Parasites

Overview Several parasites were investigated for a possible role in oncogenesis. Among the well‐known parasitic infections, Schistosoma haematobium was proved to play an important role in developing urinary bladder cancer. Moreover, Schistosoma japonicum is classified as a colorectal carcinogen especially in the Far East. Other class of parasites, such as helminths Clonorchis and Opisthorchis are proved to induce hepatobiliary cancer. In Africa, a strong correlation between Ebstein‐Barr virus infection and Burkitt lymphoma is present, with an evident enhancing role for Plasmodium falciparum . Chronic inflammation was incriminated to be the most accepted mechanism for parasite‐induced cancer; however, the roles of certain carcinogens, oncogenes, DNA mutations, and others were all approved as mechanisms enhancing carcinogenesis in parasitic infections. Strikingly, despite the above‐mentioned data, it seemed that certain parasites could modulate the host immune response in a manner that would lead to cancer regression or prevention. This is in the prospect of revaluation of the clinical importance of infectious agents; an issue that requires future concern.