Prostate Cancer Screening
The test you thought you needed but never knew you didn't.
Does not apply if you have a high risk because of family history, when screening may be of benefit to you.
Prostate cancer is very common. Prostate cancer is sometimes fatal.
Unnecessary treatment of trivial cancers is very common. Unnecessary treatment is sometimes fatal.
Do you see the pattern with this? When you have a very common disease- 80% of men have a prostate cancer by age 80- and an unreliable test, you may be as likely to do harm by testing as by taking your chances with the disease.
The PSA test is falsely positive 6 out of 10 times and falsely negative 2 out of 10 times.
This means that for every 100 men with a positive test result, 60 will have unnecessary further testing, treatment and even surgery. It also means that for every 100 cases of prostate cancer, the PSA blood test will falsely reassure 20 men. This is what is known as an inadequately specific or sensitive test. Put another way, it's just a plain bad terrible test that doesn't work!
The Amercians have calculated that for every 1000 men tested 30 to 40 men will develop erectile dysfunction or urinary incontinence due to treatment , 2 men will experience a serious cardiovascular event, such as a heart attack, due to treatment and 1 man will develop a serious blood clot in his leg or lungs due to treatment.
Worse, for every 3,000 men who are screened with the PSA test 1 man will die due to complications from surgical treatment.
PSA tests were designed as a way of tracking progress in people with known prostate cancer. It is useful in that context but not as a screening tool. It just doesn't work as a test for early prostate cancer.
So why don't we do something better? Well we might when we know what that is. So far, the best we can do is reduce unnecessary surgery and radiation in patients with false positives by doing MRI scans before we opt for biopsy.
Trouble is, with this many men and their uncertain prostate results we could spend an awful lot of money clearing up the mess. That's money we could really use in other parts of the health service. So PSA testing is also an opportunity cost that's just not worth it.
There is no Irish national screening programme for PSA testing. Even the usually keen to screen Americans have advised their doctors to stop doing this test. [ US Preventive Services Taskforce 2012]
This is not just because there is conflicting evidence from the research, but because the testing and investigation of false alarms does a lot of physical harm.
One of the two big studies looking at Prostate Cancer Screening with PSA tests showed a worthwhile mortality reduction. That was the European Randomised Study of Screening for Prostate Cancer. It showed a 20% reduction in deaths in men who had screening. The other big trial- the PLCO trial in the USA showed no benefit, but this may be because the men who were being compared to the men who had screening often had screening anyway. However, the biggest effect on mortality would appear to be coming from better treatments and not from screening itself. [Welch HG, Albertsen MPH. Reconsidering Prostate Cancer Mortality-The Future of PSA Screening. NEJM; Apr 16, 2020: 1557.]
There is now compelling evidence that screening for prostate cancer is not effective or not effective enough to justify the downsides. A review of all the major research has been published [Dragban I. et al Prostate cancer screening with PSA test: a systematic review and meta-analysis. BMJ 2018;362:k3519] and covers five studies of 750,000 men, and found that PSA screening is not helpful. Their conclusion is that no overall saving of lives is achieved despite a small improvement in the number of deaths from prostate cancer of 1 in 1000 men screened and at the cost of much anxiety, medical care costs and the following specific complications: 1 in 1000 hospitalised after biopsy with sepsis, 3 men in 1000 with long term incontinence and 25 with erectile dysfunction.
This review included the latest and highly relevant trial of screening by GPs in the UK [ Martin et al. Effect of a low intensity PSA based screening intervention on prostate cancer mortality. The CAP randomized clinical trial.JAMA.2018;319(9):883-895.] This study showed no benefit from screening.
Now some consultants still push PSA testing. I would argue that consultants who see the hard cases (younger men with aggressive prostate cancer) are not the right people to give advice on primary prevention. Their well meaning concern is inevitably coloured by the exposure to hard cases. Hard cases make bad laws. GPs or Public Health Specialists may have a more balanced view of whether screening is advisable for healthy populations.
What should you do? First of all, relax, most people with prostate cancer grow old and die with the disease and not because of it.
Secondly, talk to your GP or Urologist if you come from a family where people have died young of prostate cancer or had aggressive cancers.
Thirdly, do talk to your doctor if you have symptoms like urinary stinging, blood in the urine or pain in the area of your prostate gland.
Finally, don't buy any commercial kits for home testing. These will cost you quite a bit of money and a lot of sleepless nights: If doctors have a hard time figuring out what PSA results mean, you will be sure to be confused and alarmed if you try to do it for yourself.
So, enjoy this 'free' offer, the €0.00 PSA kit!