Scientists have developed a pancreatic cancer blood test that could detect disease earlier, potentially improving survival if validated in larger studies.
Around 10,500 people are diagnosed with the disease in the UK each year, but it is hard to treat and diagnose.
Because it is often found late, only 10 per cent live longer than five years after diagnosis, with more than half dying within three months of diagnosis.
Researchers from the University of Pennsylvania and the Mayo Clinic say the test could detect pancreatic ductal adenocarcinoma, the most common and one of the most aggressive forms of the disease, in its earliest stages, giving doctors time to treat it and increase patients’ chance of survival.
The team tested stored blood samples from people with pancreatic cancer and from people without it.
They examined two markers already used in medicine, CA19-9 and THBS2.
On their own these are not accurate enough for screening, as CA19-9 can be high in non-cancer conditions such as pancreatitis (inflammation of the pancreas) or bile duct problems, and some people do not produce it because of their genes. THBS2 is a protein linked with tissue changes around tumours.
The researchers discovered two additional proteins in the blood, ANPEP and PIGR, that were higher in people with early pancreatic cancer than in healthy volunteers.
When the team combined all four markers into one test, it correctly identified pancreatic cancer about 92 per cent of the time, at a 5 per cent false-positive rate.
For early-stage cancer, it picked up nearly 8 per cent of cases.
The researchers say the test could be used to screen people at higher risk, such as those with a family history, certain genetic risks, pancreatic cysts or long-term pancreatitis. It also distinguished cancer from non-cancerous conditions like pancreatitis, a key limitation of previous models.
Kenneth Zaret, the study’s lead investigator from the University of Pennsylvania’s Perelman School of Medicine, said: “By adding ANPEP and PIGR to the existing markers, we’ve significantly improved our ability to detect this cancer when it’s most treatable.
“Our retrospective study findings warrant further testing in larger populations, particularly in people before they show symptoms.
“Such ‘prediagnostic’ studies would help determine if the test could be used as a screening tool for people at high risk of developing the disease based on family history, genetic screening results or personal history of pancreatic cysts or pancreatitis.”
However, it could take years before the new blood test has completed the trials and regulatory steps needed for mainstream use.
At present, pancreatic cancer is incurable, with life expectancy just five years from initial diagnosis.
It kills because it aggressively invades nearby organs, blocks the bile and intestinal ducts, and spreads via the blood and lymphatic system to the liver, lungs and abdomen, eventually triggering organ failure.
The pancreas aids digestion and produces hormones, such as insulin and glucagon, which help convert sugar from food into energy. Pancreatic cancer can reduce the gland’s ability to make these hormones, which can lead to unstable blood sugar levels.
Common symptoms include jaundice (yellowing of the skin and eyes), loss of appetite, weight loss, fatigue, a high temperature, feeling or being sick, diarrhoea and constipation.
Research published last year suggested that more than half of patients diagnosed with the six least curable cancers, including lung, liver, brain, oesophageal, stomach and pancreatic, die within a year of diagnosis.
More than 90,000 people are diagnosed with one of these cancers in the UK every year, accounting for nearly half of all common cancer deaths, according to Cancer Research UK.
There are currently no early detection tests and about 80 per cent of people are not diagnosed until the cancer has spread, meaning life-saving treatment is no longer possible.
Last week, Spanish researchers revealed a treatment plan that made pancreatic cancer cells shrink in laboratory mice. However, this requires much more robust testing, meaning it could be years before similar treatments are offered to human patients.
