The House Article | Too much information

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It’s a statistic that haunts me: one in 40. That’s the chance that my daughter will, like me, develop multiple sclerosis. For my son, the risk is lower, but these figures are the wrong side of negligible.

I might find them easier to push away if researchers were not making such rapid progress in being able to diagnose serious diseases early – sometimes up to a decade before the first symptoms appear. Would my children want to be tested, when they are old enough to decide? How would they cope with the prospect of a disease whose effects they have seen first hand?

These are questions that many more people will soon have to answer. AI-assisted research increasingly gives us the ability to identify the first, invisible signs of a disease. Scientists at the UK Biobank have access to half a million blood samples with which they can build metabolic profiles. Analysing data about the donors shows them which markers make a person likely to develop conditions such as dementia, cancer, diabetes and heart disease. Last year, a group of European researchers identified a test that traced how the body’s immune reaction to Epstein-Barr – a virus that infects nine in 10 of us – predicts whether it will lead to MS.

These breakthroughs are usually hailed as positive. In the case of a condition like diabetes, or certain cancers, they can prompt someone to improve their diet and activity to lower their risk. But diseases like dementia cannot be prevented with the drugs and interventions that are currently available. Where does that leave the future patient? Thanks to the internet, they can find out everything about what awaits them. Every memory lapse induces panic. Every twinge in the wrong place makes them fear that the end is beginning. It would take a sanguine personality to deal with an advance diagnosis of Alzheimer’s. According to polling for Alzheimer’s Research UK, half of Britons say it is the disease they fear most.

It is important to point out that widespread advance testing on the NHS is some way off, and the service cannot always deal promptly with patients who already have symptoms. “A third of people with dementia right now don’t actually have a diagnosis,” says David Thomas, head of policy at Alzheimer’s Research. “It is quite a big postcode lottery in terms of how long people have to wait.”

But private scans are readily available to those who can afford them. “Anyone can go for a private MRI scan of your brain, and you can get it yourself in the same way people at risk of Alzheimer’s can get a scan independent of the healthcare profession,” says Professor Gavin Giovannoni, chair of neurology at the Blizard Institute at Bart’s. “I don’t support that. I think unfiltered information that’s given in the wrong context is not helpful.” Thomas agrees: “We certainly wouldn’t be supportive of a healthy person receiving the blood tests at the moment. That’s a big challenge.”

The NHS already offers bowel and breast cancer testing to all over-50s. But last November, the National Screening Committee recommended against offering a blood test for prostate cancer. They found that although two lives would be saved out of every 1,000 men tested, up to 20 men would be overdiagnosed and undergo surgery, radiotherapy or treatment they did not need.

The difficulty is that not everyone with a biomarker will go on to develop a disease, or it may progress so slowly that they end up dying of something else. “We can see [the biological changes] 10 to 20 years before symptoms develop, but just because you’ve got those changes doesn’t mean you will go to develop Alzheimer’s disease,” says Thomas.

And treatments for Alzheimer’s are not good enough to justify giving them to people before they develop symptoms. “There are two treatments approved by the regulator, but not funded by the NHS, that have been shown to slow the progress. The benefit’s very modest.”

For MS, where treatments have advanced a great deal in the past two decades, there might be real advantages to preventative treatment. But the evidence is not yet available. Two tablets have been trialled on asymptomatic patients, but they have tough side effects and women must not get pregnant while taking them.

Still, even without treatment, says Kieran Winterburn, head of national influencing at the Alzheimer’s Society, there are advantages to early diagnosis. “For many people, not knowing is much worse than knowing. When diagnosis is done right, it actually reduces anxiety. It needs to be accompanied by a personal care plan, with people given the ability to monitor their health regularly and ensuring their carers and loved ones are able to access support.” They have the chance to put their financial affairs in order and talk to their families about what they want – although for some, these conversations will be extremely difficult.

Those who are willing to be tested will probably play a part in trials that save lives later on. We are at a “tipping point”, says Winterburn. “New treatments are coming down the line. Getting this right, seizing this opportunity we have right now, will hopefully lead us to a cure for dementia.”

Right now, I can see few advantages in encouraging my children to find out whether they are likely to develop MS. Catching the disease early would save money in the longer term because it postpones disability. “But unfortunately, NHS managers don’t think long-term,” says Giovannioni. “They work on an annual cycle.” So, the decision to implement a prevention programme is a political one. Health secretaries will base that decision on the data they have: the NHS might run a screening programme in half the country, treat cases with a worse prognosis and compare the outcomes with the other half. As patients would be part of a trial, they would not know whether they were at higher risk, and some would be given a placebo.

Thomas and Winterburn both talk about the “stigma” of an Alzheimer’s diagnosis. They hope that is changing. But as the controversy over assisted dying shows, western societies have only just begun to adapt to a world in which people will know much more about how and when they will die. In a culture where self-improvement and “wellness” is so important, dealing with that reality will be very hard.