Pancreatic cancer is not one of the most frequently diagnosed cancers, but it is one of the most fatal due to its early local extension and metastatic behaviour. Several of the reasons for this high fatality rate are the late diagnosis of the disease, especially since symptoms are unspecific and appear rather late, and limited therapeutic options.
Researchers from the Spanish National Cancer Research Centre (CNIO) led byNuria Malats and the European Molecular Biology Laboratory (EMBL) in Heidelberg, led by Peer Bork, have discovered a molecular signature of 27 microorganisms in stool samples that could predict whether patients are at high risk of pancreatic adenocarcinoma, the most common pancreatic cancer, and even diagnose patients with earlier stages of the disease.
A patent has been granted to develop a pancreatic cancer diagnostic tool that detects these microbial genomes in stool samples in a fast, non-invasive and economical way. This week, the journalGut, a prominent journal in gastroenterology and hepatology, published a study.
Detecting pancreatic cancer early
Although pancreatic cancer is rare, it occurs in the late stages of the illness, when tumours usually cannot be removed by surgery. Therefore, it is urgent need for non-invasive, specific, and affordable tests to detect the disease early and prolong patient survival.
"In many cases, once pancreatic cancer is detected, it is too late. We need to diagnose the disease at an earlier stage, before symptoms arise. To this end, we must develop and define the population at risk, as well as have good screening tests to detect the cancer when it is still curable.
Recent data suggests that the microorganisms that coexist with cells in the human body the microbiome may play a role in the origin and development of the pancreatic ductal adenocarcinoma.
136 individuals (57 newly diagnosed patients, 50 controls, and 27 patients with chronic pancreatitis) who were deeply characterized at epidemiological and clinical levels, from whom samples of saliva, faeces, and pancreatic tissue were obtained. The subjects were recruited from two Spanish hospitals in Madrid (Ramon y Cajal Hospital) and Barcelona (Vall Hebron Hospital).
The most thorough study of the microbiome in pancreatic cancer
According to Malats and Bork, this oral microbiome was not associated with pancreatic cancer, but faecal microbes. "We have done a comprehensive biostatistical and bioinformatics analysis to prove that 27 stool-derived microbes differ greatly in their most advanced and early stages," they said. It was found in an independent study conducted in two German laboratories, the Frankfurt (Goethe University Hospital) and Erlangen (University Clinic Erlangen, and in 5792 f
However, pancreatic cancer is a disease with a very complex aetiology and high risk factors, such as age, obesity, chronic pancreatitis, smoking, high alcohol consumption, blood type, and family history of cancer. In the study, authors determined for these clinical and demographic variables, which they said, would be superior. "This level of analysis is unprecedented in pancreatic cancer metagenome studies.
The high predictive value of this stool gene signature might serve as a biomarker to define the vulnerable population and, if validated in clinical trials, it might be used for early diagnosis of pancreatic cancer. "Currently, screening programs are targeted to families with pancreatic cancer aggregation, which represents only 10% of the burden of the disease. "The inclusion of a stool analysis to identify the identified microbial signature might help to identify the rest of the population at risk, according to researchers.