The day I tried revolutionary new health MOT that can spot most cancers years before symptoms emerge

This summer, I will make a promise - “to have and to hold my wedded husband … for better for worse, for richer for poorer, in sickness and in health, to love and to cherish - till death us do part”.

Death. The part we try to gloss over.

But occasionally, mortality casts a shadow - especially for soon-to-be newlyweds who aren’t quite as young as they used to be.

As health editor of The Telegraph, I get to hear about all sorts of medical advances.

But few hold out as much hope as a new class of medicine, “liquid biopsies”, that could detect up to 70 types of cancer years before symptoms emerge - when the disease is most amenable to treatment.

Which is why I’m in a consulting room in central London, with my husband-to-be, having what may be the ultimate pre-marriage MOT.

I’m not the only one investing hope in such breakthroughs.

Currently, the NHS is embarked on the world’s largest trial of one type of liquid biopsy.

If the programme proves successful, screening - a simple regular blood test to predict the chance of cancer - could one day become the norm.

Such checks are already given by some health insurers in the United States.

But in this country, it’s a relatively limited enterprise.

The Cancer Screening Trust (CST), a not-for-profit company, is hoping to change that.

This year, it began offering a different type of liquid biopsy to private customers.

So far, trials suggest that it could spot more than nine in 10 cases of cancer at an early stage - an extraordinary achievement.

The million-dollar question is: how early?

Research on 30,000 people found the checks could identify 91.8 per cent of non-metastatic cases.This meant it was more treatable, because it had not spread beyond the primary site where it was found. The results were almost the same as those when disease was advanced.

The great hope is that the tests can prove equally effective at the first stages of cancer.

Here, the evidence is promising but far more limited. One study of breast cancer found the new technology was able to identify almost nine in 10 cases at stage one.

Currently, CST offers the checks, developed by Indian company Datar Cancer Genetics, at a price of £1,250, including a consultation.  

It wants to do far more.

For one thing, it wants a share of the NHS market.

Currently, the health service is embarked on what may be the biggest experiment in its history.

More than 140,000 people are taking part in the trial of another “liquid biopsy” test - Galleri, developed by the company GRAIL. First results are expected in early 2024.

So far, studies have found that the test - which can detect at least 50 types of cancer - is able to detect more than half of cases of disease.

Researchers hope it could prevent one in 10 cancer deaths.

Those offering the Trucheck test believe results so far suggest it may be still superior, particularly in finding cancer early, when it is extremely treatable.

Which takes us back to a consulting room in central London, where my partner Andrew and I provide a couple of vials of blood and wait 10 days for a telephone consultation.

CST only began offering the tests in August. Dr Richard Tippett, clinical lead, says that so far they have not had a “positive” result.

While everyone comes in search of an “all clear”, the consultant radiologist is aware that handling a “positive” cancer result from this service carries particular difficulties.

“What you get is a binary answer - essentially this is a test that says yes or no,” he said.

“While ‘no’ is straightforward, if you get a positive result it isn’t quite as simple as that. What we are saying is we found something, and now we need to find out exactly what it means.”

In some ways, that information is just the start of a journey.

The laboratories cannot tell the difference between a tiny renal growth, which might never cause any bother, and a fast-growing tumour that has death in its sights.

A positive result of these tests creates alarm for a patient - and in some cases, a dilemma, for the medics responsible for them.

Those with private health insurance will likely have the advantage, as they can quickly be referred on for further tests - such as MRI scans - to locate areas of concern.

But Dr Tippett says he is keen to ensure that the service works closely with the NHS, offering GPs as much information as possible to ensure that those who receive a positive result quickly undergo further checks.

“The great attribute of our test is that it will tell the GP exactly what organ is of concern, which will streamline referral pathways and subsequent investigations,” he said.

For some of us, the fear of cancer is a shadow from the past.

I’ve been largely lucky. Although diagnosed with a brain tumour aged 20, removal and subsequent treatment was successful. In the intervening decades regular checks have had their moments, resulting in a biopsy or two - but ultimately so far, so good.

