Prostate Cancer Screening - Should we do it?
What is PSA?
PSA is a protein produced by normal as well as malignant or cancer cells of the prostate gland. The PSA test is a blood test which can identify men with an increased probability of having undiagnosed prostate cancer. A man’s PSA test can be abnormal when he does not have cancer and can be normal when he does have cancer so it is not a perfect test.
Hence, there is great debate about whether it should be offered routinely and at the moment, in Australia it is up to the man to ask for the test for it to be done.
What are the risks and benefits of doing a PSA test?
The benefits of doing a PSA include early detection of cancer and this is particularly important if a man is high risk for developing prostate cancer. Risk factors include family history, carrying a BRCA- gene (typically associated with breast cancer), increasing age, African-American race, smoking and obesity. Early diagnosis allows early treatment and improved survival rates.
Given that prostate cancer is the second most commonly diagnosed cancer in Australian men (after skin cancer), and the second most common cause of cancer death in Australian men (after lung cancer), early detection could have a big impact on Australian men.
A potential risk of PSA screening includes a false positive result. A false positive result might be caused by elevation of PSA secondary to infection of the prostate (prostatitis), a urinary tract infection or a multitude of other causes and this can lead to undue stress.
This is a problem, because it may result in an unnecessary prostate biopsy. Prostate biopsies are at times not only painful but can be associated with risks such as infection. However, prostate MRI’s are now available and funded by Medicare when ordered by a urologist and have significantly reduced the need for unnecessary biopsies.
Another risk is detection of a very early cancer which might not need any treatment but the knowledge that it is there might cause potential stress and anxiety. Men will then also need to make decisions regarding treatment which may have potential side effects. This is “over-diagnosis” as some of these cancers whilst “real cancers” may never have caused the man any problems throughout his life.
The treatment for prostate cancer has also become much more refined so that side effects like erectile dysfunction and incontinence are now much less common.
What are the current recommendations??
The guidelines below have been endorsed by the National Health and Medical Research Council, Urological Society of Australia and New Zealand and the Royal Australian College of General Practitioners.
For those who decide to have prostate cancer tests, the general recommendation is to have a PSA blood test every 2 years from age 50 to age 69.
For men whose risk of prostate cancer is higher than average, regular testing can start earlier.
PSA testing is not recommended for a man who is unlikely to live for another 7 years.
If the PSA > 3.0 ng/mL, investigate further. i.e. refer to a urologist or repeat PSA in another 1 – 3 months with a free to total PSA ratio
Do not offer PSA testing at age 40 years to predict risk of prostate cancer death
In men with no prostate cancer symptoms who want testing for early diagnosis of prostate cancer, DRE is not recommended as a routine addition to PSA testing in the GP setting
Measurement of PSA velocity is not recommended to increase specificity of a total PSA test result of 3.0 ng/mL or greater.
Summary
Prostate cancer is a significant cause of cancer related death and morbidity in Australian men. Now that we have Medicare funded MRI and sophisticated algorithms to calculate likelihood that a man’s prostate biopsy will be positive, we are seeing far less prostate biopsies being done and far more positive prostate biopsies. Prostate therapies have also been refined so that watchful waiting and monitoring of early cancers can be done and targeted therapies with less side effects are available. PSA is now being recognized as a good screening tool which should be offered to men when they turn 50 years as long as the risks and the benefits are clearly explained.
References
1. Cancer Council Australia: Clinical Guidelines Network (20/01/2016), Clinical practice guidelines for PSA testing and early management of test-detected prostate cancer, viewed 10/10/2020 <https://wiki.cancer.org.au/australia/Guidelines:PSA_Testing>
2. National Health and Medical Research Council (March 2014), PSA Testing for Prostate Cancer in Asymptomatic Men: Information for Health Practitioners, The Australian Government.
3. The Royal Australian College of General Practitioners (August 2015). Should I have Prostate Cancer Screening?, viewed 10/10/2020 <https://www.racgp.org.au/download/Documents/Guidelines/prostate-cancer-screening
