Screening to reduce lung cancer deaths
Lung Cancer We know that lung cancer is a big public health problem and whether screening adults for the disease will help is currently under much debate.
In the UK we are currently waiting for the results of a large European research study (NELSON) and a UK pilot of Lung Screening (UKLS). These studies will show if, with screening, you can reduce the number of people who die from lung cancer while minimising harm to those who are screen positivie but do not have the disease. The studies provide information on the kind of practical questions that are hugely important when considering such a large scale programme. Such as; how possible and even accessible screening for lung cancer can be, how many people will want or need to be screened, how easy it will be for medical staff to cope with pressures of extra patients and how many extra radiologists we may need, do we need new facilities and how many patients need follow-up, monitoring or treatment?
So you can see there are a number of questions that we need answers to before we can fully consider the possibility of implementing a lung screening programme in England. Until we are confident that we would do more good than harm for the population being offered screening at reasonable cost, we wouldn’t recommend such a programme. These kinds of considerations are the same when considering any population screening programme in the UK.
However, it is hugely important that people with any chest concerns see their doctor to discuss symptoms and anxieties and this wouldn’t change if we did implement a screening programme. What people often don’t realise is that screening is for healthy people who do not have any symptoms to identify their risk of developing a condition, so they can get help early. Screening isn’t for people with symptoms so speaking to your GP is always the best option if you have any concerns.
Interestingly, the US does not have a lung cancer screening programme as we mean it. When they see somebody with a heavy smoking history through their usual medical practices, they give them some extra tests. By contrast, what we mean by screening in the UK is that we go out and proactively find these people. By being proactive we invite people who would otherwise not have considered tests or treatment so the ethical imperative to do our absolute best for that person is very high. I don’t think that what we do is directly comparable to the US but of course there are still important lessons we can learn from their and other countries, experiences’.
In the UK we have an expert independent body, the UK National Screening Committee which reviews the evidence for and against systematic population screening programmes. This review looks at a wide variety of factors and we have 22 strict criteria to help us do this. To make sure any screening programme does more good than harm for the population being offered screening. The condition being screened for should be an important health problem, as judged by its frequency and severity, and do we know enough about it so we can ensure positive outcomes for people? Are there good, accurate tests? Is there effective treatment for the disease available? Do we have research evidence that shows that a population offered screening has less disease than a similar population treated in the usual way (by waiting for symptoms and seeing a doctor.)
If these criteria are not applied screening programmes can actually do more harm than good: in Japan, for example, they introduced a screening programme for neuroblastoma (a childhood cancer). Death rates from this condition were higher after the introduction of screening than they were before. This is because the natural history of the disease was not well understood and a number of children died from the treatment (which is quite severe in itself) when the disease may not have actually caused them any harm and might have gone away by itself.
Another example is why we do not screen men for prostate cancer in the UK. It is because the test is just not a good test, it leads to a number of men being given false results – these are called false positives and false negatives.