Research shows that although PSA tests can lead to non-essential treatment they still save thousands of lives each year
PSA (prostate specific antigen) tests have been used to screen men for prostate cancer for many years but lately the procedure has been criticised. Some studies indicated that raised PSA levels were not a good indicator of aggressive types of prostate cancer and in the US, where routine PSA blood tests for men over 50 were the norm, researchers have suggested that the practice could lead to unnecessary treatment. Recently, the US Preventative Services Task Force even went so far as to advise against offering PSA screening. The reason? PSA screening, it’s argued, might lead doctors to treat men who did not need it but would then have to suffer some of the unpleasant side effects (incontinence, erectile dysfunction). Here in the UK, men are not offered PSA tests as a routine but only if they request it or have symptoms.
However, in light of these criticisms, some have begun to question the value of PSA testing altogether. A new analysis of data from researchers at the University of Rochester Medical Center in New York has looked at what would happen if doctors were to stop PSA testing. They looked at data from a time when PSA testing was done less routinely than today, and compared it to current data when testing is standard. The results make for grim reading. Doing away with the test completely would likely result in a three-fold increase in the development of advanced-stage prostate cancer, meaning that the cancer would have spread to other parts of the body before diagnosis. Once the cancer has spread to other parts of the body is it obviously far more difficult – sometimes impossible – to treat. The researchers concluded that PSA testing and therefore, early detection, helps approximately 17,000 men in the US alone avoid advanced cancer every year.
These results, however grim-sounding, need to be put into context. PSA testing, when applied to men who do not have aggressive tumours, can lead to non-essential treatment and with it, unpleasant side effects. However, PSA testing when applied to men who have a more aggressive form of the disease can be life-saving because in these cases, if the tumour is removed before it has a chance to spread, the man will most likely survive; if the cancer spreads, his risk of death or at least of more invasive treatment, is raised dramatically.
But the main problem is that high PSA levels do not necessarily indicate cancer, and even when they do, it may not be an aggressive cancer. As with any medical test results, PSA levels need to be taken in context. High levels on their own do not indicate cancer, but taken with the results of a digital rectal exam, and any other signs or symptoms a man may have, they do point to a risk of cancer. Relying on one PSA test, however, could lead to men getting unnecessary treatment as levels may fluctuate. A recent urinary tract infection or an enlarged prostate can cause levels to rise, as can ejaculating before a test. So always ask to have your PSA levels checked twice.