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An international team of researchers has identified a microbiome gene signature that can be used to identify individuals that have a high risk of developing pancreatic ductal adenocarcinoma (PDAC)
PDAC is the most common form of pancreatic cancer and is the 12th most common type of cancer worldwide. The American Cancer Society estimates around 62,10 people will be diagnosed with pancreatic cancer in 2022, and 49,830 people will die of the disease this year.
The outlook for patients diagnosed with pancreatic cancer is particularly poor, with fewer than 1 in 20 patients surviving for more than 5 years after diagnosis. The high mortality rate is not due to the lack of treatment options but because those treatments are not effective in the advanced stages of the disease when pancreatic cancer is usually diagnosed. Most diagnoses are made when the cancer is at the advanced stages, as pancreatic cancer rarely produces symptoms in the early stages of the disease when treatments could be effective.
Currently, pancreatic cancer is diagnosed from scans, biopsies, and urine and blood samples once symptoms are experienced. There is a clear need for non-invasive diagnostic tests that can be performed on people at risk of developing pancreatic cancer to allow an early diagnosis. Currently, there are no clinical screening tools for PDAC that are able to detect the disease in the early stages.
Researchers at the Spanish National Cancer Research Centre (CNIO) and European Molecular Biology Laboratory (EMBL) in Germany investigated whether the presence of certain microbes in the gut could be used as a diagnostic tool for pancreatic cancer. The researchers conducted a case-control study using data from 136 individuals, 50 of whom were used as a control group, 57 had recently been diagnosed with PDAC, and 27 patients had chronic pancreatitis – a risk factor for pancreatic cancer.
The researchers found no signature for pancreatic cancer in the oral microbiome but did identify a fecal microbiome signature from stool samples that was not present in the pancreatitis patients and the control group. The researchers also controlled for obesity, diabetes, and other risk factors to avoid biases.
The signature was based on 27 stool-derived microbes was was present in patients at all stages of the disease. The signature also did not appear to be a consequence of impaired pancreatic function. The researchers found that individuals with pancreatic cancer had abundant populations of Methanobrevibacter smithii, Fusobacterium nucleatum, Alloscardovia omnicolens, Veillonella atypica, and Bacteroides, and populations of Faecalibacterium prausnitzii, Bacteroides coprocola, Bifidobacterium bifidum, or Romboutsia timonensis were depleted.
The researchers have recently submitted a patent application for a rapid non-invasive pancreatic cancer diagnostic kit that can be used to identify the microbiome signature from stool samples.
You can read more about the study in the paper – A faecal microbiota signature with high specificity for pancreatic cancer – which was recently published in Gut. DOI: 10.1136/gutjnl-2021-324755