Among all the cancers studied, only one appears to carry a telltale microbial signature hidden within its tumors: colorectal cancer. New research from the University of East Anglia analyzed whole genome sequencing data from more than 9,000 patients across 22 cancer types and found that colorectal tumors alone consistently host distinct communities of microbes, according to findings published in Science Translational Medicine.
The discovery challenges a widely held assumption in cancer biology — that every cancer type has its own unique microbial fingerprint. "This study changes how we think about the role of microbes in cancer," said lead researcher Dr. Abraham Gihawi of UEA's Norwich Medical School. The team developed computer programs to strip away human DNA from tumor samples and analyze what remained, then cross-referenced those microbial profiles with clinical data about cancer type and patient outcomes.
Colorectal cancer is the fourth most common cancer in the United Kingdom and the second leading cause of cancer death. The microbial signatures the researchers identified were so specific that they could accurately distinguish colorectal tumors from other tumor types. That precision could eventually help doctors diagnose the disease more accurately and understand how aggressive a particular case may be.
The practical implications are significant. As whole genome sequencing becomes more routine in hospitals, examining the microbes present in tumor samples could become a powerful and low-cost addition to existing cancer care. Rather than requiring new tests or expensive equipment, clinicians could extract microbial data from sequencing that is already being performed. For a disease that kills tens of thousands of people each year, any new tool that improves early detection or treatment matching could prove transformative.
