PARIS, March 9. (Benin News) –
A specific panel of gut microbes can identify the presence of pancreatic cancer at any stage of the disease, according to a study published online in the journal “Gut.” According to the researchers, these results offer hope for a new non-invasive method of diagnosing this difficult-to-treat disease, the detection of which currently relies on invasive procedures.
Pancreatic cancer is the twelfth most common cancer in the world, but its incidence is expected to increase over the next two decades. The most common form of the disease is adenocarcinoma of the pancreatic duct, the prognosis of which is poor, since less than one in 20 patients survives 5 years or more.
This is largely due to the fact that the diagnosis is usually made at an advanced stage of the disease and in the absence of effective treatment options. CT scans, tissue, urine and blood samples are used to diagnose it. But, according to the researchers, there is an urgent need to find less invasive ways to detect it, and at an earlier stage.
Recent data suggests that changes to the microbiome – the trillions of bacteria, fungi and other microbes that populate the digestive tract – may play a role in its development and progression.
To investigate this further, the researchers analyzed 100 saliva samples and 212 stool and pancreatic tissue samples from 57 Spanish adults who were diagnosed with the ductal form recently and before treatment – 25 with early-stage disease and 32 with advanced disease; 50 healthy people matched for age and sex; and 29 people with chronic pancreatitis, a known risk factor for pancreatic cancer.
Gut microbes were more informative than oral microbes. After taking into account known risk factors such as smoking, alcohol consumption, obesity and diabetes, a different microbial profile was observed in stool samples from people with ductal pancreatic cancer. compared to people with chronic pancreatitis and those without either disease.
Machine learning techniques have identified characteristic enrichment in some species and relative rarity in others. Methanobrevibacter smithii”, “Fusobacterium nucleatum”, “Alloscardovia omnicolens”, “Veillonella atypica”, and “Bacteroides finegoldii” were abundant in stool samples from cancer patients, while “Faecalibacterium prausnitzii”, “Bacteroides coprocola”, “Bifidobacterium bifidum” or “Romboutsia timonensis” were depleted.
This microbial profile consistently identified patients with the disease regardless of its degree of progression, suggesting that characteristic microbiome signatures emerge at an early stage and that the stool microbiome may detect the disease at its earliest stage. , explain the researchers.
Predictive ability was assessed by the area under the receiver operating characteristic curve (ROCOC), a graphical representation of a test’s effectiveness in identifying and ruling out a given disease. An area under the ROC curve of 0.5 corresponds to chance; 1 equals perfect accuracy. In this case, the AUROC curve reached 0.84.
Accuracy increased further, to 0.94, when the microbial profile was combined with blood levels of carbohydrate antigen 19-9, a substance indicative of pancreatic cancer, but also other conditions, and the the only current non-invasive test approved by the US drug regulator, the Food and Drug Administration (FDA), to monitor the progression of pancreatic cancer.
The predictive ability of the microbiome profile was validated in a separate group of 76 German subjects, of whom 44 had pancreatic duct cancer and 32 did not. It was then validated once morest publicly available data from 25 studies involving 5,792 samples covering 9 different health conditions, including other cancers and type 2 diabetes, a risk factor for breast cancer. pancreas.
The microbial profile of mouth, stool and pancreatic tissue samples from patients with ductal pancreatic cancer were similar, suggesting that they may be closely related.
“Our data are strictly observational and cross-sectional,” emphasize the researchers. “Nevertheless, there are strong indications that the identified changes in the faecal microbiome are not a simple consequence of impaired pancreatic function or its systemic effects, although indirect effects cannot be ruled out.” they.
And they add that, given previous research on a possible link between pancreatic cancer and the gut microbiome, “we believe that the presented panel of bacterial species associated with pancreatic cancer is a good candidate for a possible link between the pancreatic cancer and the gut microbiome. [al cáncer de páncreas ductal] may be relevant beyond its use for diagnosis, providing promising future entry points for disease prevention and therapeutic intervention”.
In a linked comment, Drs. Rachel Newsome and Christian Jobin of the University of Florida caution that, “although promising, these results have limited clinical value due to the cross-sectional nature of the study, so the predictive markers should be tested using a prospective cohort before reaching a conclusion on their clinical impact”.
They add that further research would be needed to determine if the microbial profile is specific to pancreatic cancer and not shared with other cancers. Nonetheless, this research “represents an important contribution to the generation of predictive markers for pancreatic duct cancer and highlights the key role of the microbiota in cancer surveillance…” and represents significant progress for non-invasive cancer screening,” write- they.
