The PSA test is a blood test to screen for prostate cancer. For years it has been recommended as part of routine preventive care for healthy men. The benefits of PSA testing has been a controversial subject for years but more recently has come under the radar because of the recent recommendation by the U.S. Preventive Task Force to stop prostate cancer screening in healthy men.
The following is an excerpt from a blog on the very popular Kevin Pho M.D. site. The analogy sheds light on the realities of PSA screening and really makes you question the risks and benefits of other cancer screening tests that have become a routine part of our health care.
Cancer screening is generally presented only in a positive light in mainstream media. “Early detection saves lives,” is what we often hear. But the reality is more nuanced, and unfortunately, isn’t prone to pat soundbites or inspirational ad campaigns.
Consider the following metaphor that illustrates this phenomenon, starkly told by David Newman, a director of clinical research at Mount Sinai School of Medicine in Manhattan:
“Imagine you are one of 100 men in a room,” [Newman] says. “Seventeen of you will be diagnosed with prostate cancer, and three are destined to die from it. But nobody knows which ones.” Now imagine there is a man wearing a white coat on the other side of the door. In his hand are 17 pills, one of which will save the life of one of the men with prostate cancer. “You’d probably want to invite him into the room to deliver the pill, wouldn’t you?” Newman says.
Statistics for the effects of P.S.A. testing are often represented this way — only in terms of possible benefit. But Newman says that to completely convey the P.S.A. screening story, you have to extend the metaphor. After handing out the pills, the man in the white coat randomly shoots one of the 17 men dead. Then he shoots 10 more in the groin, leaving them impotent or incontinent.
Newman pauses. “Now would you open that door?” He argues that the only way to measure any screening test or treatment accurately is to examine overall mortality. That means researchers must look not just at the number of deaths from the disease but also at the number of deaths caused by treatment.
The potential risks of cancer screening needs to be presented in the same light as its benefits. That includes the possibility of harm from increasingly invasive testing, along with complications from treatment.
Only when this complete picture is presented in the media can patients make a better informed decision.
The bottom line is that men need to be presented with unbiased information on the benefits as well as the risks of early detection and treatment. It may just be a “simple blood test” but the results of this test can open the door to invasive testing and treatment that cause more harm than good.