The presence of oral bacteria in so-called cystic pancreatic tumours is associated with the severity of the tumour, a Swedish study has found.
Pancreatic cancer is one of the most lethal cancers in the west. The disease is often discovered late, which means that in most cases the prognosis is poor. But not all pancreatic tumours are cancerous. For instance, there are so-called cystic pancreatic tumours (pancreatic cysts), many of which are benign. A few can, however, become cancerous.
It is currently difficult to differentiate between these tumours. To rule out cancer, many patients undergo surgery, which puts a strain both on the patient and on healthcare services.
Now, however, researchers at Karolinska Institutet have found that the presence of bacteria inside the cystic tumours is linked to how severe the tumour is—and they have published their findings in Gut.
The researchers examined the presence of bacterial DNA in fluid from pancreatic cysts in 105 patients and compared the type and severity of the tumours. What they found was that the fluid from the cysts with high-grade dysplasia and cancer contained much more bacterial DNA than that from benign cysts.
To identify the bacteria, the researchers sequenced the DNA of 35 of the samples that had high amounts of bacterial DNA. They found large variations in the bacterial composition between different individuals, but also a greater presence of certain oral bacteria in fluid and tissue from cysts with high-grade dysplasia and cancer.
“We were surprised to find oral bacteria in the pancreas, but it wasn’t totally unexpected,” said Dr Sällberg Chen. “The bacteria we identified has already been shown in an earlier, smaller study to be higher in the saliva of patients with pancreatic cancer.”
He added that the results could hopefully help to improve the diagnosis and treatment of pancreatic cancer.