Looking at my family background - Irish - the majority of deaths relate to heart disease and stroke - with the exception of my paternal grandmother, who died at 40 of pancreatic cancer.

For my partner Andrew, family history is a greater concern.

His father died of lung cancer, which was only detected at the latest of stages. Lung cancer outcomes in the UK are consistently poor, partly because so many cases are picked up so late. More than half of those diagnosed with stage one lung cancer will survive their cancer for five years or more after diagnosis.

But less than five in 100 people diagnosed with stage four disease are still alive five years later, making early diagnosis crucial.

So, for different reasons, we both undergo the tests, first going through a detailed questionnaire and consultation.

The blood test itself takes less than a minute, involving just two 10ml vials.

The system of liquid biopsies works by detecting circulating tumour cells that are released by malignant growths, but not from non-cancerous tissue.

Over a five-day process in the lab, healthy cells are stimulated to die.  

Cancer cells are resistant, meaning those that remain will grow and form clusters.

If these are identified, patients undergo an in-depth consultation, after which they can be booked in for further checks and continue private treatment, or take the information back to their GP.

Ten days later, we both breathe a sigh of relief when we get the all-clear.

We also receive the standard recommendation from CST - to repeat such checks annually.

If the NHS invests heavily in liquid biopsies and uses them as the basis for a national system of screening, it could transform the future of cancer diagnosis and treatment.

In the long-term, such a system could pay for itself. Finding cancer at such early stages means the treatment is far less costly and far more effective.

In the short-term, however, the costs are huge.

Many oncologists hope that one day, the simple blood tests could bring an end to the current system of screening - meaning no need for mammograms, or prostate and bowel cancer checks. But many experts say that day will only be reached when there is crystal clear evidence that the blood tests are able to spot disease early enough.

Independent experts call for further studies to see exactly how good the tests are at finding early-stage cancers, in real world populations.

Dr David Crosby, head of prevention and early detection research at Cancer Research UK, said results so far are promising - but said far more research is needed.

“Multi-cancer detection tests like these have huge potential, but we don’t yet know if they’ll have an impact on survival or quality of life for people with cancer, or where in the cancer journey they’re most useful,” he said.

At CST, Dr Tippett is also aware that some GPs may not be thrilled by the prospect of this new era of medicine.

In 2019, the Royal College of GPs issued a position statement saying that GPs should not have to deal with the results of any screening services that fall outside of those authorised for the NHS.

Family doctors - already struggling to cope with rising referrals for suspected cancer - are well aware that a deluge of patients clutching test results from a private company, with little idea what it means, will give them a major headache.

But with cancer, ignorance is hardly bliss.

Even before the pandemic set back progress, Britain has one of the worst records for early diagnosis of cancer in the Western world.

Since then, waiting times have deteriorated - with a doubling in the number left waiting for more than two months for treatment after an urgent referral for suspected cancer, and estimates that 22,000 people have missed treatment they should have had. 

While CST offers annual checks privately, it is also working with the NHS in the West Country about how the techniques could be usefully deployed at scale.

“We will want to look at particular cohorts - it could be that those at high risk for lung cancer are offered blood tests, rather than at the moment where it's more about CT scans. Or it could mean focusing on those with particular family histories,” said Dr Tippett.

“We are working with Exeter University to assess the impact of our tests on existing programs such as breast and colorectal cancer screening, as well as novel programs such as the newly launched lung cancer and non-specific symptom pathways.”

In the debate about the role of routine testing, critics suggest that one of the most fundamental risks is that they induce needless anxiety - with a risk of overdiagnosis and treatment of “precancers” that might never have caused harm.

Sometimes, such conversations are at risk of forgetting the anxiety which such patients are already carrying every day, said Dr Tippett.

“Some people are very nervous about the extra diagnostic burden this could place on the NHS,” he said..

“But at the moment, individuals are walking around with the burden - the burden of knowing someone in their family died from a disease that might affect them. To be able to get some answers - and to get them early - can be a great relief.”