Researchers have found a molecular signature of 27 microorganisms in stool samples that could predict whether patients are at high risk of pancreatic ductal adenocarcinoma, the most common pancreatic cancer, and even diagnose patients with earlier stages of the disease.

A patent has been applied for to develop a pancreatic cancer diagnostic kit that detects these microbial genomes in stool samples in a rapid, non-invasive, and affordable way. The study was published this week in the journal Gut.

Pancreatic cancer is a relatively rare cancer type, but survival rates remain stubbornly low. In the UK, it’s estimated that only 1 in 4 people will survive for one year or more after their diagnosis. One of the key reasons for this is that pancreatic cancer is often diagnosed late because the symptoms are hard to spot and may not appear until later in the progression of the disease.

This comprehensive study regarding the influence of the microbiome on pancreatic cancer, was spearheaded by researchers from the Spanish National Cancer Research Centre (CNIO), led by Núria Malats, PhD, MD, and the European Molecular Biology Laboratory (EMBL) in Heidelberg, led by Peer Bork, PhD.

Sophisticated biostatistical and bioinformatics analyses have allowed us to construct a signature of 27 stool-derived microbes, mostly bacteria, that discriminates very well between cases with pancreatic cancer and controls, both in their most advanced and earliest stages,” say Malats and Bork.

The high predictive value of this stool gene signature could serve as a biomarker to define the population at risk and, if validated in clinical trials, it could be used for early diagnosis of pancreatic cancer.

“This new breakthrough builds on the growing evidence that the microbiome – the collection of microorganisms that live side by side with the cells inside our body – is linked to the development of cancer,” says Helen Rippon, chief executive, Worldwide Cancer Research. “What’s amazing about this discovery is that the microbiome of stool samples from patients could be used to help diagnose pancreatic cancer early. Early detection and diagnosis are just as important an approach to starting new cancer cures as developing treatments.

Currently, screening programs are targeted to families with a history of pancreatic cancer, which represent only 10% of the burden of the disease. The inclusion in these screening programs of a stool analysis to identify the identified microbial signature could help to detect the rest of the population at risk, according to the researchers.

In this new study, the researchers conducted a unique case-control study with 136 individuals (57 newly diagnosed patients, 50 controls, and 27 patients with chronic pancreatitis) who were deeply characterized at epidemiological and clinical levels and from whom samples of saliva, feces and pancreatic tissue were taken to analyze their microbiome. The subjects were recruited from two Spanish hospitals in Madrid (Ramon y Cajal Hospital) and Barcelona (Vall Hebron Hospital).