The problem with skipping PSA screening tests

Earlier this week, the United States Preventative Services Task Force (USPSTF) published their final recommendation for prostate cancer screening. In October, the USPSTF released a draft of the new guidelines causing much debate and outrage from physicians and patients alike. However, despite public criticism, the task force left their guidelines unaltered, recommending against routine prostate specific antigen (PSA) screening in healthy men, regardless of age.

The problem with skipping PSA screening tests

The USPSTF is a panel of primary care physicians charged with the task of compiling evidence-based preventative medicine guidelines, but they lacks the presence of any urologist or oncologist. Proponents argue that this prevents the panel from being swayed by ideological or financial conflicts of interest. At the same time, the members of the panel are not experts in the field of prostate cancer and might not be as equipped to appreciate the benefits and harms of treatment as those who routinely treat the disease.  

The panel based its recommendations largely on two population based studies. One of them, the U.S. Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial, included over 76,000 men, and failed to find any mortality benefit in those screened, as compared to the control group after eight years. However, the majority of the control group was screened with PSA during the study and thus, the study was truly a comparison of annual screening versus intermittent screening.

The second study was the European Randomized Study of Screening for Prostate Cancer (ERSPC). This study included over 200,000 men who had either PSA screening every 4 years or no screening.  After following these men for 11 years, a 21 percent reduction in prostate cancer deaths was seen between the two groups.

Both of these studies are limited by their follow-up length of about 10 years, with the majority of experts feeling is an inadequate period of time, as prostate cancer can be slow to progress. However one randomized study that followed patients for an average of 14 years, detected a 44 percent reduction in prostate cancer deaths attributable to PSA screening.

Following trends in prostate cancer deaths in the U.S., however, is the most powerful argument in favor of PSA screening. Since the introduction of this test over 20 years ago, we have witnessed a greater than 40 percent reduction in prostate cancer mortality. On average, prostate cancer deaths have declined by 4.1 percent every year, with the number of deaths continuing to drop annually.

A new study published in the journal Cancer, investigated this trend to better establish the underlying cause of the steep decline in deaths.  The authors acknowledged that improvements in treatment may have had a significant role in decreasing mortality rates and created models to account for these variables. Ultimately, while treatment explains some of these improvements, the majority of the decline was unaccounted for, highlighting the impact of PSA screening in the decline of prostate cancer deaths.

Ultimately, at the center of the controversy, is the belief that PSA screening has led to the unnecessary treatment of many men, exposing patients to unnecessary harm. In reality, few question whether PSA screening is effective at preventing cancer deaths; the true question is whether the human cost is too great.

Prostate cancer can have an indolent course, not destined to cause death. However, 90 percent of patients receiving a diagnosis of prostate cancer elect active therapy, which increases their risk for complications, such as erectile dysfunction or incontinence.

Prostate cancer has the potential to be a devastating illness, killing approximately 28,000 men this year alone. At the same time, this should not scare patients into immediate treatment.  

As an urologist and oncologist, this is where I believe the true art of medicine is found.  PSA is only one part of the equation. A patient’s medical and family histories are very important, as well as prostate size and the trajectory of PSA results.

Furthermore, patients and clinicians need to be educated that not every high PSA requires a biopsy, and subsequently not all prostate cancers require treatment. This is reflected in the recommendations released by both the American Urological Association and American Cancer Association, which focuses on informed decision making, with patients choosing whether or not they want the test.

Currently, PSA is the only available tool for early diagnosis of prostate cancer and prior to it’s availability, prostate cancer tended to be diagnosed at more advanced, less treatable stages. While many disagree with the USPSTF’s recommendation, it does highlight a need for change in how an elevated PSA or prostate cancer diagnosis is handled.