They found evidence that people infected with Toxoplasma gondii or T. gondii had a higher risk of developing rare but highly fatal gliomas.
The parasite can sometimes form cysts in the brain, and the inflammation associated with these cysts may be responsible, the researchers reported in the International Journal of Cancer.
A team of researchers led by epidemiologist James Hodge of the Population Science Division of the American Cancer Society and Anna Kogil of the Cancer Epidemiology Division of the H. Lee Moffit Cancer Center and the Florida Research Institute looked at the connection. between antibodies to T. gondii in blood samples and the risk of glioma in two groups of people.
“In both cohorts, we observed a putative positive association between seropositivity for T. gondii antibodies and glioma risk,” the researchers wrote. Glioma associations are stronger for people who have higher levels of T. gondii antibodies.
T. gondii is a common parasite that most commonly infects humans through contaminated food or water from raw or unprocessed meat from infected animals. According to the study, 20 to 50% of the world’s population has been exposed to the parasite.
Gliomas make up the majority – 80% – of malignant brain tumors. Glioblastomas are the most common subtype. Glioblastomas have a five-year relative survival of only 5%.
“Our findings provide the first promising evidence for a link between T. gondii infection and glioma risk, results that need to be confirmed in independent studies,” the researchers wrote.
“This does not mean that T. gondii definitely causes glioma in all situations. Some people with glioma do not have antibodies to T. gondii and vice versa,” Hodge said in a statement.
“The findings suggest that people with higher exposure to the parasite T. gondii are more likely to develop glioma,” added Coghill. “However, it should be noted that the absolute risk of being diagnosed with glioma remains low and these findings need to be replicated in a larger and more diverse group of individuals.”
If the results of the study are repeated, “reducing exposure to this common food pathogen would offer the first tangible opportunity to prevent this highly aggressive brain tumor,” the researchers said.
CNN’s Katie Hunt contributed to this report.