Choosing to be tested and screened for various diseases and health conditions is a tough decision. For many patients, testing does not improve health and can cause – rather than relieve – anxiety. That’s certainly the case for prostate cancer, which is the most commonly diagnosed non-skin cancer in men and the third leading cause of cancer-related death among men in Canada (1). The good news is the long-term prognosis is encouraging: the 10-year estimated survival ratio is 95%, the highest among all cancers in men (2). The bad news is that a widely-used screening tool for prostate cancer - the prostate-specific antigen (PSA) test - is not very reliable.
The PSA test is a blood test to check for the presence of a protein that is produced by the prostate cells. A high PSA level may be a red flag for cancer, although not necessarily. 'False positive' results are also common. A prostate cancer diagnosis can be scary and many men do die of the disease, but most cases of prostate cancer actually progress slowly and men can live with prostate cancer without symptoms. A positive result from a PSA test can cause a lot of anxiety for men, particularly when the results are false, or lead to the detection of cancers that never would have progressed to the point of causing death or any health concerns. Meanwhile, men who test high for PSA levels usually undergo further tests including prostate biopsy, which is painful and may cause infection, blood in the urine and hospitalization.
These issues have prompted researchers to look more closely at the pros and cons of PSA testing. A systematic review from 2014, conducted in partnership with the Canadian Task Force on Preventative Health Care, examined the results of three randomized controlled trials involving more than 200,000 men (3). More recently, a systematic review containing three randomized controlled trials involving more than 600,000 men was conducted for the US Preventive Services Task Force (4).The purpose of these reviews was to assess the benefits and harms of screening for prostate cancer using the PSA test (3;4).
What the research tells us
The benefits of PSA screening were not consistent between studies. What were notable were the associated harms of screening including high chance of false-positive results, the dangers of complications from follow-up prostate biopsies, and overdiagnosis (3;4). These potential risks, weighed against the benefits, led the Canadian Task Force on Preventative Health Care to recommend the PSA test not be used to screen for cancer, particularly in men under the age of 55 and over the age of 70 (3). Men aged 55 to 69, the highest risk group, are advised to seek expert advice and find out about other options before deciding to have a PSA test (3).
It is important to note that the task force’s recommendation is not a universally accepted one. For example Prostate Cancer Canada’s position is that the benefits of PSA screening outweigh the negatives and that eliminating it would result in a significant increase in prostate cancer deaths (5).
So what’s a guy to do?! As always, and particularly in this case, men are urged to consult with their doctors to fully understand the benefits and harms of PSA testing. Your physician will help you choose the best course of action based on your individual circumstances (including ethnicity, family history of disease and other risk factors) and personal preferences. Decision aids in the form of brief booklets are also available to help you make informed choices about tough issues such as prostate cancer screening (6).
One thing everyone agrees on: new, more accurate and effective screening tools are urgently needed to safely detect and treat prostate cancer.
Need help making a decision about prostate cancer screening? Click here for a decision aid on the topic.
