Health Policy for Prostate Cancer: PSA Screening as Case Study

PSA testing: an ongoing dialogue

Prostate-specific antigen (PSA)-based screening for early detection of prostate cancer was approved in two stages by the US Food and Drug Administration (FDA). In 1986, the blood test was approved mainly to monitor disease status in men already diagnosed with prostate cancer. In 1992, it was approved for prostate cancer diagnosis. Following its approval, the test was subsequently used to detect disease in asymptomatic men (screening) as well as in men presenting with urological symptoms, in spite of not having been approved for these indication.

The statistics

Approximately one in six American males is diagnosed with invasive prostate cancer in his lifetime. Prostate cancer is the second leading cause of death from cancer, following lung cancer; a considerable public health burden. However, in spite of its high incidence, only one out of every 36 American men over the age of 50 dies of prostate cancer. In terms of mortality, it is true then, that more men die with, rather than of prostate cancer. It is also true, that in the past 15 years, the risk of prostate cancer and incidence of the disease has increased with a corresponding decrease in mortality from the disease. For instance, it has been proposed that, “Prostate cancer-specific mortality has declined … but several reasons for this trend have been suggested, such as improvements in medical treatment of advanced disease.”

What needs to be investigated is that the decrease in mortality from the disease is directly a cause of widespread PSA screening, or is a result of other factors such as aggressive surgery, radiation or hormonal therapy. United States Preventative Services Task Force (USPSTF) chair, Virginia A. Moyer, has previously stated that there is no evidence regarding this:

We actually don’t have a solid explanation for the decline in mortality. PSA advocates believe that we should be paying attention to the Göteborg study, which shows that if there is benefit, it begins to accrue at about 9 years. However, the decline in prostate cancer mortality began around 1993, at the same time the widespread use of PSA began. If the decline were a result of screening, you would expect to see the curve drop around 2003, but it occurred in 1993. While there may be some benefit in PSA tests, the numbers don’t bear out the theory supporting screening for the decline in mortality.