A simple urine test that could detect pancreatic cancer much earlier than at present has been developed by scientists. They found a protein "signature" only present in people with the disease.
Pancreatic cancer is often very advanced by the time it is diagnosed - and only 3% of patients are alive five years after diagnosis.
Cancer charities welcomed the study, published in Clinical Cancer Research, saying a test was "much needed". More than 80% of people with the disease are diagnosed when it has already spread, so they are not eligible for surgery to remove the tumor - currently the only potential cure. Those at higher risk include people with a family history of the cancer, heavy smokers, obese people and people over 50 who are newly diagnosed with diabetes.
Breakthrough Urine Test
While there is a protein in the blood, CA19-9, which some pancreatic cancers secrete, it is not produced by all types of tumors. This is why, at the moment, it is used by doctors alongside other tests to help diagnose patients who are already suspected of having the disease. And while some research has shown CA19-9 levels might be raised in patients up to two years before they are diagnosed, it is not yet accurate enough to use to diagnose patients.
So, a team of scientists at Barts Cancer Institute, Queen Mary University of London, decided to look for proteins in urine that could help identify patients with early-stage pancreatic cancer. One of the advantages of a urine-based test is that urine is, in general, much less complex to analyze and less invasive to collect.
To find out if there were any measurable signs linked to cancer, the team, led by Dr Tatjana Crnogorac-Jurcevic, looked at levels of 1,500 proteins in urine samples from 18 patients: six of whom, had pancreatic cancer, six, who had a benign inflammatory disease of the pancreas called chronic pancreatitis (which can increase your risk of developing pancreatic cancer), and six healthy individuals.
They noticed that three proteins – LYVE-1, REG1A and TFF1 – were higher in pancreatic cancer patients.
These proteins, they suspected, could potentially be used to help distinguish patients with early-stage pancreatic cancer from healthy individuals.
And further studies they carried out, in a larger number of patients, showed tentative signs that this might be the case.
However, we have to admit that there is still a long way to go before we know if this research could lead to a test that would help detect pancreatic cancer early. The study only validated how well these three proteins predicted things using 488 urine samples, from 192 patients with pancreatic cancer, 92 patients with chronic pancreatitis and 87 healthy volunteers.
This analysis showed that urine from patients with pancreatic cancer showed elevated levels of each of the three proteins when compared to healthy individuals. So in combination, the set of proteins seems to be fairly good at differentiating healthy individuals from patients.
But – crucially – the protein levels couldn’t reliably tell the difference between chronic pancreatitis and pancreatic cancer patients. And this could be a fairly big stumbling block for a useful test, and might have implications for who it could potentially benefit.
Co-author Prof Nick Lemoine of the Barts Cancer Institute, said: "It's really exciting because for the first time we might be able to bring forward the window of opportunity for patients with pancreatic cancer - from something that is advanced and late stage to something that is early stage and potentially curable by surgery. "Patients are usually diagnosed when the cancer is already at a terminal stage, but if diagnosed at stage 2, the survival rate is 20%, and at stage 1, the survival rate for patients with very small tumors can increase up to 60%."
The Pancreatic Cancer Research Fund said this was "an exciting finding" and that an early diagnostic test was "much needed".
Fiona Osgun, of Cancer Research UK, said: "At the moment, we're a long way from knowing if this research could lead to a test that would help detect pancreatic cancer at an early stage, or who that test might benefit.” But research like this is vital as there's been little progress in improving survival for pancreatic cancer, and innovative approaches are needed."
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