The new technique, which comes from the University of California – San Diego, works on the basis of a straightforward blood draw. When the blood is analyzed, the presence of microbial DNA could reveal whether the patient has cancer and then which type of cancer. The technique has produced accurate results, even for detecting signs of cancer at the early stages.
The basis of the technique came from an earlier study where it was shown that microorganisms invaded a majority of pancreatic cancers. In addition, certain types of microbes were found to be able to break down chemotherapy drugs. This led to the idea that examining a patient’s microbiome could play a role in cancer detection.
This represented a shift in thinking, according to one of the scientists involved, Professor Rob Knight, who says: “Almost all previous cancer research efforts have assumed tumors are sterile environments, and ignored the complex interplay human cancer cells may have with the bacteria, viruses and other microbes that live in and on our bodies.”
To develop the technique, the researchers examined 18,116 tumor samples, drawn from 10,481 patients. The patients had 33 different cancer types. By using a computer model, the analysis of the data revealed a series of distinct microbial signatures associated with specific cancer types.
For example, there was a connection between the bacterium Fusobacterium species and gastrointestinal cancers. The anaerobic Gram-negative organism has previously been linked with skin ulcers. As a second example, the researchers found an association between Faecalibacterium species and colon cancer. This Gram-positive anaerobe has previously been linked with Crohn’s disease.
Such data is now being used to develop machine learning algorithms and with this the potential for a new, rapid cancer detection technology based on liquid biopsies.
The research has been published in the science journal Nature. The peer-reviewed study is titled: “Microbiome analyses of blood and tissues suggest cancer diagnostic approach.”
