Prostate testing remains controversial. In one camp we have those who are pushing for more testing so that more cancers can be detected. This group feels that prostate cancer is under diagnosed and under treated. In the opposing camp are those who feel prostate testing is not helpful as a screening (as against a diagnostic) test and feel that too many men have unnecessary biopsies and surgery with all the associated risks and possible complications. Interestingly, in this latter group is the inventor of the test.
Whilst stories of men who had their life “saved” by having a PSA test make the headlines, stories of men who have incontinence and impotence after unnecessary surgery do not.
What is the average man to make of this? The issues are not straightforward.
The PSA test measures a protein in the blood, which comes from the prostate gland. Like with all tests there is a statistically defined normal range and this increases with age. There is also a sub set of “free” PSA versus PSA bound to another protein.
In an ideal world a raised PSA would diagnose prostate cancer. It does not. The level can be raised for a number of other reasons including benign enlargement, infection and can be raised by some over the counter medications. The PSA can also be normal even if cancer is present. In medical terms this test is classed as having a high” false” positive and negative rate.
It gets more complicated. There are two types of prostate cancer. One form which is fatal and the other is not. In simplest terms it has been regarded that all men will eventually get cancer cells in the prostate if they live long enough. They will die with not of the cancer. Hence the finding of prostate cancer in someone of 70 is regarded as less serious than in someone of 55. Age whilst a guide, is again not an absolute determinant of the form of cancer. The PSA does not give us any clue either.
The final complication is that in many instances we do not know if treatment makes a difference. In other words in many cases we do not know if a man who has undergone surgery and radiation and lives would have lived just as long without treatment.
There are conflicting trial results too. An Australian study claims that Australian men are under diagnosed and under treated. This is based on the fact that 60% of biopsies were positive for cancer compared to 30% in the USA. It also found that when radical prostatectomy was performed that on 5% had “insignificant “ cancer compared to 25% in the USA. This could also be interpreted, as showing that there is better case selection for surgery in Australia.
Once again it would be simple if the finding of cancer and treatment meant a better and longer life. A large American trial over ten years showed PSA screening did not reduce death rates in men over 55. A European study showed a small decrease in death rates. For every 48 operations there was an increased survival of one. This means 47 men had surgery, which can cause incontinence and impotence for no net gain.
The Australian study is being promoted by the Urological Society, which advocates PSA testing for all men over 40. It is worth remembering that their members earn a living from biopsies and surgery. This does not make their advice wrong but they have a vested interest. Other Australian groups recommend screening after 60 or no screening at all.
The tests inventor, Richard J Albin went public saying he never intended the test to be used as a screening tool and claims the original FDA approval was based on it detecting 3.8% of Prostate cancers. Whilst the case rate of Prostate cancer in the USA is 16% there is only a 3% death rate from it.
So to get back to our question of what are we to make of this? The simple answer is we do not know. Those who claim to have the answer need to be treated with great skepticism. Those who claim they are about “saving lives” need to be treated the same. Those who downplay the not insignificant costs in human terms of over treatment are not doing us any favors.
Ultimately the decision needs to come down to the individual based on his circumstances. Factors like family history and symptoms need to be considered. If a PSA is done and is raised it should certainly be repeated before further action is considered. Men need to be aware that it is not black and white; that a positive test may mean nothing and a negative test does not mean absolutely no cancer.
Whilst it would be nice to be able to offer a simple one size fits all advisory, I do not believe this is possible. Hence beware of those who do particularly if they stand to gain monetarily from it.