Helminth Clearance as Immunological Preparation for Cancer Treatment: Evidence, Timing, and Clinical Protocol Design

Background. Helminth infections polarise host immunity toward Th2 and regulatory T cell (Treg) phenotypes, suppressing the Th1/CD8+ cytotoxic T cell responses that underlie both spontaneous anti-tumour immunity and the efficacy of immune checkpoint inhibitor (ICI) therapy. An estimated 1.5 billion people carry soil-transmitted helminths, with hundreds of millions additionally carrying Schistosoma, Strongyloides, or filarial species. In helminth-endemic regions where cancer incidence is rising, a substantial proportion of patients commencing ICI therapy may carry helminth infections that are unscreened, untreated, and immunologically active at the time of treatment initiation. Core question. Does treating helminth infection before initiating cancer immunotherapy allow immune reconstitution sufficient to improve treatment outcomes? This paper assembles evidence bearing on that question, characterises the timing of post-deworming immune recovery, and designs a clinical protocol and pilot trial for testing the intervention. Evidence summary. Post-deworming immune reconstitution studies demonstrate measurable Th1 cytokine increases and Treg normalisation within 6 weeks of praziquantel...