Cancer refers to a group of diseases where normal cells grow uncontrollably, causing interruptions to bodily functions that can ultimately lead to death. One can imagine then the importance of having accessible and accurate diagnostic tools due to the severity of these diseases. Currently, there are a variety of tests available for making such diagnoses including biopsies, where suspicious tissue samples are removed to be further analyzed. However, these tests are more likely to provide late rather than early diagnoses, which can affect the responsiveness of patients to treatments such as chemotherapy. Fortunately, a novel test developed by researchers at UCSD may make it possible to obtain diagnoses significantly earlier and through less invasive means.
Microscope image of a very common type of skin cancer.
Image Source: PansLaos
The researchers found that certain cancer types can be diagnosed based solely on microbial DNA, which is found in an individual’s blood. This microbial DNA, the genetic material of microorganisms, refers to fragmented pieces of DNA that could have come from multiple sources including both live or dead microorganisms. They developed a machine learning model to process data from The Cancer Genome Atlas and found that there was a correlation between certain cancer types and the microbial DNA found in one’s blood. This suggests that if an individual has a specific pattern of microbial DNA, they are likely to have the specific cancer associated with that pattern. The researchers then tested these findings on blood samples from patients with known prostate, lung, and skin cancers, as well as from patients without cancer. The results showed that their machine learning models were largely successful in identifying these cancers. In the case of lung cancer, their models were able to correctly identify 86% of samples that had lung cancer and 100% of samples that did not have lung cancer.
The word microbe is an umbrella term that includes bacteria, fungi, and viruses among others. The above image depicts bacteria, a fairly common microbe.
Image Source: Science Photo Library – STEVE GSCHMEISSNER
The results of this study have significant implications. If a simple blood test can produce the same or even better diagnostic results than invasive tests like biopsies, it has the potential to drastically improve cancer patient outcomes. However, the researchers acknowledge that their test would need to be further optimized before it can be made available as a diagnostic tool. They also believe that their findings reveal the overlooked importance of microbes in cancer development, which may guide future research studies.
Featured Image Source: Photographee.eu
