The Ever-Changing Landscape of Prostate Cancer Screening

uvmmedicine blogger Laura Donnelly '18
uvmmedicine blogger Laura Donnelly ’18

As a medical student attempting to get involved in research, it can be difficult to know where to start. My undergraduate work was in developmental biology, and while I learned molecular methods and laboratory techniques, I wanted to work on clinically-oriented research in medical school. I did not pursue research during the summer after my first year, but as second year continued, I began to look for a project. There are many opportunities at the University of Vermont for research, ranging from clinical and translational research, to basic sciences to population-based studies. I was fortunate to be offered an opportunity to work on a project assessing attitudes toward prostate cancer screening among primary care physicians in Vermont.

Prostate cancer screening is a controversial issue, due in large part to the disease course, the risks associated with diagnosis and intervention, and conflicting evidence regarding the value of prostate-specific antigen, or PSA-based, screening. Prostate cancer is the most commonly diagnosed cancer in males, aside from skin cancer. Symptoms manifest late in the course, and it is the second leading cause of cancer deaths among males. Because of this, there is significant interest in detecting it early, when intervention still has the potential to prevent metastatic disease and mortality. The advent of PSA-based screening in the 1990s increased prostate cancer detection rates.

However, there are concerns as to whether the increased rate of detection translates to decreased morbidity and mortality. Prostate cancer can be relatively indolent, with elderly males often dying with—not of—the disease. As a screening test, PSA testing is not diagnostic and, when indiscriminately used, non-specific. False positives may result in undue anguish for patients, as well as invasive diagnostic tests such as prostate biopsy, which carry associated risks. Given these consequences, the United States Preventive Services Task Force (USPSTF) determined that the potential benefits of screening did not outweigh the risks, and recommended against PSA-based screening in 2012. Unfortunately, the paucity of prostate cancer detection methods meant that no alternative was offered. ­Other professional organizations, such as the American Cancer Society and American Urological Association, have more nuanced guidelines which advocate for individualized decisions based on age and risk factors, as well as joint decision-making with patients.

The project I collaborated on found that the USPSTF statement had by far the greatest penetrance of any guidelines among primary care physicians in Vermont. Accordingly, far fewer physicians currently practicing use PSA-based screening when compared with those surveyed in 2001. Nevertheless, we found wide variation in screening practices in Vermont, particularly when the data was stratified by number of years in practice. This may be due to any number of factors, including the somewhat contradictory guidelines available, the changing nature of these guidelines, and physician and patient preferences. The USPSTF is currently re-evaluating their stance on prostate cancer screening, and this question will require continued investigation.

I am grateful to have been able to add to the knowledge base on this dynamic issue by looking at screening practices in Vermont. Not only do screening guidelines affect multiple specialties, including urology and primary care, it is a subject of great interest to public health, as it impacts a large portion of the population.

What are your thoughts about this topic?