Sept. 29 (UPI) -- Fungi are commonly present in human tumors, and may someday be used as a tool to detect, diagnose and even treat cancer.
That's according to an international team of scientists, which on Thursday unveiled what they said is the first-ever "pan-cancer mycobiome atlas" that describes the links between fungi and 35 types of cancer.
The findings were published in the journal Cell.
The research team, co-led by investigators at the University of California-San Diego School of Medicine and the Weizmann Institute of Science in Rehovot, Israel, noted that little is known about the role of fungal microorganisms, or mycobiota, a part of the human microbiome, in human cancers.
Previous research has long focused on the association between cancer and individual microbes, a news release said.
But much recent attention has centered on the entire human microbiome, particularly in the gut, where more, and more diverse, communities of bacteria, viruses and fungi are found than anywhere else in or on the human body, the release said.
The new analysis of multiple body sites, which revealed fungi linked to cancers, included 17,401 samples of patients' tissues, blood and plasma across 35 types of cancer in four independent populations, the research paper said.
The researchers said they found "significant correlations" between specific fungi and age, tumor subtypes, smoking status, response to immunotherapy and survival measures.
But they said it still must be determined whether the fungi are causally connected.
"The existence of fungi in most human cancers is both a surprise and to be expected," said Rob Knight, the study's co-corresponding author and a professor in the Department of Pediatrics at UC-San Diego School of Medicine.
"It is surprising because we don't know how fungi could get into tumors throughout the body," Knight said. "But it is also expected because it fits the pattern of healthy microbiomes throughout the body, including the gut, mouth and skin, where bacteria and fungi interact as part of a complex community."
Knight also is a professor in the Department of Bioengineering and Computer Science at UC San Diego Jacobs School of Engineering. And he is co-founder of Micronoma, a San Diego-based company developing microbial biomarkers in blood and tissue to diagnose and treat cancers.
The finding that fungi are commonly present in human tumors "should drive us to better explore their potential effects and re-examine almost everything we know about cancer through a 'microbiome lens,'" Dr. Ravid Straussman, the study's co-corresponding author and a principal investigator at Weizmann Institute of Science, said in the release.
A separate study, also appearing in Thursday's issue of the journal Cell, found fungal involvement in gastrointestinal and lung tumors.
Anders B. Dohlman, a doctoral student in biomedical engineering at Duke University in Durham, N.C., is that study's corresponding author.
In lung cancers, for example, Blastomyces was associated with tumor tissues, the researchers involved in that study said. In stomach cancers, there were high rates of Candida; and in colon cancers, the presence of Candida helped predict the spread of disease.
The data arising from this research implicate mycobiota in the development of human gastrointestinal cancers and suggest that "tumor-associated fungal DNA may serve as diagnostic or prognostic biomarkers," the scientists said.