Parasitic Infections and Carcinogenesis: Molecular Mechanisms, Immune Modulation, and Emerging Therapeutic Strategies

Parasitic infections are increasingly recognized as contributors to cancer development, yet the underlying oncogenic mechanisms remain insufficiently understood. Growing evidence from molecular oncology, immunology, and microbiome research suggests that chronic parasitic infections may drive tumorigenesis through sustained inflammation, deregulated signaling pathways, genomic instability, and the release of parasite-derived exosomes that reshape the tumor microenvironment. These insights underscore the need to integrate parasitology with cancer biology to understand infection-associated malignancies better. The aim of this narrative review is to synthesize current knowledge on how selected parasites contribute to cancer development and to highlight emerging therapeutic and diagnostic opportunities. We examine pathogens such as <i>Schistosoma haematobium</i>, <i>Opisthorchis viverrini</i>, <i>Toxoplasma gondii</i>, <i>Plasmodium falciparum</i>, and <i>Leishmania</i> spp., detailing their roles in chronic inflammation, immune modulation, and interactions with tumor-associated immune cells. The review further discusses parasite-induced immunosuppression, coinfections, and their cumulative impact on cancer risk. Additionally, we explore novel therapeutic approaches, including pathway inhibitors, epigenetic drugs, microbiome modulation, and engineered parasites. Future perspectives emphasize parasite-based immunotherapies, long-term epigenetic consequences of infection, and AI-driven multi-omics strategies for identifying oncogenic signatures. This review integrates advances from parasitology and oncology to provide new insights into biomarkers, targeted therapies, and mechanisms of infection-induced tumorigenesis. The literature search covered studies indexed in PubMed, Scopus, and Web of Science up to July 2025.