EDITOR'S NOTE: This blog was originally published on June 29. Due to recent questions on this topic, it's been reposted. News reports say the United States Preventive Services Task Force will next week release new recommendations saying that healthy men should no longer receive a PSA blood test to screen for prostate cancer. Reports say the USPSTF will say the test does not save lives and often leads to more tests and treatments that needlessly cause pain, impotence and incontinence. Otis W. Brawley, M.D., chief medical officer of the American Cancer Society, says the Society cannot comment on the evidence review or on the recommendations until they are made public.
By Otis W. Brawley, MD, FACP
Prostate cancer is a major public health problem. The American Cancer Society estimates that 240,890 American men will be diagnosed with prostate cancer in 2011 and 33.720 will die of it. It is the second leading cause of cancer death among men, only surpassed by lung cancer.
Prostate cancer screening became common in the U.S. in the early 1990s and dramatically changed the demographic of cancer in the U.S. Prostate cancer quickly became the most commonly diagnosed non-skin cancer. Today an American male has a lifetime risk of prostate cancer diagnosis of about 1 in 6 and a lifetime risk of dying of only 1 in 36. In Western European countries where screening is not common, the lifetime risk of prostate cancer diagnosis is much lower, about 1 in 10, and the lifetime risk of death is the same.
Screening began without the completion of the scientific research to show that it saves lives. For most advocates of screening and aggressive treatment, there was and is a desire to do something that might be beneficial to the population of men at risk. Unfortunately, the history of medicine is filled with examples of physicians "jumping the gun" and using possible interventions before they are fully evaluated.
The problem with prostate cancer screening is this cancer has a varied biologic behavior. Many, perhaps even most, men with diagnosed localized prostate cancer have a disease that will never progress and cause harm. Treatment for these men will only cause side effects. They are cured, but do not need to be cured.
On the other hand, some men with apparently localized disease have a cancer that will progress and ultimately kill. Treatment of these men may save them from a prostate cancer death.
The quandary in prostate cancer medicine is best summarized by Dr. Willet Whitmore, former Chief of Urology at Memorial Sloan Kettering Cancer Center: "When cure is possible, is it necessary? When cure is necessary, is it possible?"
Another very wise urologist, Dr. Paul Shellhammer, once used the words of Whitmore to further explain that we know there are two kinds of prostate cancer and we hope there is a third.
- 1. There is the kind that can be cured, but need not be cured.
- 2. There is the kind that needs to be cured and cannot be cured.
- 3. We all hope there is the kind that needs to be cured and can be cured.
Recommendations Acknowledge Uncertainty
"Do screening programs save lives?" is a legitimate question. In the past 2 years there have been several publications of interim analyses of large prostate cancer screening studies causing several organizations to re-evaluate their prostate cancer screening recommendations. It is of note that all major organizations that have a process for evaluating data and developing screening recommendations recognize that the utility of PSA screening is legitimately open to question. All statements leave open the possibility of a benefit to screening but they note that the harms of screening are better proven than the benefits.
- The American Urologic Association in its 2009 "PSA Screening Best Practice" statement recommends that prostate cancer screening be done but says, "Given the uncertainty that PSA testing results in more benefit than harm, a thoughtful and broad approach to PSA is critical. Patients need to be informed of the risks and benefits of testing before it is undertaken. The risks of overdetection and overtreatment should be included in this discussion. "
- The European Association of Urology has made a statement that recommends for informed decision making within the physician-patient relationship and against mass screening in which informed decision making is difficult. They state, "Men should obtain information on the risks and potential benefits of screening and make an individual decision."
- The National Comprehensive Cancer Network says, "There are advantages and disadvantages to having a PSA test, and there is no 'right' answer about PSA testing for everyone. Each man should make an informed decision about whether the PSA test is right for him."
- The American Cancer Society screening statements have been largely consistent with the above statements since 1997. The 2010 ACS statement says, "men should have an opportunity to make an informed decision with their health care provider about whether to be screened for prostate cancer, after receiving information about the uncertainties, risks, and potential benefits associated with prostate cancer screening."
The controversy concerning the usefulness of PSA screening is likely to continue for some time. Even many physicians do not understand that screening and aggressive therapy might be net harmful for the population of men at risk. It is best that men and their physicians be:
- Aware that there is a legitimate controversy about screening.
- Familiar with the recommendations of these organizations.
A man choosing regular screening might benefit in that his life might be saved. That man might also be harmed by suffering the effects of unnecessary diagnosis and treatment. I say "unnecessary diagnosis" as there are now studies showing that men concerned about a diagnosed prostate cancer have a higher risk of depression and suicide.
We all need to keep an open mind regarding screening and support the basic and clinical research which might ultimately allow us to predict the localized prostate cancers that are destined to progress versus those localized cancers that are destined to remain dormant. If we find and validate such a test we can actually determine just how good our current treatments are.
