Toxoplasma gondii infection/exposure and the risk of brain tumors: A systematic review and meta-analysis.

BACKGROUND

Brain tumors are among the most fatal cancers with substantial morbidity and mortality worldwide. Epidemiologic evidence suggests that infectious agents, especially, protozoan parasite Toxoplasma gondii could be a possible risk factor or contributor. Here, we performed a systematic review and meta-analysis to evaluate the possible association between T. gondii infection/exposure and risk of brain tumors.

METHODS

We searched the PubMed, Embase, Scopus, and Web of Science collection databases from inception through 1st of December 2021. Pooled estimates of odds ratios (ORs) and 95% confidence intervals (CIs) were generated using random effects models. We did the subgroup analysis according to tumor types. Statistical tests for heterogeneity and sensitivity analyses were applied.

RESULTS

A total of seven eligible studies comprising 2323 patients diagnosed with brain tumors and 5131 healthy controls were included in the meta-analysis. T. gondii infection/exposure prevalence was 24.2% (95%CI, 12.7%-41.2) in cases and 12.9% (95%CI, 7.0-22.6%) in control subjects. Pooled analysis showed an overall OR of 1.96 (95%CI, 1.37-2.80), indicating a significant increased risk of brain tumors associated with T. gondii infection/exposure. In subgroup analysis T. gondii infection/exposure was significantly associated with gliomas (OR: 1.64, 95%CI, 1.15-2.33), meningioma (OR: 2.30, 95%CI, 1.0-5.27) and other types of brain tumors (OR: 2.19, 95%CI, 1.02-4.71).

CONCLUSION

This study provides suggestive evidence for an association between T. gondii infection/exposure and brain tumors. Our findings should be further confirmed by well-designed cohort studies with strict control of confounders. Moreover, we suggest that future studies also focus on the effect of T. gondii infection/exposure to the types of brain tumors.