Benefits and Harms of PSA Screening
Screening is a process of identifying apparently healthy people who may be at increased risk of a disease. The purported advantage of screening is to detect a disease at an early stage so that an individual can be offered information, additional tests and appropriate treatment to reduce their risk of complications or premature death.
The FDA approved the use of PSA for early detection of prostate cancer in 1994. Since its introduction, PSA testing has dramatically changed the landscape of prostate cancer, creating a significant rise in cancer incidence and shifting the stage of disease at the time of diagnosis to a much earlier and potentially more curable stage. The 20 year risk of death from prostate cancer for a 55 year old man is 1.0% with screening and 1.3% without. Although prostate cancer mortality has declined approximately 30% during this time, many experts argue that this decline is more attributable to improvements in treatment than screening.
Most recently, evidence has accumulated that any benefit of PSA screening is accompanied by a significant rate of overdetection and overtreatment of prostate cancer. Overdetection increases with age, rising from about 27% in men age 55 to about 56% at age 75. Most prostate cancers detected by screening with PSA are slow growing, not life threatening, and do not cause a man any harm during his lifetime. Unfortunately, there is currently no way to determine which cancers are likely to threaten a man’s health and which will not. Consequently, more than 90% of men with PSA-detected prostate cancer decide to undergo treatment. New evidence from a randomized trial of treatment of prostate cancer detected by PSA screening indicated that approximately one third of men who underwent prostate biopsy experienced pain, fever, bleeding, infection, or transient urinary tract difficulties. Serious harms can also result from treatment. For every 1,000 men treated, 30 to 40 develop erectile dysfunction or urinary incontinence due to treatment, 2 have a serious cardiovascular event, and 1 dies of complications from surgical treatment (European Cancer Conference 2013, Abstract 1481).
With this knowledge, several medical specialties have released updated guidelines in the past year. The United States Preventive Services Task Force (USPSTF) recommends that there is insufficient evidence to recommend PSA screening for anyone.
The American College of Physicians (ACP) recommends that physicians inform men between the ages of 50 and 69 years about the limited potential benefits and substantial harms of screening for prostate cancer. ACP further recommends that physicians should NOT screen for prostate cancer using the PSA test in average-risk men under the age of 50 years, men over the age of 69 years, or men with a life expectancy of less than 10 to 15 years.
The American Urological Association (AUA) guideline recommends that men between the ages of 55 to 69 years undergo shared decision making with their physician concerning the risks and benefits of PSA screening before undergoing PSA screening. AUA recommends against prostate cancer screening for men under age 40 years, men between the ages of 40 and 54 years at average risk and Men over the age 70 years or any man with less than a 10 to 15 year life expectancy.
PSA should be used as an additional tool in the diagnosis and management of prostate cancer instead of a screening tool. It should no longer be used to screen for prostate cancer in asymptomatic men with average risk for prostate cancer.
