Cervical smears are used to screen for cancer of the cervix in women. Can PSA be used as a test to screen for cancer of the prostate in the same way? This is a difficult question to answer because there is no clear difference between the amount of PSA found in the blood of men with cancer and of men with simple BPH and other benign conditions.
In America it is now very popular for men to have their PSA checked once a year, and there is no doubt that this finds a lot of cancers that are not causing any symptoms. These men usually will have a radical prostatectomy, and so it is now becoming one of the most common operations in America.
It is natural for men in Britain to wonder why screening is not done here – they may have a cancer causing no symptoms that could be cured if it was diagnosed early. The issue is very complicated, however, and urologists and cancer specialists do not yet agree.
In the first place, for every person who has cancer diagnosed in this way, many others will have to have tests done, and will experience a lot of worry waiting for the results. If cancer is found, a radical prostatectomy (or perhaps radiotherapy) will be necessary to get rid of the cancer, and this is a fairly serious operation. All this would be worthwhile if it produced a large reduction in the number of men dying from cancer of the prostate. However, some very early cancers grow slowly and in many cases might never cause harm, so it is not too clear how many lives would be saved. This is especially the case with older men, so although it might be a good idea to check the PSA in a man aged over 55, it is less likely to be done in men aged over 75.
Most specialists think it is too early to recommend screening of men without prostate symptoms, but research into the value of screening is going on. If a more specific test were found for cancer, and if ways were discovered of deciding which early cancers are dangerous, it would be easier to recommend screening. It would also easier if there were a simpler treatment than radical prostatectomy.
As a general rule, it is probably wise to measure the PSA in a man who has prostatic symptoms, as such symptoms can be due to cancer of the prostate and, if they are, they may need different treatment from that required if they were due to BPH. Because of this, most British urologists are seeing more men with prostatic cancer. Ten years ago this operation was not often done in the UK and would have received only a brief mention. It is now part of the regular treatment in many urology departments, largely because of earlier diagnosis through using the PSA test.