Interview 01

Age at interview: 62

Brief Outline: Sir Iain Chalmers practised as a medical doctor until 1973. Until recently he was a director of the UK Cochrane Centre. He is now editor of the James Lind Library www.jameslindlibrary.org.

Background: Occupation' Editor, James Lind Library. Marital status' married. Number of children' 2. Ethnic background' White British.

Explains what PSA stands for and why the test is done.

Well PSA stands for prostate specific antigen and it's a substance that can be measured in the blood and it comes from the prostate gland; and the purpose of people being interested in it is that they think it might help people to pick up prostate cancer early in such a way that the outcome of the disease, the prostate cancer, will be less likely to harm the patient.
 

Suggests that the PSA test may be misleading and lead to great anxiety.

Fine now I'd like to ask you about your views about the screening, in other words inviting healthy men to come to the doctors for a PSA test please?

Well I guess that I'm a bit of a snail when it comes to screening in that as most people know, a screening test can tell you the truth about some serious problem that's there but it can also mislead you in both directions. A positive test might arise when in fact there is no serious problem, and a negative test might miss a problem that's actually there. So in both of those directions there's the possibility for doing harm unintentionally and so I think people, particularly people who are feeling perfectly healthy, should be well informed about these limitations of screening tests before they go in for them.

What sort of side effects or possible treatments do you think men should be told about?

Well I'd be worried first of all about the side effects of a positive test, and the biggest side effect is probably anxiety. And it's, I think, probably not sufficiently taken into account that some people, and I'm one of them, can be quite anxious faced with the result of a test which isn't certain, and then go on to have other tests which are more invasive, if you like, than a simple blood test. So people need to know about that, but in particular they need to know well if it does turn out that this test identifies a cancer that's there, a real cancer that's there, what are the treatment options and what difference do they make to, for example my life expectancy, as one example, and what are the side effects of the treatments as well. And when not enough is known about those one can find oneself being treated for a disease and being labelled as being a cancer sufferer if you like, a good deal earlier than might otherwise have been the case and you want to be very clear that that's got advantages as compared with, for example, going to your doctor when you've got some troubling symptoms, and then the doctor examines you and does things in response to the fact that you've gone to the doctor rather than the doctor has offered a screening test in spite of the fact that you appear to be well. 

I mean there are some conditions, blood pressure, raised blood pressure is a good example, where you may not have any symptoms and because there are important and effective treatments for them it is a good idea for a doctor to check your blood pressure and see whether it's raised and if it is, may be to do some further investigations and to invite you to consider going on treatment. Because we know that treating high blood pressure can reduce your risk of stroke, which is a very serious condition. But the situation with PSA screening is not like that yet, may be it will become that, but the evidence that's so far available doesn't put it in that class of a screening test at all.
 

Argues that we don't know that earlier diagnosis and treatment of prostate cancer lengthens life but we do know that treatments have side effects.

So you think it's important that men are informed that treatment for prostate cancer doesn't necessarily lengthen life?

I think that in the current state of our knowledge it is important that they are told what the consequences are of earlier diagnosis as a result of PSA screening and what difference it makes, that we don't know what difference it makes to their life expectancy, but that we do know that some of the treatments have side effects, unwanted effects that some men would find very unacceptable. I mean incontinence is embarrassing quite apart from anything else, and quite frankly a bloody nuisance, so certainly one wouldn't want to go in for something which had that risk attached to it unless there was some pretty clear evidence of benefit on the other side; or anyway that's my position, I would want to think very carefully before going for a treatment of unproven effectiveness that sometimes causes incontinence.

And impotence you said?

And impotence, yes for some people that will be a more important problem than for others, but I could imagine that incontinence is likely to be a bind for almost any person who experiences it.
 

Explains that men are taking part in a large controlled trial to compare three different options; surgery, radiotherapy and active monitoring.

Would you like to go back to prostate cancer, what is the evidence at the moment about treatments?

Well one of the reasons that there is uncertainty is that prostate cancer is quite common, far more common than people realise, but it doesn't [always] kill people. In other words, you can die with prostate cancer but not of prostate cancer. So it's quite important, given that fact, that one is very clear about the quality of the evidence upon which you intervene early with some of the quite radical things which people are intervening with. For example radical prostatectomy, quite a major operation, to remove a prostate with some cancer in it, has side effects. It can cause incontinence, men can become impotent as a consequence of it and then of course it has the risks associated with any large operation, those associated with the anaesthesia or bleeding and so on. 

And then there is treatment given with radiotherapy as an alternative to that. There again there are problems which can be associated with the radiotherapy, so some people say, even when they know there is cancer there, well actually let's just watch the situation and if it does seem to be deteriorating fast only then intervene with one of these more radical treatments. And that uncertainty is currently reflected in the fact that men are participating in this country in a very big controlled trial comparing those three different options, the radical surgery, the radical radiotherapy and active monitoring of the situation. And as a result of that study and other similar studies, although I think the British one is probably the biggest and the best, people like me are going to be in a far better position to take an informed decision if we find ourselves in the circumstances where we do have an early prostate cancer diagnosed. And indeed, if I went to my doctor with symptoms and it did lead to a diagnosis, I think I would want to be invited to participate in that controlled trial. It's a way of hedging my bets because we don't know which is best, but also helping to produce the information that will make decision making in future by people in my position more informed than it would otherwise have been.