Infection-Related Carcinogenesis: The Impact of Parasitic Infections and Antiparasitic Treatment on Cancer Risk - A Systematic Review and Meta-Analysis

Background: Infection-related carcinogenesis accounts for a considerable proportion of the global cancer burden, with parasitic infections increasingly recognized as important oncogenic cofactors. Helminths such as liver flukes and schistosomes are well-established carcinogens, while other parasitic infections demonstrate complex immunomodulatory effects that may influence tumor development.

Objective: This systematic review and meta-analysis aimed to evaluate the association between parasitic infections and cancer risk and to assess the potential impact of antiparasitic treatment on carcinogenesis.

Methods: A comprehensive search of PubMed/MEDLINE, Scopus, Web of Science, and Cochrane Library databases was conducted up to December 2025 following PRISMA 2020 guidelines. Observational and interventional studies assessing parasitic infections and cancer outcomes were included. Data were extracted independently, quality was assessed using the Newcastle–Ottawa Scale, and pooled effect estimates were calculated using random-effects meta-analysis.

Results: Fifty-two studies were included in the qualitative synthesis, with 28 eligible for meta-analysis. Liver fluke infection was strongly associated with cholangiocarcinoma (pooled OR = 4.82; 95% CI: 3.41–6.81), while Schistosoma haematobium infection significantly increased bladder cancer risk (pooled OR = 3.19; 95% CI: 2.12–4.79). Additional associations were observed between Schistosoma japonicum and colorectal cancer and between Plasmodium falciparum and endemic Burkitt lymphoma. Evidence on antiparasitic therapy suggested regression of inflammatory and precancerous lesions following treatment, although data on long-term cancer prevention were limited.

Conclusion: Parasitic infections contribute significantly to infection-related malignancies through chronic inflammation, immune modulation, and genotoxic pathways. Early diagnosis and effective antiparasitic treatment may offer a promising strategy for cancer prevention in endemic regions; however, prospective studies are required to establish long-term benefits