PSA Testing: Pros and Cons
News Review From Harvard Medical School -- Panel Confirms Rejection of Routine PSA
An expert panel has stuck with its controversial advice that most older men should not get routine screening for prostate cancer. The U.S. Preventive Services Task Force said last fall that prostate-specific antigen (PSA) screening does more harm than good. A high test reading can indicate prostate cancer. But PSA can go up for other reasons. Only a biopsy can tell if cancer exists. Some prostate cancers can be deadly. But most grow so slowly they never cause harm. Men who get treated may have problems with sexual function and urine control. Urologists, who treat men with prostate cancer, protested the task force's statement last fall. But the panel was not persuaded. The advice issued May 21 said that there's little or no evidence that routine PSA tests save lives. The task force said men should be able to get a test if they want one. But first their doctors should explain the risks. The task force found that more research is needed on the benefits of PSA for men at highest risk of prostate cancer. These include black men and those with a family history of the disease. The Associated Press wrote about the issue.
By Howard LeWine, M.D.
Harvard Medical School
What Is the Doctor's Reaction?
Otherwise healthy men without any symptoms should stop having a routine PSA blood test to screen for prostate cancer. That's the final advice from the U.S. Preventive Services Task Force. This independent group of experts advises the government and doctors on preventive care practices.
Today most men 50 and over get this test as part of a regular checkup. It measures the amount of a protein called prostate-specific antigen. PSA is made by the prostate.
An above-normal PSA level can signal hidden prostate cancer. But PSA also rises for many other reasons. These include:
- An enlarged prostate
- A prostate infection
- After having sex or riding a bicycle
Even when prostate cancer causes a rise in PSA, most often that cancer would have otherwise gone unnoticed. Only a minority of prostate cancers harm a man's quality of life or shorten how long he lives.
The task force based its decision to say "no" to routine prostate cancer screening based on research. Studies have found that for every 1,000 men, routine PSA testing would:
- Prevent 0 to 1 deaths from prostate cancer
- Find 110 cases of prostate cancer (most of them unlikely to ever affect health or shorten life)
- Cause a heart attack, stroke, deep-vein thrombosis or pulmonary embolism in 3 men as a result of prostate cancer treatment
- Cause treatment-related erectile dysfunction (impotence) in 29 men
- Cause treatment-related loss of urine control (incontinence) in 18 men
As expected, many experts are already crying "foul" about the task force report. They say, "Yes, prostate cancer is usually slow growing. But not always. An estimated 28,000 American men will die from prostate cancer this year."
The expert task force has not ignored the fact that prostate cancer is the second leading cause of cancer death in men. (Lung cancer is No. 1, killing 87,000 American men yearly.) The problem is that we are not sure how many men PSA screening actually saves. The studies looking at this question have provided different answers. And we do know that PSA testing can lead to considerable harm.
So, on balance, the advice to not routinely screen men for prostate cancer makes sense. But this is a guideline. It does not dictate what patients and their doctors must do. It should be used to help them make informed decisions.
What Changes Can I Make Now?
If you are a man age 50 or older, should you stop having routine blood tests for PSA? Despite the task force advice, it's still your personal choice.
If you have an average risk of prostate cancer and overall good health, this is the way I approach the decision about PSA testing.
Ask yourself these questions before having your blood drawn for a PSA test.
- Are you willing to have a prostate biopsy if PSA testing shows that you might have prostate cancer?
- Would you want to get treatment right away if the biopsy showed any cancer cells, even very low-grade cancer cells that are unlikely to harm you? Would you get treatment even though it could leave you with erectile dysfunction, incontinence and possibly more severe problems?
My personal answer to question No. 1 is "no." I do not get PSA tests.
But here is how I advise my patients who answer "yes" to question No. 1.
If you also answer "yes" to question No. 2, then getting a PSA test is a reasonable choice for you.
If you answer "yes" to question No. 1 and "no" or "not sure" to question No. 2, then you need to ask yourself:
- Would you be comfortable with frequent monitoring but no treatment, if the biopsy shows only low-grade prostate cancer? (Monitoring would include regular PSA blood tests and perhaps repeat prostate biopsies.)
This last question is not so straightforward. It is not a simple "yes" or "no." For example, you probably would want prostate cancer treatment right away if the biopsy showed more aggressive prostate cancer. But you might feel very uncomfortable if you had low-grade prostate cancer cells that were just being watched.
What Can I Expect Looking to the Future?
Scientists are actively looking for a better test than PSA to screen for prostate cancer. But we don't necessarily have to give up on the PSA. The problem of prostate cancer overtreatment is not the PSA test. It is more related to the mistaken idea that catching every cancer early saves lives.
A PSA that stays high or goes up might still lead to a biopsy. But there are some abnormal prostate cells that will cause no harm. If we called those cells something else besides cancer, men could be more comfortable not rushing to get treatment they don't need.