First, a disclosure: I used to work with the U.S. Preventive Services Task Force, and I was the editor of the group's first book, 20 years ago. But I want to talk mainly about the issues behind this prostate cancer screening recommendation, not whether it's right or wrong.
It's important to remember that preventive medicine is optional. When patients come into the office bleeding or doubled over in pain, we don't have a choice of whether to treat them or not. We do the best we can, using whatever information and evidence is available to guide our care. But that's not the way it is in preventive medicine. We want strong evidence.
Because when you are asking asymptomatic people to come into your office, making them or their insurance company pay for a screening test and exposing them to possible side effects, you'd better be clear that what you're doing has been proven to help them.
So — how do you decide whether to get a screening test?
First, you have to know something about the disease you're screening for. It needs to be an important, relatively common and serious disease. We don't screen people for ingrown toenails. But it also helps if the disease has a long asymptomatic phase, when a screening test could find it early: If you get a disease and it's immediately fatal, a screening test won't be of any use.
Screening tests all have risks associated with them: side effects, costs, false positives and so forth. So you need one that's cheap, accurate and has acceptable side effects.
But most importantly, screening tests must have proven benefits: They have to identify a disease that we can actually do something about that makes a difference in health outcomes. And the benefits have to outweigh the harms related both to screening and treatment.
So where does this leave us with prostate cancer screening? Is it a serious, common disease? Absolutely. More than 28,000 American men will die from prostate cancer this year. Does it progress slowly with a long asymptomatic phase? Yes, it does. Do we have an accurate screening test for it? Well, the blood test called PSA, prostate-specific antigen, is inexpensive and pretty accurate. Its levels do go up with most prostate cancers, although other, more benign things can elevate it, too.
But what about the proven benefits of PSA screening? Do they outweigh the harms? This is the problem. There just aren't any good studies to show that men who get screened and treated for prostate cancer live longer than those who don't. So the benefits are unknown. But the harms of screening and treatment are real and well documented. They include not just the costs and pain of treatment, but also the incontinence and impotence that some men get after surgery. The problem is that some prostate cancer grows quickly and is lethal. Some, especially in older men, is slow-growing and never causes a problem. That is why people say that more older men die with prostate cancer than of prostate cancer.
Bottom line? Talk to your doctor about these recommendations and pick your screening tests wisely. Make sure that there is good evidence that the benefits outweigh the harms of both diagnosis and treatment.
Family physician Douglas Kamerow, a former assistant surgeon general, is a researcher at Research Triangle Institute. He lives in Maryland.