Prostate Cancer Screening

Prostate Cancer Screening is Valuable When Appropriately Applied
Pat Fox Fulgham, M.D., DABU, FACS
August 8, 2008

A recently released report from the U.S. Preventative Services Task Force in the Annals of Internal Medicine this month has once again called into question the value of prostate cancer screening. This study is an update to a previous study released in 2002. At that time, the task force concluded that there was insufficient information to recommend for or against prostate cancer screening in all men. The ultimate recommendation was that all men should be counseled about the potential risks and harms of the diagnosis and treatment of prostate cancer before they underwent a screening test. That recommendation remains intact. The new information in the current report from the task force is the recommendation that men over the age of 75 not be screened for prostate cancer since the risks and harms may outweigh the potential benefits of treatment.

Unfortunately, many men will generalize this recommendation to mean that PSA and prostate cancer screening are not valuable at any age. The task force freely admits in the full body of its paper that its recommendations are severely limited by the lack of well-designed, controlled studies regarding the risks and benefits of prostate cancer screening.

While the results of many of these screening studies are conflicting, there are at least two important pieces of data which must be explained.

1) The prostate cancer mortality rate in the United States has steadily fallen over the last 10 to 12 years since the introduction of PSA testing and popularization of annual screening with PSA and digital rectal examination. While there have been some improvements in treatment for prostate cancer which could account for better survival rates, by far, a more probable explanation is early diagnosis based on PSA screening. The age-adjusted mortality rate for prostate cancer in the United States is at its lowest level in 30 years and continues to decline.

2) Populations of men who are routinely screened have a lower mortality rate than populations of men who are not. A 2004 study study performed in Austria showed that in a county (Tyrol) where all residents ages 40 to 79 undergo routine annual screening for prostate cancer using PSA and digital rectal exam the mortality rate from prostate cancer is 30% lower than in adjacent counties where routine screening is not offered. While not conclusive these data are strongly suggestive that PSA screening has made a dramatic difference in the mortality rate from prostate cancer in this country.

Since very few men die within 10 years of the diagnosis of prostate cancer it is reasonable to suggest that routine screening in patients with a life expectancy less than 10 years is probably not warranted. However, it is also true that patients may experience significant decrement in the quality of their lifetime (even if its length is not cut short) when prostate cancer is undiagnosed and presents at an advanced stage. Therefore, even men who are older than 75 should be assessed for whether undiagnosed prostate cancer could cause substantial harm (such as pathologic fractures of the bones or obstruction of the urinary tract) in their residual lifetime.

It has long been known that PSA is an imperfect screening tool. Nevertheless, it may be used to identify patients at an increased risk for prostate cancer. A number of modifications of PSA screening have been used to improve the predictive capabilities of the test. It is my belief that early diagnosis will ultimately prove to be extremely valuable to the general population whether it is accomplished by PSA testing or some as yet undeveloped more sensitive marker.

We have only just begun to succeed in convincing men of the importance of preventative medicine and the positive impact of a healthy lifestyle and routine medical testing. We should not discourage men from taking advantage of an opportunity to recognize a potentially fatal disease in its early stages. I believe that patients are sophisticated enough, with the help of their physician, to evaluate the potential risks and benefits of treatment and then make an informed decision. We should not let the lack of certainty about the benefits of screening prevent us from building upon the exhilarating improvement in mortality rates over the last 15 years.