.A. levels got higher.
A result above ten is considered high. But a high P.S.A. level does not always mean that a man has cancer. There could be an infection or an enlarged prostate. This is a common problem in older men.
The study involved almost three-thousand men. They were ages sixty-two to ninety-one. Ian Thompson of the Texas Health Science Center at San Antonio led the study. The results appeared in the New England Journal of Medicine.
Doctors often perform biopsies on men with increased P.S.A. levels. They cut a small amount of tissue from the prostate to look for cancer. If cancer is found, then the question arises of what to do next.
Doctors must decide how aggressive the cancer is. Non-aggressive prostate cancers usually grow slowly. They do not normally spread to other organs.
Researchers say almost thirty percent of men in their thirties and forties have prostate cancer but do not know it. By their sixties and seventies, however, two out of three men may have prostate cancer.
Some doctors advise men with non-aggressive prostate cancer to delay treatment. But, in the United States, almost thirty-thousand men per year die of prostate cancer. So most patients elect to have treatment. This often means an operation to remove the prostate.
Last December, Secretary of State Colin Powell had an operation in which doctors removed his prostate because of cancer. Senator John Kerry, the Democratic presidential candidate, had the same experience early last year.
This VOA Special English HEALTH REPORT was written by Jerilyn Watson.