Five new medical tests that will transform the future of health
If you follow the health headlines, there is often excitement about potential diagnostic or surveillance tests which may detect diseases earlier and help us live longer. Some of these tests are showing really promising results and form the basis of the academic research I’m working on as part of my PhD in bladder cancer.
I tend to get asked about these tests by patients I see in the clinic. However, while some of the data you may hear about shows promise, often these tests are still in the early stages of trialling. Some are not yet available to the public on the NHS or privately yet, while others may be closer to being commercially available.
So what stage are the following tests at, and how soon will you be able to access them?
1.DIY home smear tests
Currently offered to 25-64 year olds in the UK to reduce cervical cancer, cervical screening is an initiative that should make cervical cancer almost entirely preventable.
It prevents 70 per cent of cervical cancer deaths in England each year, but hat could increase to 83 per cent if more people attended.
In recent years the process of the cervical screening test (smear test) changed. The original from the previous ‘pap smear test’ to testing for human papilloma virus (HPV) in the first instance, which is the most common cause of cervical cancer. If HPV is detected, the sample is then tested for abnormal, (usually pre-cancerous) cells. If HPV is not found, then the risk for cervical cancer is extremely low and the cells do need to be tested.
Despite its effectiveness, uptake to the screening programme is declining, with many patients not attending. In an attempt to tackle the problem, a trial of DIY home smear tests was rolled out across London by researchers at King’s College London.
The YouScreen trial involved providing more than 27,000 women across north and east London who were overdue a smear test with the DIY kits either through the post or from their GP, when they had attended about a separate issue.
They then did a ‘self swab’ at home to check for the HPV virus. More than half of the patients included were over two years late for their smear test appointment. It’s predicted this initiative could increase screening coverage to 77.3 per cent if rolled out in England. It’s likely to be implemented as part of the NHS initiative to eliminate cervical cancer by 2040.
2. Blood test for cancer recurrence
A cancer is a growing tumour of abnormal cells and, just like our body cells, they contain their own unique DNA. Cancers release fragments of their own DNA, which can be detected in a patient’s blood via a simple blood test. These fragments are called circulating tumour DNA (ctDNA). Blood tests designed to pick up these fragments of cancer proteins (called ctDNA tests, sometimes also referred to as ‘liquid biopsy’) may predict cancer relapse earlier than it would show up on a traditional imaging scan such as a CT or PET scan.
For patients undergoing surgery for their cancer, which is often done with curative intent, this test could become a crucial step in monitoring for cancer recurrence, with serial blood tests drawn at time intervals aimed to pick the cancer up at an earlier stage, if it were to relapse. The test has been clinically validated in various different cancers with promising results in breast cancer, non-small cell lung cancer, colorectal cancer and bladder cancer. The cancer research I’m conducting at the moment is actually using these tests in the bladder cancer setting.
The impact of these tests is potentially transformative. Not only do they have the potential to predict cancer relapse earlier and improve outcomes for patients, but also, with further research, they could help monitor response to treatments and determine optimum duration of therapy, reducing both cost and, potentially, side-effects.
They could also help risk stratify patients (ie, assign them a risk status); we sometimes give chemotherapy or other treatments after surgery to prevent cancer recurrence. This is called adjuvant therapy. Using these tests may help to determine which patients need extra therapies after a surgery to reduce the risk of their cancer coming back and avoid potentially overtreating patients who don’t need this kind of adjuvant therapy – this is currently being tested in clinical trials.
We know that a lot of anxiety is felt by patients waiting weeks for scan results, and a simple blood test to monitor their cancer may be preferred.
For some cancers these tests are now available privately, but are very expensive and not yet available on the NHS until further research is available to support their use.
3. The new Alzheimer’s test
Another test with potential benefit is the novel blood test to detect Alzheimer’s disease years before clinical symptoms show. Alzheimer’s disease is a progressive neurodegenerative condition in which abnormal proteins build up in the brain, causing damage to the cerebral tissue and a resulting progressive decline in a patient’s cognitive function and memory.
The ALZpath blood test aims to identify ‘p-tau217’, a form of the tau protein, which is a hallmark protein in the development of Alzheimer’s disease and it seems to be as effective at picking up the disease in early trials as current diagnostic techniques.
Alzheimer’s is currently diagnosed via a combination of clinical signs, MRI imaging of the brain and lumbar punctures whereby a sample of cerebrospinal fluid is taken and tested for the hallmark proteins. Lumbar punctures require a specialised practitioner, are uncomfortable for patients and entail more risks compared to a blood test, which also costs half as much.
There is also more potential availability of this test on a global scale. Some early results of this new blood test, conducted on 786 participants, showed high diagnostic accuracy at detecting common proteins seen in Alzheimer’s disease. Diagnosing the disease earlier is important as there are some treatments available in the earlier stages (mild to moderate Alzheimer’s) to slow the progression, and early diagnosis can give patients more autonomy, involvement and decision making in the trajectory of their care.
While these results show promise, the test is still in the process of undergoing clinical validation. If successful, it would have to go through further regulatory approval and economic analyses before becoming publicly available, but the researchers remain optimistic and predict they could have a conclusion on this test within the next year.
4. Prostate cancer saliva test
Some early results presented at a recent oncology congress show the potential promise of a new test using patients’ saliva to detect men at increased risk of prostate cancer. The test aims to identify genetic factors that increase a man’s risk of developing prostate cancer, a disease which affects 55,000 men a year in the UK and results in around 12,000 deaths. Identifying which men are at increased risk of the disease could be pivotal in detecting the cancer earlier and improving outcomes for patients.
This is particularly important as we don’t have a national screening programme for prostate cancer, as whilst the PSA (prostate specific antigen) blood test is useful for monitoring, it’s not considered sensitive enough to be used in screening.
A saliva test would also be great from a patient’s perspective as it’s non-invasive and can be done from home. Patients would just spit into a pot and send it off in the post for testing. DNA would then be analysed from the saliva to look for potential genetic markers linked to increased risk of prostate cancer.
It’s important to note that these results have been presented at a recent scientific meeting but have not yet been published in a peer-reviewed journal and further testing is required in a larger population.
The potential problem with tests like this, as with blood tests, is that sometimes they can falsely label someone as being at ‘increased risk’ or identify a potentially non-life-threatening form of prostate cancer, both of which can cause unnecessary anxiety and investigation of patients. If this test continues to show promise in future larger scale randomised trials, it could be a useful tool for population screening programmes, either alone or in combination with a blood test or imaging scans, but that would be a number of years down the line.
5. Wearable device data
You may be familiar with wearable devices in the fitness space, designed to track step counts, heart rate and sleep metrics and give an overall assessment of a person’s fitness levels. These wearable devices are also making their way into the healthcare space.
There are currently a number of these ongoing in various different settings, collecting patients’ biometric data including step count as a measure of activity levels, heart rate and heart rate variability (HRV) as a measure of fitness and detailed sleep metrics. The aim in future is to use these in conjunction with established assessments such as quality of life questionnaires as a more holistic way to assess the impact various therapies or interventions have on a patient at home.
It is possible, for example, that if a patient is suffering with side effects from their cancer treatment, they might spend more time at home resting, and so there may be an associated drop in step count. Whilst these devices would not be used to diagnose chronic diseases at an earlier stage, they may be used in monitoring on therapy, or post-surgery to predict which patients will require a return to hospital.