Table 1. Parasites with putative antitumor activity.

Parasite	Cancer	Mechanism of action	Reference
Echinococcus granulosus	Breast and colon cancer	Production of antibodies for the recognition of tumor cells	[5,6]
	Fibrosarcoma	Not clear	[37]
Taenia crassiceps	Colitis-associated colorectal cancer	Decrease recruitment of inflammatory monocytes and inflammation in colon	[27]
Toxoplasma gondii	Melanoma	Activation of CD8+, NK cells, and expression of MHC-I and MHC-II in APC	[12]
	Fibrosarcoma	Increase in the activity of cytotoxic T cells	[13]
	Melanoma and lung cancer	Suppression of neovascularization via induction of hypoxia and avascular necrosis	[31,32]
Trichinella spiralis	Melanoma	Reduction of lung metastasis through CXCL9, CXCL10, IL-4, CXCL1 and CXCL13	[30]
	Human hepatoma cell line (HT402) and human chronic myeloid leukemia cell line (K562)	Arrested of the cell cycle in G1 or S phase	[38,39]
Trypanosoma cruzi	Breast and colon cancer	Activation of CD4+ and CD8+ cells and production of antibodies against cancer cells	[8]
	Experimental breast adenocarcinoma	Trypanosoma cruzi calreticulin as a revealer of the presence of tumor cells in the immune system	[9]
	Mammary cancer	Inhibition of proliferation and migration of endothelial cells	[33]
	Melanoma	J18 recombinant protein induces apoptosis through caspase 3	[36]

The possible mechanisms of action of these parasites on blocking the development of different neoplasms has been organized with the purpose of summarizing the advances that have been made over the last years of research in immunotherapy with biological agents in cancer.