Scientists have found a way to spot diseases like prostate and ovarian cancer early enough to make treatment more effective
Ask any medical professional and they’re likely to tell you that picking up diseases and conditions as soon as possible is vitally important. Early detection means early treatment, and also the chance to make a speedy change to an unhealthy lifestyle. It’s partly why those hard to spot diseases, such as ovarian cancer, are so difficult to treat – too often we don’t know about them until it’s too late.
Now scientists at Imperial College, London and the University of Vigo, Spain, have created super-sensitive tests that may be able to diagnose diseases when they are still in their earliest stages.
There are already some tests that use biological sensors, also known as biosensors, to show when a person has a particular disease and how severe it is. The difficulty with the biosensors currently in use is that they aren’t always sensitive enough to detect biomarkers when there aren’t many of them, when a disease is still at a very early stage.
For this study the research team used the new biosensor test to find a biomarker that is linked to prostate cancer. The biomarker, Prostate Specific Antigen (PSA), can be an indicator that a patient has this disease.
“We aren’t looking for normal detection of prostate cancer,” explains Professor Molly Stevens, senior author of the study, from the Departments of Materials and Bioengineering at Imperial College London. “We’re looking at situations where the patient has had their prostate removed because of cancer. Any sign of PSA that you then find in the patient’s blood is a sign that the cancer is recurring.”
Professor Stevens said: “It is vital to detect diseases at an early stage if we want people to have the best possible outcomes – diseases are usually easier to treat at this stage, and early diagnosis can give us the chance to halt a disease before symptoms worsen.
“For many diseases, using current technology to look for early signs of disease can be like finding the proverbial needle in a haystack. Our new test can actually find that needle. We only looked at the biomarker for one disease in this study, but we’re confident that the test can be adapted to identify many other diseases at an early stage.”
Monitoring PSA levels at ultralow concentrations can be a vital part of making an early diagnosis of the return of prostate cancer. The difficulties that doctors in this field face are that the detection methods used at the moment aren’t sensitive enough to be really accurate. The new test may be able to give more reliable diagnoses, but the team need to carry out more research to find out just how accurate the test can be.
What does the test involve? The biosensors in this study are nanoscopic-sized gold stars floating in a solution containing proteins that have been derived from blood. Antibodies are attached to the surface of the stars, and these latch on to PSA when they detect it in a sample. An enzyme, glucose oxidase, is attached to a secondary antibody. When it recognises PSA it creates a silver crystal coating on the gold stars. And in an interesting piece of reverse thinking, the silver coating is more apparent when the PSA markers are in low concentrations – so the fewer PSA markers there are, the more clearly they show up in the test. The result is easy for scientists to see using optical microscopes.
“You could, potentially, apply this invention to many, many different diseases,” said Professor Stevens. “So you can imagine that the scope is absolutely massive. So the question ‘how much impact could this have in the future?’ will depend on the disease you’re targeting and the patient group you’re targeting. “ As for the implications of finding out early if a patient has a disease or an infection, there are questions still waiting for an answer, including can you start treatment early, can you completely stop the spread of a cancer, can you treat an infectious disease so that it doesn’t spread?
“There are all sorts of implications and they’re going to be very disease-specific,” says Professor Stevens. “So far we’ve only shown this in a prostate cancer – related application, but really it can go much broader than this. It’s hard to say how long it will be before we start clinical trials, but we’re actively looking to find the right commercial partners to work with.”
“It’s a real priority for us to make sure that this gets through to the patients and actually becomes useful. That’s the key aim of our research really, not just having great academic papers, but also making a real impact on human health.”