ATLANTA, Ga. — Eating undercooked meat can make you sick and even put you in the hospital. A concerning study finds parasites in these foods also appear to have a connection to a rare form of brain cancer. Researchers from the American Cancer Society (ACS) say people who have been infected by toxoplasma gondii have a higher risk of developing glioma — one of deadliest forms of cancer.
T. gondii is a common food-borne parasite which infects people eating poorly cooked meat. Infections can even lead to cysts forming in the patient’s brain. Researchers find that cancer patients diagnosed with glioma are more likely to have antibodies for T. gondii in their systems. This indicates that the patient had a previous infection and has developed a resistance to the pathogen.
Investigators James Hodge and Anna Coghill examined 111 people in the ASC Cancer Prevention Study-II and 646 participants from the Norwegian Cancer Registry’s Janus Serum Bank. The results reveal patients showing signs of a previous T. gondii infection increases glioma risk later on.
“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,” notes Hodge in a media release.
“The findings do suggest that individuals with higher exposure to the T. gondii parasite are more likely to go on to develop glioma,” adds Coghill. “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.”
How deadly is this form of brain cancer?
Developing glioma is both extremely rare and very deadly in humans. The ACS report notes that there were around 300,000 cases of brain or nervous system cancer globally in 2018. Another 241,000 died of these cancers that year. Researchers say 80 percent of malignant brain tumors are gliomas and the five-year survival rate is a grim five percent.
The study notes patients in the CPS-II study had an average age of 70 years-old. The average age of the Janus report was 40 years-old.
“If future studies do replicate these findings, ongoing efforts to reduce exposure to this common pathogen would offer the first tangible opportunity for prevention of this highly aggressive brain tumor,” the authors conclude.
The study appears in the International Journal of Cancer.