PSA Screening Conversation and Moving Forward With Prostate Cancer Research
PSA testing is a topic of conversation and controversy in the media because of the recent USPSTF (U.S. Preventive Services Task Force) recommendation against PSA screening.
The recommendation for PSA testing by the American Urological Association and its 18,000 urologist members and their harsh reaction to the USPSTF recommendation against testing seem to have been ignored in media coverage and by the USPSTF.
The official AUA statement (American Urological Association) said: (we are) “outraged at the USPSTF’s failure to amend its recommendations on prostate cancer testing to more adequately reflect the benefits of the prostate- specific antigen (PSA) test in the diagnosis of prostate cancer.”
(See full AUA statement on page 11 of this QUEST.)
PSA is really all there is for detecting prostate cancer early. The task force has made a huge error.
The main goal of early detection and screening programs is to allow a person to avoid a particularly unpleasant death, such as a death from prostate cancer.
Since the introduction of PSA screening in the United States, the prostate cancer death rate has decreased by more than 40%, and the percentage of men who have distant metastases and incurable disease at the time of diagnosis has decreased by 80%. In addition statistical teams at the National Institutes of Health concluded that up to 70% of these results are attributable directly to PSA testing.
The PSA test provides very powerful predictive information about a man’s risk for prostate cancer.
If we were to completely stop PSA testing in all men, it would result in countless men dying of metastatic prostate cancer.
Effects of Delayed Diagnosis
This USPSTF recommendation against PSA testing could result in delayed diagnosis of curable cancer in young men who many then become ill and ultimately die of prostate cancer.
Elimination of reimbursement for PSA testing, a possible consequence of this recommendation, would take us back to an era when prostate cancer was often discovered at advanced and incurable stages.
All this attention to PSA testing is not only misguided but, even more, takes energy away from efforts to find better diagnostic tools for the early detection, effective treatment, prevention and cure for prostate cancer.
Say what you will, prostate cancer is the second leading cause of cancer death in American men. Also, metastatic, advanced, prostate cancer causes prolonged pain and suffering.
Reduction in Deaths
Since the beginning of routine PSA testing, there has been an 80% reduction in the rate of advanced prostate cancer at diagnosis, and a 44% reduction in age-adjusted prostate cancer mortality in the United States. Similar patterns of reductions have emerged in other countries when PSA screening has been widely implemented and have not emerged where PSA screening is not widely used.
The figures clearly defend the idea that PSA testing helps save lives and diminishes suffering.
Some of the recent confusion and contro – versy is caused by a misinterpretation and a premature interpretation of results. Readers may refer to previous articles on our website: www.drcatalona.com
In addition, though, it is a problem over assigning death from prostate cancer versus death from other causes. When men have prostate cancer, are they dying from the prostate cancer or something else?
It is a fact that 1 of every 6 men will be diagnosed with prostate cancer and 1 of 30 will die of it. However, it takes far longer and is statistically far more demanding to prove an overall mortality benefit from prostate cancer screening. For example, because prostate cancer deaths account for a relatively small proportion of all deaths in the population, one could reduce the number of deaths from prostate cancer in the population by 50% through screening, and, since everyone eventually dies, it would take a very large screening study and very long follow-up to prove that it increased the average survival of the entire population of men screened.
In fact, screening programs for breast cancer and colorectal cancer have been accepted based specifically on the percentage reduction in breast cancer and colorectal cancer deaths, not fewer total deaths.
Furthermore, when you think about it, how would it be possible to reduce the number of men that die early of prostate cancer by 21-44% without increasing the overall survival of the men in the population. It is really misleading to use the absence (to date) of proof of an overall mortality benefit to claim that prostate cancer screening does not save lives.
As my colleague Dr. Patrick Walsh of John Hopkins, explained: “In 1990, before PSA testing, only 68% of newly diagnosed men had localized cancer and 21% were metastatic. Today, 91% are diagnosed with localized disease and only 4% have metastases.”
With the ability to diagnose cancer earlier and with treatment advances, US deaths from prostate cancer have fallen 44% in 18 years, a greater decline than for any other cancer.
Refinements in PSA Testing
So many refinements have been added to PSA interpretation such as percent free-PSA, PSA velocity, PSA density, and, in Europe and awaiting FDA approval in the US, pro-PSA-based phi test. These refinements were too new to be included as factors in past screening studies. Also, the PCA3 urine test has recently been approved by the FDA as an aid to early prostate cancer detection in men who have had a prior negative biopsy and still have a high or rising PSA level.
Walsh and I agree that until an alternative exists, prostate cancer testing is the best option we have to allow men to make an informed decision about treatment.
Because prostate cancer produces no symptoms until it is too far advanced to cure, as appropriate, men should have a PSA test and digital rectal examination.
Disparaging the test does a great disservice.
Hopefully, in the near future, we will have additional information in the area of genetics that will tell if prostate cancer is aggressive or not and which of several alternative treatments would work best for which patients. My researchers and I are focusing our collaborations in these areas.
Everything Involves Some Risk
It would be so nice if all information were perfect and no risk-taking were involved in medical decisions. But, unfortunately, that is not the case. We have to do the best we can with the information and knowledge we have and keep working to learn more.
In our continued search, though, we cannot deny men the opportunity for informed decision-making with the information we have. It needlessly places many patients with prostate cancer in positions of being denied a cure. To implement that denial based upon flawed and premature interpretations of studies would be unconscionable.
(American Urological Association)