Individuals who have the brain cancer type glioma are more likely to have antibodies to T. gondii, indicating that they have had a previous infection, compared to a similar group that was cancer free, new research1 has found. The results suggest that reducing exposure to this common food-borne pathogen could provide a modifiable risk factor for highly aggressive brain tumors in adults.
Led by James Hodge, JD, MPH and Anna Coghill, Ph.D. investigators looked at the association between Toxoplasma gondii (T. gondii) antibodies (measured several years before the cancer was diagnosed) and the risk of developing a glioma. T. gondii is a common parasite that is most commonly acquired from undercooked meat and may lead to the formation of cysts in the brain.
The study notes an association between T. gondii antibodies and glioma was similar in two demographically different groups of people: the CPS-II cases were approximately 70 years old at the time of blood draw, while those in the Janus cohort were approximately 40 years old.
This does not mean that T. gondii definitely causes glioma in all situations. Some people with glioma have no T. gondii antibodies, and vice versa,
The findings do suggest that individuals with higher exposure to the T. gondii parasite are more likely to go on to develop glioma. However, it should be noted that the absolute risk of being diagnosed with a glioma remains low, and these findings need to be replicated in a larger and more diverse group of individuals,
Although glioma is a relatively rare disease, it is a highly fatal cancer. Globally in 2018, there were an estimated 300,000 incident cases and 241,000 deaths due to brain and other nervous system cancers.
The majority (80%) of malignant brain tumors are gliomas, for which the estimated five-year relative survival rate is a stark 5%.
Hodge JM, Coghill AE, Kim Y, Bender N, Smith-Warner S, Gapstur S, Teras LR, Grimsrud TK, Waterboer T, Egan KM. Toxoplasma Gondii Infection and the Risk of Adult Glioma in Two Prospective Studies, 2021. Int. J. Cancer. 2021; 1– 8 ↩︎