Scientists have developed a novel method of cancer detection and diagnosis from a single blood draw, even at early stages.
In 2017, Dr Ravid Straussman of the Weizmann Institute of Science’s Molecular Cell Biology Department and his team found live bacteria within pancreatic tumours. These bacteria metabolised a common chemotherapy drug and rendered it ineffective. This shone light onto the possibility that bacteria and viruses may influence prognosis to a larger extent than previously thought.
Recent investigation into these microbes revealed that they are detectable in the blood, even before symptoms arise. Researchers at the University of California San Diego School of Medicine have exploited this to develop a new method to determine who has cancer, and which type, by a simple analysis of microbial DNA in the patient’s blood.
The researchers were granted access to The Cancer Genome Atlas, which stores microbial data as well as genetic information from thousands of patients’ tumours. From this, distinct patterns of microbial DNA were found to be associated with specific types of cancer.
Of course, some of these associations are well-known. For example, human papillomavirus (HPV), has a clear link to cervical cancer. However, the team also found new microbial patterns, or signatures, which were previously unknown and were able to distinguish between specific cancer types. If these were found present in the blood of a patient, this would allow accurate and complete diagnosis.
The team tested thousands of cancer samples on computer-based models which were trained to associate the presence of certain microbial DNA with specific cancer types. They found that the computer was able to recognise a patient’s cancer type, even at early stages, using only a small blood sample.
Gregory Poore, MD/PhD, his supervisor Professor Rob Knight and their team have undertaken the largest-ever attempt (to their knowledge) to identify specific microbial DNA in human blood. They have successfully produced a technique to exploit non-human molecules in the diagnosis of a major human disease. The ability of this technique to detect traces of microbes at the earliest stage of disease progression gives it great therapeutic potential – it is no secret that earlier diagnosis produces a better prognosis.
The team is now looking to introduce their method into the clinical setting and are encouraging other cancer researchers to invest their efforts into the study of microbes in the disease.