The Devil You Know? Or The One You Do not Know?
13 Nov 2011
Lately many of the e-mails I’ve received have been from men. Why?” Because a panel of U.S. experts recently reported that healthy men should say “No” to the PSA test that diagnoses prostate cancer. To many this is like damning motherhood and apple pie as thousands of men routinely get this test every year.
Several cancer specialists in Canada have openly criticized this report. They argue that the PSA test, although not perfect, does save lives. But the U.S. panel claims it has no significant effect on the number of deaths, and often the end result is serious complications from treatment. So who is right?
This problem is like asking “How may angels can dance on the head of a pin?” None of us knows the answer. And no one knows the definitive answer to the dilemma of prostate cancer. So what do we know for sure about the PSA test?
The PSA test measures the level in the blood of a protein produced by the prostate gland. But the test is not specific for cancer as three out of four men with increased PSA levels do not have malignancy. Rather, it’s due to either an enlargement of the gland, inflammation or infection.
There’s even debate about at what level the PSA is able to detect prostate cancer. The accepted level has been 4.1. But several years ago a report in the New England Journal of Medicine claimed that this value misses 15 percent of prostate malignancies. Then a study at the University of Texas showed that 6.6 percent of men with a PSA level of 0.5 had prostate cancer! It appears no level is totally safe.
What worries the U.S. panel is that an increased PSA level sets in motion a series of events that often cause more harm than good. For instance, to determine if a cancer is present several biopsies of the prostate gland must be done. And if cancer is discovered should it always be treated?
Evidence of prostate cancer is like graying hair. Autopsies show that by age 70 about 50 percent of men have microscopic cancer in the gland. If it’s a slow growing cancer it may take 15 years to cause death. In the meantime death may occur from other causes. Or as the late Dr. Willet Whitmore, a world authority on prostate cancer, remarked, “ Growing older is invariably fatal, cancer of the prostate only sometimes.”
But does the test save lives? Most authorities would say yes, but they question the number. For instance, the New England Journal of Medicine reported a European study that followed 162,000 men for 10 years. Of those who had the test 363 died. But of those given the test 261 still died. A difference of 102 deaths out of 162,000 men isn’t terribly impressive.
Another study showed that 1,419 men would have to be screened by the PSA test and an additional 48 men treated, to prevent one cancer death. This modest effect on mortality has to be offset by the complications of those treated for this malignancy.
So here is the great dilemma. The PSA test saves a few lives, but it can also result in severe complications from surgery or other therapies. Being a medical journalist makes me more aware of this fact than others as I receive considerable feed-back from readers. Many have said, “If I’d known I’d be in diapers the rest of my life or impotent I would never have agreed to the treatment”. So in some cases, particularly elderly men, it’s better to live with the devil you know than the one you’ve never met.
I also believe complications are underreported. A patient with urinary incontinence is much more aware of the annoyance than the surgeon who performs the operation.
So one needs the Wisdom of Solomon, which I don’t have, to know whether it’s prudent to have surgery or other therapies if prostate cancer is diagnosed.
So should you have a PSA test? I wish I had the answer for you. In the end only you and your doctor can make that important decision.
