Scientists have developed a blood test that can detect cancer in people with nonspecific symptoms.
The test could help identify cancer patients earlier, when they are more likely to respond to treatment, and help flag up who could benefit from early access to drugs designed to tackle cancer. The test can tell if the disease has spread.
There is currently no clear way to refer someone with nonspecific symptoms that could be cancer. If a patient can't identify an obvious cause of their symptoms then they will be told to come back if they get worse, but if they can't do that then they will be given a quick cancer diagnosis.
The problem we have had in the past is that if they have cancer, the cancer is growing all the time, and when they come back, the cancer is often advanced.
It's difficult to know how many people fall into this category, but it's likely to be tens of thousands of patients across the UK. We want to give these patients an immediate referral option when they come to the GP.
If you can say you have a cancer, it will make you want to send that patient for an investigation to see if you can find it.
The new test uses a technology called nuclear magnetic resonance (NMR) spectroscopy, which can be used to determine levels of small molecule in the blood. Individuals with cancer have different metabolisms.
In a study published in the journal Clinical Cancer Research, the test correctly detected cancer in 19 out of 20 patients with the disease, and it was done using samples from 300 patients with nonspecific but concerning symptoms of cancer, such as fatigue and weight loss. The ultimate goal is to find the type of tumours they have.
The test could distinguish between patients with different types of cancer, with an accuracy of 94%, making it the first blood test to be able to detect if a person's cancer has spread.
The information changes how you treat patients. Some immunotherapies have been shown to increase survival rates for people with cancer, but they are expensive and have side-effects. We don't want to prescribe them to everyone, but there are patients that would benefit if you could only identify them early enough.
A different type of blood test that aims to detect circulating tumour DNA (ctDNA) is being tested in the National Health Service, but metabolic changes may be detected earlier, while ctDNA technology requires you to know which mutations to look for when finding a tumours.
The next step is to confirm the test's accuracy in a group of British patients with nonspecific symptoms, which could happen within the next two years. The data would be submitted to the regulatory agencies.
