The researchers found that in many cases the same strain of bacteria was present in tumours in both the colon and liver in patients where the cancer had metastasised
A team of researchers working at Harvard University has found evidence that suggests a certain type of bacteria found in colon cancer tumours makes its way to tumours in other body parts by traveling with the metastasizing cells. In their paper, ‘Analysis of Fusobacteriumpersistence and antibiotic response in colorectal cancer’, published in the journal Science, the group describes their study of the bacteria and its possible link to being a cause of colon cancer.
Prior research has shown that bacteria exist alongside tumour cells for various types of cancers, causing some in the medical field to wonder if they are actually the cause of tumour formation. One such type of bacteria, Fusobacterium nucleatum, has been found to exist alongside colon cancer tumour cells. In this latest study, the researchers hypothesised if the same bacteria might exist alongside colon cancer tumour cells that have migrated to another part of the body, specifically, the liver.
To find out, the researchers collected tissue samples from actual patients. In so doing, they found that in many cases the same strain of bacteria was present in tumours in both the colon and liver in patients where the cancer had metastasised. They also found that patients who had colon cancer but had no evidence of the bacteria in their tumours, also did not have the bacteria in their liver tumours.
Next, the researchers implanted tumours from human patients into healthy rats. In so doing they found that those tumours which also had the bacteria took hold and began growing. Those tumours that did not have the bacteria, on the other hand, failed to take hold.
The team then tested the possibility of treating the colon cancer in mice by treating them with an antibiotic known to kill F nucleatum. They found that doing so did indeed slow the growth of the tumour.
The researchers suggest that it appears that the bacteria do travel with the tumour cells to a new site and remain with new tumours that develop in those sites. They suggest further that it might be possible that the bacteria aides in colonisation at the new site. More research will be done to determine if the bacteria actually play a role in the development of tumours.