(December 2011) by Dr Stephen Barker
Right now the press and media are awash with stories about prostate cancer and screening. These stories inevitably beg the question – ‘Why don’t we have a national screening programme for prostate cancer?’ It seems so simple – enroll all New Zealand men in a screening programme and away we go! However, as with most things medical, it is not that easy. I have no doubt that one day we will have some form of national prostate screening. But there are good reasons why it may take a while longer to sort out exactly how this will look.
Firstly, the PSA (Prostate Specific Antigen) test – undeniably one of the most useful we have available in modern medical practice – is not fool-proof. There are a significant number of false negative and false positive results when using the PSA. Other conditions aside from cancer may raise the level, creating artificial anxiety. So, whilst it is a great test, it’s not perfect.
Secondly, what happens when a PSA test is confirmed as genuinely elevated? Typically, the next step is a prostate biopsy. This is a potentially uncomfortable test where a biopsy needle is passed via the rectum, directly into the prostate tissue, sampling several areas of the prostate. The test itself carries a small risk of bleeding and infection. Again, there are a number of false negative and false positive results that may occur.
If prostate cancer is diagnosed following the biopsy, then there is the question of what to expect regarding the progress of the cancer, and whether to treat or not to treat. Prostate cancer does not behave in the same way for everybody. On average, the older one is, the more likely it is that the prostate cancer will give less overall trouble. Whereas, in younger patients, there is more chance of aggressive prostate cancer. The latest studies support early treatment of prostate cancer, especially in younger men (‘younger’ usually means 50s or so guys!). However, it’s well known that treatment itself may have unwanted side effects.
As with every field of medicine, there will no doubt be improvements in the diagnostic tools and the treatment options. For the present though, it remains important to create the right kind of screening programme – one that maximises diagnostic benefit to some, yet minimises harm to the rest of the screened population. Meantime, most GPs are happy to offer a PSA test to male patients on an individual basis following appropriate discussion.