Dear Source:
We must be careful as we approach screening for prostate cancer. Prostate cancer is the leading cause of cancer in men. However, it is not necessarily the number one cause of cancer-related death in men. This is because some forms of prostate cancer are slow growing and a man may very well die of other causes before dying of prostate cancer.
Various medical societies have varying recommendations on when to begin prostate screening because there is no clear consensus as to the best way to detect prostate cancer most effectively. The problem seems to lie at various levels. First, the PSA blood test is not a perfect test. It may have false-positive results where the test comes back abnormal but there is no prostate cancer. It also can have false-negative results where the test comes back normal but there is prostate cancer. Additionally, the digital rectal exam (DRE) is also somewhat subjective and not a perfect test.
The basic purpose of health screening is to detect conditions that 1) do not have symptoms, 2) are common, 3) are treatable, and 4) can shorten a patient's life if not treated. In the case of prostate cancer, it is an asymptomatic and common disease. However, there is a difference of opinion regarding what may be the best treatment of a particular stage/form of prostate cancer. Additionally, the treatment of prostate cancer can have side effects, which can include impotence (what most men worry about). Finally, there is a lack of consensus as to if treatment will lead to a longer life.
For example, if an 83 year-old man who has diabetes, high blood pressure, and a history of a stroke is screened for prostate cancer and found to have an abnormal PSA, what should the treatment be? Statistically, this man will most likely die of cardiovascular disease before he dies of prostate cancer. The question then lies: does this patient undergo biopsy, surgery, chemotherapy, radiation therapy?
Another consideration is the possible effect of the false-positive and false-negative scenarios. If a 50 year-old man is found to have an abnormal PSA, he will most likely undergo prostatic biopsy, which may have side effects, and possible surgery, which can also have side effects. He may, indeed, not even have prostate cancer. He may also have undiscovered diabetes, hypertension, or colon cancer, which may end his life before his prostate cancer does.
All this being said, it is important to undergo recommended routine health screening. Screening should not take place in a vacuum. Ideally, all men and women should have a primary health care provider who can explain what is recommended and the best way to go about it. Pretty much all medical organizations recommend that health care providers discuss any screening tests with their patients before that particular screening takes place.
Joseph DeJames, M.D.
St. John
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